Simpler API for creating CoreStore-managed NSFetchedResultsControllers, useful for external SDK's that require them

fixed Readme

.gitignore

@@ -2,3 +2,8 @@ CoreStoreDemo/CoreStoreDemo.xcodeproj/project.xcworkspace/xcuserdata
 CoreStore.xcodeproj/project.xcworkspace/xcuserdata
 CoreStore.xcodeproj/xcuserdata
 CoreStoreDemo/CoreStoreDemo.xcodeproj/xcuserdata
+Carthage/Build
+CoreStore.xcworkspace/xcuserdata
+.DS_Store
+DerivedData
+*.orig

.gitmodules

@@ -1,3 +1,3 @@
-[submodule "Libraries/GCDKit"]
-	path = Libraries/GCDKit
-	url = git@github.com:JohnEstropia/GCDKit.git
+[submodule "Carthage/Checkouts/GCDKit"]
+	path = Carthage/Checkouts/GCDKit
+	url = https://github.com/JohnEstropia/GCDKit.git

.travis.yml

@@ -0,0 +1,43 @@
+language: objective-c
+osx_image: xcode7.3
+sudo: false
+git:
+  submodules: false
+notifications:
+  email: false
+env:
+  global:
+  - LC_CTYPE=en_US.UTF-8
+  - LANG=en_US.UTF-8
+  matrix:
+    - DESTINATION="OS=9.3,name=iPhone 6s"          SCHEME="CoreStore iOS"     SDK=iphonesimulator9.3  RUN_TESTS="YES" POD_LINT="NO"
+    - DESTINATION="OS=9.0,name=iPhone 6 Plus"      SCHEME="CoreStore iOS"     SDK=iphonesimulator9.3  RUN_TESTS="YES" POD_LINT="NO"
+    - DESTINATION="OS=8.4,name=iPhone 6"           SCHEME="CoreStore iOS"     SDK=iphonesimulator9.3  RUN_TESTS="YES" POD_LINT="NO"
+    - DESTINATION="OS=8.3,name=iPhone 5S"          SCHEME="CoreStore iOS"     SDK=iphonesimulator9.3  RUN_TESTS="YES" POD_LINT="NO"
+    - DESTINATION="OS=8.2,name=iPhone 5"           SCHEME="CoreStore iOS"     SDK=iphonesimulator9.3  RUN_TESTS="YES" POD_LINT="NO"
+    - DESTINATION="OS=8.1,name=iPhone 4S"          SCHEME="CoreStore iOS"     SDK=iphonesimulator9.3  RUN_TESTS="YES" POD_LINT="YES"
+    - DESTINATION="OS=8.1,name=iPhone 4S"          SCHEME="CoreStore iOS7"    SDK=iphonesimulator9.3  RUN_TESTS="YES" POD_LINT="YES"
+    - DESTINATION="arch=x86_64"                    SCHEME="CoreStore OSX"     SDK=macosx10.11         RUN_TESTS="YES" POD_LINT="NO"
+    - DESTINATION="OS=2.2,name=Apple Watch - 42mm" SCHEME="CoreStore watchOS" SDK=watchsimulator2.2   RUN_TESTS="NO"  POD_LINT="NO"
+    - DESTINATION="OS=9.2,name=Apple TV 1080p"     SCHEME="CoreStore tvOS"    SDK=appletvsimulator9.2 RUN_TESTS="YES" POD_LINT="NO"
+before_install:
+  - gem install cocoapods --no-rdoc --no-ri --no-document --quiet
+  - gem install xcpretty --no-rdoc --no-ri --no-document --quiet
+  - curl -OlL "https://github.com/Carthage/Carthage/releases/download/0.11/Carthage.pkg"
+  - sudo installer -pkg "Carthage.pkg" -target /
+  - rm "Carthage.pkg"
+before_script:
+  - carthage update --use-submodules
+script:
+  - set -o pipefail
+  - xcodebuild -version
+  - xcodebuild -showsdks
+  - if [ $RUN_TESTS == "YES" ]; then 
+      xcodebuild -workspace CoreStore.xcworkspace -scheme "$SCHEME" -sdk "$SDK" -destination "$DESTINATION" -configuration Debug ONLY_ACTIVE_ARCH=NO clean test | xcpretty -c;
+      xcodebuild -workspace CoreStore.xcworkspace -scheme "$SCHEME" -sdk "$SDK" -destination "$DESTINATION" -configuration Release ONLY_ACTIVE_ARCH=NO clean test | xcpretty -c;
+    fi
+  - xcodebuild -workspace "CoreStore.xcworkspace" -scheme "CoreStore iOS" -sdk "iphonesimulator9.3" -destination "OS=9.3,name=iPhone 6s" -configuration Debug ONLY_ACTIVE_ARCH=NO clean test | xcpretty -c;
+  - xcodebuild -workspace "CoreStore.xcworkspace" -scheme "CoreStore iOS" -sdk "iphonesimulator9.3" -destination "OS=9.3,name=iPhone 6s" -configuration Release ONLY_ACTIVE_ARCH=NO clean test | xcpretty -c;
+  - if [ $POD_LINT == "YES" ]; then
+      pod lib lint --quick;
+    fi

Cartfile

@@ -0,0 +1 @@
+github "JohnEstropia/GCDKit" == 1.2.5

Cartfile.resolved

@@ -0,0 +1 @@
+github "JohnEstropia/GCDKit" "1.2.4"

CoreStore.podspec

@@ -1,16 +1,22 @@
 Pod::Spec.new do |s|
     s.name = "CoreStore"
-    s.version = "1.0.1"
+    s.version = "1.6.8"
     s.license = "MIT"
-    s.summary = "Simple, elegant, and smart Core Data programming with Swift"
+    s.summary = "Unleashing the real power of Core Data with the elegance and safety of Swift"
     s.homepage = "https://github.com/JohnEstropia/CoreStore"
     s.author = { "John Rommel Estropia" => "rommel.estropia@gmail.com" }
     s.source = { :git => "https://github.com/JohnEstropia/CoreStore.git", :tag => s.version.to_s }
 
     s.ios.deployment_target = "8.0"
+    s.osx.deployment_target = "10.10"
+    s.watchos.deployment_target = "2.0"
+    s.tvos.deployment_target = "9.0"
 
     s.source_files = "CoreStore", "CoreStore/**/*.{swift}"
-    s.frameworks = "Foundation", "UIKit", "CoreData"
+    s.osx.exclude_files = "CoreStore/Observing/*.{swift}", "CoreStore/Internal/FetchedResultsControllerDelegate.swift", "CoreStore/Internal/CoreStoreFetchedResultsController.swift", "CoreStore/Convenience Helpers/NSFetchedResultsController+Convenience.swift"
+    s.frameworks = "Foundation", "CoreData"
     s.requires_arc = true
-    s.dependency "GCDKit", "1.1.1"
+    s.pod_target_xcconfig = { 'OTHER_SWIFT_FLAGS' => '-D USE_FRAMEWORKS' }
+    
+    s.dependency "GCDKit", "1.2.5"
 end

CoreStore.xcodeproj/xcshareddata/xcschemes/CoreStore OSX.xcscheme

@@ -0,0 +1,99 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "0710"
+   version = "1.3">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "B52DD1731BE1F8CC00949AFE"
+               BuildableName = "CoreStore.framework"
+               BlueprintName = "CoreStore OSX"
+               ReferencedContainer = "container:CoreStore.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES">
+      <Testables>
+         <TestableReference
+            skipped = "NO">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "B52DD17C1BE1F8CC00949AFE"
+               BuildableName = "CoreStoreTests.xctest"
+               BlueprintName = "CoreStoreTests OSX"
+               ReferencedContainer = "container:CoreStore.xcodeproj">
+            </BuildableReference>
+         </TestableReference>
+      </Testables>
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "B52DD1731BE1F8CC00949AFE"
+            BuildableName = "CoreStore.framework"
+            BlueprintName = "CoreStore OSX"
+            ReferencedContainer = "container:CoreStore.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
+      <AdditionalOptions>
+      </AdditionalOptions>
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      launchStyle = "0"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES">
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "B52DD1731BE1F8CC00949AFE"
+            BuildableName = "CoreStore.framework"
+            BlueprintName = "CoreStore OSX"
+            ReferencedContainer = "container:CoreStore.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
+      <AdditionalOptions>
+      </AdditionalOptions>
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "B52DD1731BE1F8CC00949AFE"
+            BuildableName = "CoreStore.framework"
+            BlueprintName = "CoreStore OSX"
+            ReferencedContainer = "container:CoreStore.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>

CoreStore.xcodeproj/xcshareddata/xcschemes/CoreStore iOS.xcscheme

@@ -16,21 +16,21 @@
                BuildableIdentifier = "primary"
                BlueprintIdentifier = "2F03A52F19C5C6DA005002A5"
                BuildableName = "CoreStore.framework"
-               BlueprintName = "CoreStore"
+               BlueprintName = "CoreStore iOS"
                ReferencedContainer = "container:CoreStore.xcodeproj">
             </BuildableReference>
          </BuildActionEntry>
          <BuildActionEntry
             buildForTesting = "YES"
-            buildForRunning = "YES"
+            buildForRunning = "NO"
             buildForProfiling = "NO"
             buildForArchiving = "NO"
-            buildForAnalyzing = "YES">
+            buildForAnalyzing = "NO">
             <BuildableReference
                BuildableIdentifier = "primary"
                BlueprintIdentifier = "2F03A53A19C5C6DA005002A5"
                BuildableName = "CoreStoreTests.xctest"
-               BlueprintName = "CoreStoreTests"
+               BlueprintName = "CoreStoreTests iOS"
                ReferencedContainer = "container:CoreStore.xcodeproj">
             </BuildableReference>
          </BuildActionEntry>
@@ -48,7 +48,7 @@
                BuildableIdentifier = "primary"
                BlueprintIdentifier = "2F03A53A19C5C6DA005002A5"
                BuildableName = "CoreStoreTests.xctest"
-               BlueprintName = "CoreStoreTests"
+               BlueprintName = "CoreStoreTests iOS"
                ReferencedContainer = "container:CoreStore.xcodeproj">
             </BuildableReference>
          </TestableReference>
@@ -58,7 +58,7 @@
             BuildableIdentifier = "primary"
             BlueprintIdentifier = "2F03A52F19C5C6DA005002A5"
             BuildableName = "CoreStore.framework"
-            BlueprintName = "CoreStore"
+            BlueprintName = "CoreStore iOS"
             ReferencedContainer = "container:CoreStore.xcodeproj">
          </BuildableReference>
       </MacroExpansion>
@@ -80,7 +80,7 @@
             BuildableIdentifier = "primary"
             BlueprintIdentifier = "2F03A52F19C5C6DA005002A5"
             BuildableName = "CoreStore.framework"
-            BlueprintName = "CoreStore"
+            BlueprintName = "CoreStore iOS"
             ReferencedContainer = "container:CoreStore.xcodeproj">
          </BuildableReference>
       </MacroExpansion>
@@ -98,7 +98,7 @@
             BuildableIdentifier = "primary"
             BlueprintIdentifier = "2F03A52F19C5C6DA005002A5"
             BuildableName = "CoreStore.framework"
-            BlueprintName = "CoreStore"
+            BlueprintName = "CoreStore iOS"
             ReferencedContainer = "container:CoreStore.xcodeproj">
          </BuildableReference>
       </MacroExpansion>

CoreStore.xcodeproj/xcshareddata/xcschemes/CoreStore iOS7.xcscheme

@@ -0,0 +1,104 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "0700"
+   version = "1.3">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "B5D9E2ED1CA2C317007A9D52"
+               BuildableName = "CoreStore_iOS7.framework"
+               BlueprintName = "CoreStore iOS7"
+               ReferencedContainer = "container:CoreStore.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "NO"
+            buildForProfiling = "NO"
+            buildForArchiving = "NO"
+            buildForAnalyzing = "NO">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "2F03A53A19C5C6DA005002A5"
+               BuildableName = "CoreStoreTests.xctest"
+               BlueprintName = "CoreStoreTests iOS"
+               ReferencedContainer = "container:CoreStore.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES">
+      <Testables>
+         <TestableReference
+            skipped = "NO">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "2F03A53A19C5C6DA005002A5"
+               BuildableName = "CoreStoreTests.xctest"
+               BlueprintName = "CoreStoreTests iOS"
+               ReferencedContainer = "container:CoreStore.xcodeproj">
+            </BuildableReference>
+         </TestableReference>
+      </Testables>
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "2F03A52F19C5C6DA005002A5"
+            BuildableName = "CoreStore.framework"
+            BlueprintName = "CoreStore iOS"
+            ReferencedContainer = "container:CoreStore.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
+      <AdditionalOptions>
+      </AdditionalOptions>
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      launchStyle = "0"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES">
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "B5D9E2ED1CA2C317007A9D52"
+            BuildableName = "CoreStore_iOS7.framework"
+            BlueprintName = "CoreStore iOS7"
+            ReferencedContainer = "container:CoreStore.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
+      <AdditionalOptions>
+      </AdditionalOptions>
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Release">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>

CoreStore.xcodeproj/xcshareddata/xcschemes/CoreStore tvOS.xcscheme

@@ -0,0 +1,99 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "0720"
+   version = "1.3">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "82BA18881C4BBCBA00A0916E"
+               BuildableName = "CoreStore.framework"
+               BlueprintName = "CoreStore tvOS"
+               ReferencedContainer = "container:CoreStore.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES">
+      <Testables>
+         <TestableReference
+            skipped = "NO">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "82BA18911C4BBCBA00A0916E"
+               BuildableName = "CoreStoreTests.xctest"
+               BlueprintName = "CoreStoreTests tvOS"
+               ReferencedContainer = "container:CoreStore.xcodeproj">
+            </BuildableReference>
+         </TestableReference>
+      </Testables>
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "82BA18881C4BBCBA00A0916E"
+            BuildableName = "CoreStore.framework"
+            BlueprintName = "CoreStore tvOS"
+            ReferencedContainer = "container:CoreStore.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
+      <AdditionalOptions>
+      </AdditionalOptions>
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      launchStyle = "0"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES">
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "82BA18881C4BBCBA00A0916E"
+            BuildableName = "CoreStore.framework"
+            BlueprintName = "CoreStore tvOS"
+            ReferencedContainer = "container:CoreStore.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
+      <AdditionalOptions>
+      </AdditionalOptions>
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "82BA18881C4BBCBA00A0916E"
+            BuildableName = "CoreStore.framework"
+            BlueprintName = "CoreStore tvOS"
+            ReferencedContainer = "container:CoreStore.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>

CoreStore.xcodeproj/xcshareddata/xcschemes/CoreStore watchOS.xcscheme

@@ -0,0 +1,80 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "0700"
+   version = "1.3">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "B563216E1BD65082006C9394"
+               BuildableName = "CoreStore.framework"
+               BlueprintName = "CoreStore watchOS"
+               ReferencedContainer = "container:CoreStore.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES">
+      <Testables>
+      </Testables>
+      <AdditionalOptions>
+      </AdditionalOptions>
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      launchStyle = "0"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES">
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "B563216E1BD65082006C9394"
+            BuildableName = "CoreStore.framework"
+            BlueprintName = "CoreStore watchOS"
+            ReferencedContainer = "container:CoreStore.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
+      <AdditionalOptions>
+      </AdditionalOptions>
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+      <MacroExpansion>
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "B563216E1BD65082006C9394"
+            BuildableName = "CoreStore.framework"
+            BlueprintName = "CoreStore watchOS"
+            ReferencedContainer = "container:CoreStore.xcodeproj">
+         </BuildableReference>
+      </MacroExpansion>
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>

CoreStore.xcworkspace/contents.xcworkspacedata

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Workspace
+   version = "1.0">
+   <FileRef
+      location = "group:CoreStore.xcodeproj">
+   </FileRef>
+   <FileRef
+      location = "group:CoreStoreDemo/CoreStoreDemo.xcodeproj">
+   </FileRef>
+   <FileRef
+      location = "group:Carthage/Checkouts/GCDKit/GCDKit.xcodeproj">
+   </FileRef>
+</Workspace>

CoreStore.xcworkspace/xcshareddata/CoreStore.xcscmblueprint

@@ -0,0 +1,30 @@
+{
+  "DVTSourceControlWorkspaceBlueprintPrimaryRemoteRepositoryKey" : "4B60F1BCB491FF717C56441AE7783C74F417BE48",
+  "DVTSourceControlWorkspaceBlueprintWorkingCopyRepositoryLocationsKey" : {
+
+  },
+  "DVTSourceControlWorkspaceBlueprintWorkingCopyStatesKey" : {
+    "8B2E522D57154DFA93A06982C36315ECBEA4FA97" : 0,
+    "4B60F1BCB491FF717C56441AE7783C74F417BE48" : 0
+  },
+  "DVTSourceControlWorkspaceBlueprintIdentifierKey" : "EBFDEFFE-8BA0-441A-862A-1DE28AA5CD21",
+  "DVTSourceControlWorkspaceBlueprintWorkingCopyPathsKey" : {
+    "8B2E522D57154DFA93A06982C36315ECBEA4FA97" : "CoreStore\/Carthage\/Checkouts\/GCDKit\/",
+    "4B60F1BCB491FF717C56441AE7783C74F417BE48" : "CoreStore\/"
+  },
+  "DVTSourceControlWorkspaceBlueprintNameKey" : "CoreStore",
+  "DVTSourceControlWorkspaceBlueprintVersion" : 204,
+  "DVTSourceControlWorkspaceBlueprintRelativePathToProjectKey" : "CoreStore.xcworkspace",
+  "DVTSourceControlWorkspaceBlueprintRemoteRepositoriesKey" : [
+    {
+      "DVTSourceControlWorkspaceBlueprintRemoteRepositoryURLKey" : "https:\/\/github.com\/JohnEstropia\/CoreStore",
+      "DVTSourceControlWorkspaceBlueprintRemoteRepositorySystemKey" : "com.apple.dt.Xcode.sourcecontrol.Git",
+      "DVTSourceControlWorkspaceBlueprintRemoteRepositoryIdentifierKey" : "4B60F1BCB491FF717C56441AE7783C74F417BE48"
+    },
+    {
+      "DVTSourceControlWorkspaceBlueprintRemoteRepositoryURLKey" : "https:\/\/github.com\/JohnEstropia\/GCDKit.git",
+      "DVTSourceControlWorkspaceBlueprintRemoteRepositorySystemKey" : "com.apple.dt.Xcode.sourcecontrol.Git",
+      "DVTSourceControlWorkspaceBlueprintRemoteRepositoryIdentifierKey" : "8B2E522D57154DFA93A06982C36315ECBEA4FA97"
+    }
+  ]
+}

CoreStore/Convenience Helpers/NSFetchedResultsController+Convenience.swift

@@ -0,0 +1,255 @@
+//
+//  NSManagedObject+Convenience.swift
+//  CoreStore
+//
+//  Copyright © 2015 John Rommel Estropia
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+//
+
+import Foundation
+import CoreData
+
+
+// MARK: - NSFetchedResultsController
+
+public extension NSFetchedResultsController {
+    
+    /**
+     Utility for creating an `NSFetchedResultsController` from a `DataStack`. This is useful when an `NSFetchedResultsController` is preferred over the overhead of `ListMonitor`s abstraction.
+     
+     - parameter dataStack: the `DataStack` to observe objects from
+     - parameter from: a `From` clause indicating the entity type
+     - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: an `NSFetchedResultsController` that observes a `DataStack`
+     */
+    @nonobjc
+    public static func createFor<T: NSManagedObject>(dataStack: DataStack, _ from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: FetchClause...) -> NSFetchedResultsController {
+        
+        return CoreStoreFetchedResultsController<T>(
+            context: dataStack.mainContext,
+            fetchRequest: CoreStoreFetchRequest(),
+            from: from,
+            sectionBy: sectionBy,
+            fetchClauses: fetchClauses
+        )
+    }
+    
+    /**
+     Utility for creating an `NSFetchedResultsController` from a `DataStack`. This is useful when an `NSFetchedResultsController` is preferred over the overhead of `ListMonitor`s abstraction.
+     
+     - parameter dataStack: the `DataStack` to observe objects from
+     - parameter from: a `From` clause indicating the entity type
+     - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: an `NSFetchedResultsController` that observes a `DataStack`
+     */
+    @nonobjc
+    public static func createFor<T: NSManagedObject>(dataStack: DataStack, _ from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: [FetchClause]) -> NSFetchedResultsController {
+        
+        return CoreStoreFetchedResultsController<T>(
+            context: dataStack.mainContext,
+            fetchRequest: CoreStoreFetchRequest(),
+            from: from,
+            sectionBy: sectionBy,
+            fetchClauses: fetchClauses
+        )
+    }
+    
+    /**
+     Utility for creating an `NSFetchedResultsController` from a `DataStack`. This is useful when an `NSFetchedResultsController` is preferred over the overhead of `ListMonitor`s abstraction.
+     
+     - parameter dataStack: the `DataStack` to observe objects from
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: an `NSFetchedResultsController` that observes a `DataStack`
+     */
+    @nonobjc
+    public static func createFor<T: NSManagedObject>(dataStack: DataStack, _ from: From<T>, _ fetchClauses: FetchClause...) -> NSFetchedResultsController {
+        
+        return CoreStoreFetchedResultsController<T>(
+            context: dataStack.mainContext,
+            fetchRequest: CoreStoreFetchRequest(),
+            from: from,
+            sectionBy: nil,
+            fetchClauses: fetchClauses
+        )
+    }
+    
+    /**
+     Utility for creating an `NSFetchedResultsController` from a `DataStack`. This is useful when an `NSFetchedResultsController` is preferred over the overhead of `ListMonitor`s abstraction.
+     
+     - parameter dataStack: the `DataStack` to observe objects from
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: an `NSFetchedResultsController` that observes a `DataStack`
+     */
+    @nonobjc
+    public static func createFor<T: NSManagedObject>(dataStack: DataStack, _ from: From<T>, _ fetchClauses: [FetchClause]) -> NSFetchedResultsController {
+        
+        return CoreStoreFetchedResultsController<T>(
+            context: dataStack.mainContext,
+            fetchRequest: CoreStoreFetchRequest(),
+            from: from,
+            sectionBy: nil,
+            fetchClauses: fetchClauses
+        )
+    }
+    
+    /**
+     Utility for creating an `NSFetchedResultsController` from an `UnsafeDataTransaction`. This is useful when an `NSFetchedResultsController` is preferred over the overhead of `ListMonitor`s abstraction.
+     
+     - parameter transaction: the `UnsafeDataTransaction` to observe objects from
+     - parameter from: a `From` clause indicating the entity type
+     - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: an `NSFetchedResultsController` that observes an `UnsafeDataTransaction`
+     */
+    @nonobjc
+    public static func createFor<T: NSManagedObject>(transaction: UnsafeDataTransaction, _ from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: FetchClause...) -> NSFetchedResultsController {
+        
+        return CoreStoreFetchedResultsController<T>(
+            context: transaction.context,
+            fetchRequest: CoreStoreFetchRequest(),
+            from: from,
+            sectionBy: sectionBy,
+            fetchClauses: fetchClauses
+        )
+    }
+    
+    /**
+     Utility for creating an `NSFetchedResultsController` from an `UnsafeDataTransaction`. This is useful when an `NSFetchedResultsController` is preferred over the overhead of `ListMonitor`s abstraction.
+     
+     - parameter transaction: the `UnsafeDataTransaction` to observe objects from
+     - parameter from: a `From` clause indicating the entity type
+     - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: an `NSFetchedResultsController` that observes an `UnsafeDataTransaction`
+     */
+    @nonobjc
+    public static func createFor<T: NSManagedObject>(transaction: UnsafeDataTransaction, _ from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: [FetchClause]) -> NSFetchedResultsController {
+        
+        return CoreStoreFetchedResultsController<T>(
+            context: transaction.context,
+            fetchRequest: CoreStoreFetchRequest(),
+            from: from,
+            sectionBy: sectionBy,
+            fetchClauses: fetchClauses
+        )
+    }
+    
+    /**
+     Utility for creating an `NSFetchedResultsController` from an `UnsafeDataTransaction`. This is useful when an `NSFetchedResultsController` is preferred over the overhead of `ListMonitor`s abstraction.
+     
+     - parameter transaction: the `UnsafeDataTransaction` to observe objects from
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: an `NSFetchedResultsController` that observes an `UnsafeDataTransaction`
+     */
+    @nonobjc
+    public static func createFor<T: NSManagedObject>(transaction: UnsafeDataTransaction, _ from: From<T>, _ fetchClauses: FetchClause...) -> NSFetchedResultsController {
+        
+        return CoreStoreFetchedResultsController<T>(
+            context: transaction.context,
+            fetchRequest: CoreStoreFetchRequest(),
+            from: from,
+            sectionBy: nil,
+            fetchClauses: fetchClauses
+        )
+    }
+    
+    /**
+     Utility for creating an `NSFetchedResultsController` from an `UnsafeDataTransaction`. This is useful when an `NSFetchedResultsController` is preferred over the overhead of `ListMonitor`s abstraction.
+     
+     - parameter transaction: the `UnsafeDataTransaction` to observe objects from
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     */
+    @nonobjc
+    public static func createFor<T: NSManagedObject>(transaction: UnsafeDataTransaction, _ from: From<T>, _ fetchClauses: [FetchClause]) -> NSFetchedResultsController {
+        
+        return CoreStoreFetchedResultsController<T>(
+            context: transaction.context,
+            fetchRequest: CoreStoreFetchRequest(),
+            from: from,
+            sectionBy: nil,
+            fetchClauses: fetchClauses
+        )
+    }
+    
+    @available(*, deprecated=1.6.8, message="Use NSFetchedResultsController.createFor(_:_:_:_:)  instead.")
+    @nonobjc
+    public static func createForStack<T: NSManagedObject>(dataStack: DataStack, fetchRequest: NSFetchRequest, from: From<T>? = nil, sectionBy: SectionBy? = nil, fetchClauses: [FetchClause]) -> NSFetchedResultsController {
+        
+        return CoreStoreFetchedResultsController<T>(
+            context: dataStack.mainContext,
+            fetchRequest: fetchRequest,
+            from: from,
+            sectionBy: sectionBy,
+            fetchClauses: fetchClauses
+        )
+    }
+    
+    @available(*, deprecated=1.5.2, message="Use NSFetchedResultsController.createFor(_:_:_:_:) to create NSFetchedResultsControllers directly")
+    @nonobjc
+    public convenience init<T: NSManagedObject>(dataStack: DataStack, fetchRequest: NSFetchRequest, from: From<T>? = nil, sectionBy: SectionBy? = nil, fetchClauses: [FetchClause]) {
+        
+        let context = dataStack.mainContext
+        from?.applyToFetchRequest(fetchRequest, context: context, applyAffectedStores: false)
+        for clause in fetchClauses {
+            
+            clause.applyToFetchRequest(fetchRequest)
+        }
+        
+        if let from = from {
+            
+            from.applyAffectedStoresForFetchedRequest(fetchRequest, context: context)
+        }
+        else {
+            
+            guard let from = (fetchRequest.entity.flatMap { $0.managedObjectClassName }).flatMap(NSClassFromString).flatMap(From.init) else {
+                
+                fatalError("Attempted to create an \(typeName(NSFetchedResultsController)) without a  From clause or an NSEntityDescription.")
+            }
+            from.applyAffectedStoresForFetchedRequest(fetchRequest, context: context)
+        }
+        
+        self.init(
+            fetchRequest: fetchRequest,
+            managedObjectContext: context,
+            sectionNameKeyPath: sectionBy?.sectionKeyPath,
+            cacheName: nil
+        )
+    }
+    
+    
+    // MARK: Internal
+    
+    internal static func createFromContext<T: NSManagedObject>(context: NSManagedObjectContext, fetchRequest: NSFetchRequest, from: From<T>? = nil, sectionBy: SectionBy? = nil, fetchClauses: [FetchClause]) -> NSFetchedResultsController {
+        
+        return CoreStoreFetchedResultsController<T>(
+            context: context,
+            fetchRequest: fetchRequest,
+            from: from,
+            sectionBy: sectionBy,
+            fetchClauses: fetchClauses
+        )
+    }
+}

CoreStore/Convenience Helpers/NSManagedObject+Convenience.swift

@@ -2,7 +2,7 @@
 //  NSManagedObject+Convenience.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -32,11 +32,12 @@ import CoreData
 public extension NSManagedObject {
     
     /**
-    Provides a convenience wrapper for accessing `primitiveValueForKey(...)` with proper calls to `willAccessValueForKey(...)` and `didAccessValueForKey(...)`. This is useful when implementing accessor methods for transient attributes.
-    
-    - parameter KVCKey: the KVC key
-    - returns: the primitive value for the KVC key
-    */
+     Provides a convenience wrapper for accessing `primitiveValueForKey(...)` with proper calls to `willAccessValueForKey(...)` and `didAccessValueForKey(...)`. This is useful when implementing accessor methods for transient attributes.
+     
+     - parameter KVCKey: the KVC key
+     - returns: the primitive value for the KVC key
+     */
+    @warn_unused_result
     public func accessValueForKVCKey(KVCKey: KeyPath) -> AnyObject? {
         
         self.willAccessValueForKey(KVCKey)
@@ -47,15 +48,31 @@ public extension NSManagedObject {
     }
     
     /**
-    Provides a convenience wrapper for setting `setPrimitiveValue(...)` with proper calls to `willChangeValueForKey(...)` and `didChangeValueForKey(...)`. This is useful when implementing mutator methods for transient attributes.
-    
-    - parameter value: the value to set the KVC key with
-    - parameter KVCKey: the KVC key
-    */
+     Provides a convenience wrapper for setting `setPrimitiveValue(...)` with proper calls to `willChangeValueForKey(...)` and `didChangeValueForKey(...)`. This is useful when implementing mutator methods for transient attributes.
+     
+     - parameter value: the value to set the KVC key with
+     - parameter KVCKey: the KVC key
+     */
     public func setValue(value: AnyObject?, forKVCKey KVCKey: KeyPath) {
         
         self.willChangeValueForKey(KVCKey)
         self.setPrimitiveValue(value, forKey: KVCKey)
         self.didChangeValueForKey(KVCKey)
     }
+    
+    /**
+     Re-faults the object to use the latest values from the persistent store
+     */
+    public func refreshAsFault() {
+        
+        self.managedObjectContext?.refreshObject(self, mergeChanges: false)
+    }
+    
+    /**
+     Re-faults the object to use the latest values from the persistent store and merges previously pending changes back
+     */
+    public func refreshAndMerge() {
+        
+        self.managedObjectContext?.refreshObject(self, mergeChanges: true)
+    }
 }

CoreStore/Convenience Helpers/NSProgress+Convenience.swift

@@ -2,7 +2,7 @@
 //  NSProgress+Convenience.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -24,19 +24,19 @@
 //
 
 import Foundation
-import GCDKit
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
 
 
 // MARK: - NSProgress
 
 public extension NSProgress {
     
-    // MARK: Public
-    
     /**
-    Sets a closure that the `NSProgress` calls whenever its `fractionCompleted` changes. You can use this instead of setting up KVO.
-    - parameter closure: the closure to execute on progress change
-    */
+     Sets a closure that the `NSProgress` calls whenever its `fractionCompleted` changes. You can use this instead of setting up KVO.
+     - parameter closure: the closure to execute on progress change
+     */
     public func setProgressHandler(closure: ((progress: NSProgress) -> Void)?) {
         
         self.progressObserver.progressHandler = closure

CoreStore/CoreStore.h

@@ -2,7 +2,7 @@
 //  CoreStore.h
 //  CoreStore
 //
-//  Copyright (c) 2014 John Rommel Estropia
+//  Copyright © 2014 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -23,8 +23,8 @@
 //  SOFTWARE.
 //
 
+#import <Foundation/Foundation.h>
 #import <CoreData/CoreData.h>
 
 FOUNDATION_EXPORT double CoreStoreVersionNumber;
 FOUNDATION_EXPORT const unsigned char CoreStoreVersionString[];
-

CoreStore/CoreStore.swift

@@ -2,7 +2,7 @@
 //  CoreStore.swift
 //  CoreStore
 //
-//  Copyright (c) 2014 John Rommel Estropia
+//  Copyright © 2014 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -24,23 +24,23 @@
 //
 
 import CoreData
-import GCDKit
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
 
 
 // MARK: - CoreStore
 
 /**
-`CoreStore` is the main entry point for all other APIs.
-*/
+ `CoreStore` is the main entry point for all other APIs.
+ */
 public enum CoreStore {
     
-    // MARK: Public
-    
     /**
-    The default `DataStack` instance to be used. If `defaultStack` is not set before the first time accessed, a default-configured `DataStack` will be created.
-    
-    Changing the `defaultStack` is thread safe, but it is recommended to setup `DataStacks` on a common queue (e.g. the main queue).
-    */
+     The default `DataStack` instance to be used. If `defaultStack` is not set before the first time accessed, a default-configured `DataStack` will be created.
+     
+     Changing the `defaultStack` is thread safe, but it is recommended to setup `DataStacks` on a common queue (e.g. the main queue).
+     */
     public static var defaultStack: DataStack {
         
         get {

CoreStore/Fetching and Querying/BaseDataTransaction+Querying.swift

@@ -2,7 +2,7 @@
 //  BaseDataTransaction+Querying.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -31,19 +31,80 @@ import CoreData
 
 public extension BaseDataTransaction {
     
-    // MARK: Public
+    /**
+     Fetches the `NSManagedObject` instance in the transaction's context from a reference created from a transaction or from a different managed object context.
+     
+     - parameter object: a reference to the object created/fetched outside the transaction
+     - returns: the `NSManagedObject` instance if the object exists in the transaction, or `nil` if not found.
+     */
+    @warn_unused_result
+    public func fetchExisting<T: NSManagedObject>(object: T) -> T? {
+        
+        do {
+            
+            return (try self.context.existingObjectWithID(object.objectID) as! T)
+        }
+        catch _ {
+            
+            return nil
+        }
+    }
     
     /**
-    Fetches the first `NSManagedObject` instance that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     Fetches the `NSManagedObject` instance in the transaction's context from an `NSManagedObjectID`.
+     
+     - parameter objectID: the `NSManagedObjectID` for the object
+     - returns: the `NSManagedObject` instance if the object exists in the transaction, or `nil` if not found.
+     */
+    @warn_unused_result
+    public func fetchExisting<T: NSManagedObject>(objectID: NSManagedObjectID) -> T? {
+        
+        do {
+            
+            return (try self.context.existingObjectWithID(objectID) as! T)
+        }
+        catch _ {
+            
+            return nil
+        }
+    }
     
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the first `NSManagedObject` instance that satisfies the specified `FetchClause`s
-    */
+    /**
+     Fetches the `NSManagedObject` instances in the transaction's context from references created from a transaction or from a different managed object context.
+     
+     - parameter objects: an array of `NSManagedObject`s created/fetched outside the transaction
+     - returns: the `NSManagedObject` array for objects that exists in the transaction
+     */
+    @warn_unused_result
+    public func fetchExisting<T: NSManagedObject, S: SequenceType where S.Generator.Element == T>(objects: S) -> [T] {
+        
+        return objects.flatMap { (try? self.context.existingObjectWithID($0.objectID)) as? T }
+    }
+    
+    /**
+     Fetches the `NSManagedObject` instances in the transaction's context from a list of `NSManagedObjectID`.
+     
+     - parameter objectIDs: the `NSManagedObjectID` array for the objects
+     - returns: the `NSManagedObject` array for objects that exists in the transaction
+     */
+    @warn_unused_result
+    public func fetchExisting<T: NSManagedObject, S: SequenceType where S.Generator.Element == NSManagedObjectID>(objectIDs: S) -> [T] {
+        
+        return objectIDs.flatMap { (try? self.context.existingObjectWithID($0)) as? T }
+    }
+    
+    /**
+     Fetches the first `NSManagedObject` instance that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the first `NSManagedObject` instance that satisfies the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchOne<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> T? {
         
         CoreStore.assert(
-            self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to fetch from a \(typeName(self)) outside its designated queue."
         )
         
@@ -51,16 +112,17 @@ public extension BaseDataTransaction {
     }
     
     /**
-    Fetches the first `NSManagedObject` instance that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the first `NSManagedObject` instance that satisfies the specified `FetchClause`s
-    */
+     Fetches the first `NSManagedObject` instance that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the first `NSManagedObject` instance that satisfies the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchOne<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> T? {
         
         CoreStore.assert(
-            self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to fetch from a \(typeName(self)) outside its designated queue."
         )
         
@@ -68,16 +130,17 @@ public extension BaseDataTransaction {
     }
     
     /**
-    Fetches all `NSManagedObject` instances that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: all `NSManagedObject` instances that satisfy the specified `FetchClause`s
-    */
+     Fetches all `NSManagedObject` instances that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: all `NSManagedObject` instances that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchAll<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> [T]? {
         
         CoreStore.assert(
-            self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to fetch from a \(typeName(self)) outside its designated queue."
         )
         
@@ -85,16 +148,17 @@ public extension BaseDataTransaction {
     }
     
     /**
-    Fetches all `NSManagedObject` instances that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: all `NSManagedObject` instances that satisfy the specified `FetchClause`s
-    */
+     Fetches all `NSManagedObject` instances that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: all `NSManagedObject` instances that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchAll<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> [T]? {
         
         CoreStore.assert(
-            self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to fetch from a \(typeName(self)) outside its designated queue."
         )
         
@@ -102,16 +166,17 @@ public extension BaseDataTransaction {
     }
     
     /**
-    Fetches the number of `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the number `NSManagedObject`s that satisfy the specified `FetchClause`s
-    */
+     Fetches the number of `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the number `NSManagedObject`s that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchCount<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> Int? {
         
         CoreStore.assert(
-            self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to fetch from a \(typeName(self)) outside its designated queue."
         )
         
@@ -119,16 +184,17 @@ public extension BaseDataTransaction {
     }
     
     /**
-    Fetches the number of `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the number `NSManagedObject`s that satisfy the specified `FetchClause`s
-    */
+     Fetches the number of `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the number `NSManagedObject`s that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchCount<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> Int? {
         
         CoreStore.assert(
-            self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to fetch from a \(typeName(self)) outside its designated queue."
         )
         
@@ -136,16 +202,17 @@ public extension BaseDataTransaction {
     }
     
     /**
-    Fetches the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s
-    */
+     Fetches the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchObjectID<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> NSManagedObjectID? {
         
         CoreStore.assert(
-            self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to fetch from a \(typeName(self)) outside its designated queue."
         )
         
@@ -153,16 +220,17 @@ public extension BaseDataTransaction {
     }
     
     /**
-    Fetches the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s
-    */
+     Fetches the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchObjectID<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> NSManagedObjectID? {
         
         CoreStore.assert(
-            self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to fetch from a \(typeName(self)) outside its designated queue."
         )
         
@@ -170,16 +238,17 @@ public extension BaseDataTransaction {
     }
     
     /**
-    Fetches the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s
-    */
+     Fetches the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchObjectIDs<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> [NSManagedObjectID]? {
         
         CoreStore.assert(
-            self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to fetch from a \(typeName(self)) outside its designated queue."
         )
         
@@ -187,16 +256,17 @@ public extension BaseDataTransaction {
     }
     
     /**
-    Fetches the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s
-    */
+     Fetches the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchObjectIDs<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> [NSManagedObjectID]? {
         
         CoreStore.assert(
-            self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to fetch from a \(typeName(self)) outside its designated queue."
         )
         
@@ -204,16 +274,16 @@ public extension BaseDataTransaction {
     }
     
     /**
-    Deletes all `NSManagedObject`s that satisfy the specified `DeleteClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter deleteClauses: a series of `DeleteClause` instances for the delete request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the number of `NSManagedObject`s deleted
-    */
+     Deletes all `NSManagedObject`s that satisfy the specified `DeleteClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter deleteClauses: a series of `DeleteClause` instances for the delete request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the number of `NSManagedObject`s deleted
+     */
     public func deleteAll<T: NSManagedObject>(from: From<T>, _ deleteClauses: DeleteClause...) -> Int? {
         
         CoreStore.assert(
-            self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to delete from a \(typeName(self)) outside its designated queue."
         )
         
@@ -221,16 +291,16 @@ public extension BaseDataTransaction {
     }
     
     /**
-    Deletes all `NSManagedObject`s that satisfy the specified `DeleteClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter deleteClauses: a series of `DeleteClause` instances for the delete request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the number of `NSManagedObject`s deleted
-    */
+     Deletes all `NSManagedObject`s that satisfy the specified `DeleteClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter deleteClauses: a series of `DeleteClause` instances for the delete request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the number of `NSManagedObject`s deleted
+     */
     public func deleteAll<T: NSManagedObject>(from: From<T>, _ deleteClauses: [DeleteClause]) -> Int? {
         
         CoreStore.assert(
-            self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to delete from a \(typeName(self)) outside its designated queue."
         )
         
@@ -238,19 +308,20 @@ public extension BaseDataTransaction {
     }
     
     /**
-    Queries aggregate values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    
-    A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
-    - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
-    */
+     Queries aggregate values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     
+     A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
+     - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
+     */
+    @warn_unused_result
     public func queryValue<T: NSManagedObject, U: SelectValueResultType>(from: From<T>, _ selectClause: Select<U>, _ queryClauses: QueryClause...) -> U? {
         
         CoreStore.assert(
-            self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to query from a \(typeName(self)) outside its designated queue."
         )
         
@@ -258,19 +329,20 @@ public extension BaseDataTransaction {
     }
     
     /**
-    Queries aggregate values or aggregates as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    
-    A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
-    - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
-    */
+     Queries aggregate values or aggregates as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     
+     A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
+     - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
+     */
+    @warn_unused_result
     public func queryValue<T: NSManagedObject, U: SelectValueResultType>(from: From<T>, _ selectClause: Select<U>, _ queryClauses: [QueryClause]) -> U? {
         
         CoreStore.assert(
-            self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to query from a \(typeName(self)) outside its designated queue."
         )
         
@@ -278,19 +350,20 @@ public extension BaseDataTransaction {
     }
     
     /**
-    Queries a dictionary of attribute values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    
-    A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
-    - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
-    */
+     Queries a dictionary of attribute values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     
+     A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
+     - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
+     */
+    @warn_unused_result
     public func queryAttributes<T: NSManagedObject>(from: From<T>, _ selectClause: Select<NSDictionary>, _ queryClauses: QueryClause...) -> [[NSString: AnyObject]]? {
         
         CoreStore.assert(
-            self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to query from a \(typeName(self)) outside its designated queue."
         )
         
@@ -298,19 +371,20 @@ public extension BaseDataTransaction {
     }
     
     /**
-    Queries a dictionary of attribute values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    
-    A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
-    - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
-    */
+     Queries a dictionary of attribute values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     
+     A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
+     - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
+     */
+    @warn_unused_result
     public func queryAttributes<T: NSManagedObject>(from: From<T>, _ selectClause: Select<NSDictionary>, _ queryClauses: [QueryClause]) -> [[NSString: AnyObject]]? {
         
         CoreStore.assert(
-            self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to query from a \(typeName(self)) outside its designated queue."
         )
         

CoreStore/Fetching and Querying/Concrete Clauses/From.swift

@@ -2,7 +2,7 @@
 //  From.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -30,115 +30,269 @@ import CoreData
 // MARK: - From
 
 /**
-A `Form` clause binds the `NSManagedObject` entity type to the generics type system.
-*/
+ A `From` clause specifies the source entity and source persistent store for fetch and query methods. A common usage is to just indicate the entity:
+ ```
+ let person = transaction.fetchOne(From(MyPersonEntity))
+ ```
+ For cases where multiple `NSPersistentStore`s contain the same entity, the source configuration's name needs to be specified as well:
+ ```
+ let person = transaction.fetchOne(From<MyPersonEntity>("Configuration1"))
+ ```
+ */
 public struct From<T: NSManagedObject> {
     
-    // MARK: Public
-    
+    /**
+     Initializes a `From` clause.
+     Sample Usage:
+     ```
+     let people = transaction.fetchAll(From<MyPersonEntity>())
+     ```
+     */
     public init(){
         
-        self.entityClass = T.self
-        self.findPersistentStores = { _ in nil }
+        self.init(entityClass: T.self)
     }
     
+    /**
+     Initializes a `From` clause with the specified entity type.
+     Sample Usage:
+     ```
+     let people = transaction.fetchAll(From<MyPersonEntity>())
+     ```
+     - parameter entity: the `NSManagedObject` type to be created
+     */
     public init(_ entity: T.Type) {
         
-        self.entityClass = entity
-        self.findPersistentStores = { _ in nil }
+        self.init(entityClass: entity)
     }
     
+    /**
+     Initializes a `From` clause with the specified entity class.
+     Sample Usage:
+     ```
+     let people = transaction.fetchAll(From<MyPersonEntity>())
+     ```
+     - parameter entityClass: the `NSManagedObject` class type to be created
+     */
     public init(_ entityClass: AnyClass) {
         
-        self.entityClass = entityClass
-        self.findPersistentStores = { _ in nil }
+        self.init(entityClass: entityClass)
     }
     
-    public init(_ configurations: String?...) {
+    /**
+     Initializes a `From` clause with the specified configurations.
+     Sample Usage:
+     ```
+     let people = transaction.fetchAll(From<MyPersonEntity>(nil, "Configuration1"))
+     ```
+     - parameter configuration: the `NSPersistentStore` configuration name to associate objects from. This parameter is required if multiple configurations contain the created `NSManagedObject`'s entity type. Set to `nil` to use the default configuration.
+     - parameter otherConfigurations: an optional list of other configuration names to associate objects from (see `configuration` parameter)
+     */
+    public init(_ configuration: String?, otherConfigurations: String?...) {
         
-        self.init(entityClass: T.self, configurations: configurations)
+        self.init(entityClass: T.self, configurations: [configuration] + otherConfigurations)
     }
     
+    /**
+     Initializes a `From` clause with the specified configurations.
+     Sample Usage:
+     ```
+     let people = transaction.fetchAll(From<MyPersonEntity>(["Configuration1", "Configuration2"]))
+     ```
+     - parameter configurations: a list of `NSPersistentStore` configuration names to associate objects from. This parameter is required if multiple configurations contain the created `NSManagedObject`'s entity type. Set to `nil` to use the default configuration.
+     */
     public init(_ configurations: [String?]) {
         
         self.init(entityClass: T.self, configurations: configurations)
     }
     
-    public init(_ entity: T.Type, _ configurations: String?...) {
+    /**
+     Initializes a `From` clause with the specified configurations.
+     Sample Usage:
+     ```
+     let people = transaction.fetchAll(From(MyPersonEntity.self, nil, "Configuration1"))
+     ```
+     - parameter entity: the associated `NSManagedObject` type
+     - parameter configuration: the `NSPersistentStore` configuration name to associate objects from. This parameter is required if multiple configurations contain the created `NSManagedObject`'s entity type. Set to `nil` to use the default configuration.
+     - parameter otherConfigurations: an optional list of other configuration names to associate objects from (see `configuration` parameter)
+     */
+    public init(_ entity: T.Type, _ configuration: String?, _ otherConfigurations: String?...) {
         
-        self.init(entityClass: entity, configurations: configurations)
+        self.init(entityClass: entity, configurations: [configuration] + otherConfigurations)
     }
     
+    /**
+     Initializes a `From` clause with the specified configurations.
+     Sample Usage:
+     ```
+     let people = transaction.fetchAll(From(MyPersonEntity.self, ["Configuration1", "Configuration1"]))
+     ```
+     - parameter entity: the associated `NSManagedObject` type
+     - parameter configurations: a list of `NSPersistentStore` configuration names to associate objects from. This parameter is required if multiple configurations contain the created `NSManagedObject`'s entity type. Set to `nil` to use the default configuration.
+     */
     public init(_ entity: T.Type, _ configurations: [String?]) {
         
         self.init(entityClass: entity, configurations: configurations)
     }
     
-    public init(_ entityClass: AnyClass, _ configurations: String?...) {
+    /**
+     Initializes a `From` clause with the specified configurations.
+     Sample Usage:
+     ```
+     let people = transaction.fetchAll(From(MyPersonEntity.self, nil, "Configuration1"))
+     ```
+     - parameter entity: the associated `NSManagedObject` entity class
+     - parameter configuration: the `NSPersistentStore` configuration name to associate objects from. This parameter is required if multiple configurations contain the created `NSManagedObject`'s entity type. Set to `nil` to use the default configuration.
+     - parameter otherConfigurations: an optional list of other configuration names to associate objects from (see `configuration` parameter)
+     */
+    public init(_ entityClass: AnyClass, _ configuration: String?, _ otherConfigurations: String?...) {
         
-        self.init(entityClass: entityClass, configurations: configurations)
+        self.init(entityClass: entityClass, configurations: [configuration] + otherConfigurations)
     }
     
+    /**
+     Initializes a `From` clause with the specified configurations.
+     Sample Usage:
+     ```
+     let people = transaction.fetchAll(From(MyPersonEntity.self, ["Configuration1", "Configuration1"]))
+     ```
+     - parameter entity: the associated `NSManagedObject` entity class
+     - parameter configurations: a list of `NSPersistentStore` configuration names to associate objects from. This parameter is required if multiple configurations contain the created `NSManagedObject`'s entity type. Set to `nil` to use the default configuration.
+     */
     public init(_ entityClass: AnyClass, _ configurations: [String?]) {
         
         self.init(entityClass: entityClass, configurations: configurations)
     }
     
-    public init(_ storeURLs: NSURL...) {
+    /**
+     Initializes a `From` clause with the specified store URLs.
+     
+     - parameter storeURL: the persistent store URL to associate objects from.
+     - parameter otherStoreURLs: an optional list of other persistent store URLs to associate objects from (see `storeURL` parameter)
+     */
+    public init(_ storeURL: NSURL, _ otherStoreURLs: NSURL...) {
         
-        self.init(entityClass: T.self, storeURLs: storeURLs)
+        self.init(entityClass: T.self, storeURLs: [storeURL] + otherStoreURLs)
     }
     
+    /**
+     Initializes a `From` clause with the specified store URLs.
+     
+     - parameter storeURLs: the persistent store URLs to associate objects from.
+     */
     public init(_ storeURLs: [NSURL]) {
         
         self.init(entityClass: T.self, storeURLs: storeURLs)
     }
     
-    public init(_ entity: T.Type, _ storeURLs: NSURL...) {
+    /**
+     Initializes a `From` clause with the specified store URLs.
+     
+     - parameter entity: the associated `NSManagedObject` type
+     - parameter storeURL: the persistent store URL to associate objects from.
+     - parameter otherStoreURLs: an optional list of other persistent store URLs to associate objects from (see `storeURL` parameter)
+     */
+    public init(_ entity: T.Type, _ storeURL: NSURL, _ otherStoreURLs: NSURL...) {
         
-        self.init(entityClass: entity, storeURLs: storeURLs)
+        self.init(entityClass: entity, storeURLs: [storeURL] + otherStoreURLs)
     }
     
+    /**
+     Initializes a `From` clause with the specified store URLs.
+     
+     - parameter entity: the associated `NSManagedObject` type
+     - parameter storeURLs: the persistent store URLs to associate objects from.
+     */
     public init(_ entity: T.Type, _ storeURLs: [NSURL]) {
         
         self.init(entityClass: entity, storeURLs: storeURLs)
     }
     
-    public init(_ entityClass: AnyClass, _ storeURLs: NSURL...) {
+    /**
+     Initializes a `From` clause with the specified store URLs.
+     
+     - parameter entity: the associated `NSManagedObject` entity class
+     - parameter storeURL: the persistent store URL to associate objects from.
+     - parameter otherStoreURLs: an optional list of other persistent store URLs to associate objects from (see `storeURL` parameter)
+     */
+    public init(_ entityClass: AnyClass, _ storeURL: NSURL, _ otherStoreURLs: NSURL...) {
         
-        self.init(entityClass: entityClass, storeURLs: storeURLs)
+        self.init(entityClass: entityClass, storeURLs: [storeURL] + otherStoreURLs)
     }
     
+    /**
+     Initializes a `From` clause with the specified store URLs.
+     
+     - parameter entity: the associated `NSManagedObject` entity class
+     - parameter storeURLs: the persistent store URLs to associate objects from.
+     */
     public init(_ entityClass: AnyClass, _ storeURLs: [NSURL]) {
         
         self.init(entityClass: entityClass, storeURLs: storeURLs)
     }
     
-    public init(_ persistentStores: NSPersistentStore...) {
+    /**
+     Initializes a `From` clause with the specified `NSPersistentStore`s.
+     
+     - parameter persistentStore: the `NSPersistentStore` to associate objects from.
+     - parameter otherPersistentStores: an optional list of other `NSPersistentStore`s to associate objects from (see `persistentStore` parameter)
+     */
+    public init(_ persistentStore: NSPersistentStore, _ otherPersistentStores: NSPersistentStore...) {
         
-        self.init(entityClass: T.self, persistentStores: persistentStores)
+        self.init(entityClass: T.self, persistentStores: [persistentStore] + otherPersistentStores)
     }
     
+    /**
+     Initializes a `From` clause with the specified `NSPersistentStore`s.
+     
+     - parameter persistentStores: the `NSPersistentStore`s to associate objects from.
+     */
     public init(_ persistentStores: [NSPersistentStore]) {
         
         self.init(entityClass: T.self, persistentStores: persistentStores)
     }
     
-    public init(_ entity: T.Type, _ persistentStores: NSPersistentStore...) {
+    /**
+     Initializes a `From` clause with the specified `NSPersistentStore`s.
+     
+     - parameter entity: the associated `NSManagedObject` type
+     - parameter persistentStore: the `NSPersistentStore` to associate objects from.
+     - parameter otherPersistentStores: an optional list of other `NSPersistentStore`s to associate objects from (see `persistentStore` parameter)
+     */
+    public init(_ entity: T.Type, _ persistentStore: NSPersistentStore, _ otherPersistentStores: NSPersistentStore...) {
         
-        self.init(entityClass: entity, persistentStores: persistentStores)
+        self.init(entityClass: entity, persistentStores: [persistentStore] + otherPersistentStores)
     }
     
+    /**
+     Initializes a `From` clause with the specified `NSPersistentStore`s.
+     
+     - parameter entity: the associated `NSManagedObject` type
+     - parameter persistentStores: the `NSPersistentStore`s to associate objects from.
+     */
     public init(_ entity: T.Type, _ persistentStores: [NSPersistentStore]) {
         
         self.init(entityClass: entity, persistentStores: persistentStores)
     }
     
-    public init(_ entityClass: AnyClass, _ persistentStores: NSPersistentStore...) {
+    /**
+     Initializes a `From` clause with the specified `NSPersistentStore`s.
+     
+     - parameter entity: the associated `NSManagedObject` entity class
+     - parameter persistentStore: the `NSPersistentStore` to associate objects from.
+     - parameter otherPersistentStores: an optional list of other `NSPersistentStore`s to associate objects from (see `persistentStore` parameter)
+     */
+    public init(_ entityClass: AnyClass, _ persistentStore: NSPersistentStore, _ otherPersistentStores: NSPersistentStore...) {
         
-        self.init(entityClass: entityClass, persistentStores: persistentStores)
+        self.init(entityClass: entityClass, persistentStores: [persistentStore] + otherPersistentStores)
     }
     
+    /**
+     Initializes a `From` clause with the specified `NSPersistentStore`s.
+     
+     - parameter entity: the associated `NSManagedObject` entity class
+     - parameter persistentStores: the `NSPersistentStore`s to associate objects from.
+     */
     public init(_ entityClass: AnyClass, _ persistentStores: [NSPersistentStore]) {
         
         self.init(entityClass: entityClass, persistentStores: persistentStores)
@@ -147,10 +301,20 @@ public struct From<T: NSManagedObject> {
     
     // MARK: Internal
     
-    internal func applyToFetchRequest(fetchRequest: NSFetchRequest, context: NSManagedObjectContext) {
+    internal func applyToFetchRequest(fetchRequest: NSFetchRequest, context: NSManagedObjectContext, applyAffectedStores: Bool = true) {
         
         fetchRequest.entity = context.entityDescriptionForEntityClass(self.entityClass)
-        fetchRequest.affectedStores = self.findPersistentStores(context: context)
+        if applyAffectedStores {
+            
+            self.applyAffectedStoresForFetchedRequest(fetchRequest, context: context)
+        }
+    }
+    
+    internal func applyAffectedStoresForFetchedRequest(fetchRequest: NSFetchRequest, context: NSManagedObjectContext) -> Bool {
+        
+        let stores = self.findPersistentStores(context: context)
+        fetchRequest.affectedStores = stores
+        return stores?.isEmpty == false
     }
     
     
@@ -160,6 +324,15 @@ public struct From<T: NSManagedObject> {
     
     private let findPersistentStores: (context: NSManagedObjectContext) -> [NSPersistentStore]?
     
+    private init(entityClass: AnyClass) {
+        
+        self.entityClass = entityClass
+        self.findPersistentStores = { (context: NSManagedObjectContext) -> [NSPersistentStore]? in
+            
+            return context.parentStack?.persistentStoresForEntityClass(entityClass)
+        }
+    }
+    
     private init(entityClass: AnyClass, configurations: [String?]) {
         
         let configurationsSet = Set(configurations.map { $0 ?? Into.defaultConfigurationName })

CoreStore/Fetching and Querying/Concrete Clauses/GroupBy.swift

@@ -2,7 +2,7 @@
 //  GroupBy.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -30,36 +30,34 @@ import CoreData
 // MARK: - GroupBy
 
 /**
-The `GroupBy` clause specifies that the result of a query be grouped accoording to the specified key path.
-*/
+ The `GroupBy` clause specifies that the result of a query be grouped accoording to the specified key path.
+ */
 public struct GroupBy: QueryClause {
     
-    // MARK: Public
-    
     /**
-    Initializes a `GroupBy` clause with a list of key path strings
-    
-    - parameter keyPaths: a list of key path strings to group results with
-    */
+     Initializes a `GroupBy` clause with a list of key path strings
+     
+     - parameter keyPaths: a list of key path strings to group results with
+     */
     public init(_ keyPaths: [KeyPath]) {
         
         self.keyPaths = keyPaths
     }
     
     /**
-    Initializes a `GroupBy` clause with an empty list of key path strings
-    */
+     Initializes a `GroupBy` clause with an empty list of key path strings
+     */
     public init() {
         
         self.init([])
     }
     
     /**
-    Initializes a `GroupBy` clause with a list of key path strings
-    
-    - parameter keyPath: a key path string to group results with
-    - parameter keyPaths: a series of key path strings to group results with
-    */
+     Initializes a `GroupBy` clause with a list of key path strings
+     
+     - parameter keyPath: a key path string to group results with
+     - parameter keyPaths: a series of key path strings to group results with
+     */
     public init(_ keyPath: KeyPath, _ keyPaths: KeyPath...) {
         
         self.init([keyPath] + keyPaths)
@@ -72,7 +70,7 @@ public struct GroupBy: QueryClause {
     
     public func applyToFetchRequest(fetchRequest: NSFetchRequest) {
         
-        if fetchRequest.propertiesToGroupBy != nil {
+        if let keyPaths = fetchRequest.propertiesToGroupBy as? [String] where keyPaths != self.keyPaths {
             
             CoreStore.log(
                 .Warning,

CoreStore/Fetching and Querying/Concrete Clauses/OrderBy.swift

@@ -2,7 +2,7 @@
 //  OrderBy.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -24,6 +24,7 @@
 //
 
 import Foundation
+import CoreData
 
 
 public func +(left: OrderBy, right: OrderBy) -> OrderBy {
@@ -45,18 +46,18 @@ public typealias KeyPath = String
 // MARK: - SortKey
 
 /**
-The `SortKey` is passed to the `OrderBy` clause to indicate the sort keys and their sort direction.
-*/
+ The `SortKey` is passed to the `OrderBy` clause to indicate the sort keys and their sort direction.
+ */
 public enum SortKey {
     
     /**
-    Indicates that the `KeyPath` should be sorted in ascending order
-    */
+     Indicates that the `KeyPath` should be sorted in ascending order
+     */
     case Ascending(KeyPath)
     
     /**
-    Indicates that the `KeyPath` should be sorted in descending order
-    */
+     Indicates that the `KeyPath` should be sorted in descending order
+     */
     case Descending(KeyPath)
 }
 
@@ -64,45 +65,43 @@ public enum SortKey {
 // MARK: - OrderBy
 
 /**
-The `OrderBy` clause specifies the sort order for results for a fetch or a query.
-*/
+ The `OrderBy` clause specifies the sort order for results for a fetch or a query.
+ */
 public struct OrderBy: FetchClause, QueryClause, DeleteClause {
     
-    // MARK: Public
-    
     /**
-    Initializes a `OrderBy` clause with a list of sort descriptors
-    
-    - parameter sortDescriptors: a series of `NSSortDescriptor`s
-    */
+     Initializes a `OrderBy` clause with a list of sort descriptors
+     
+     - parameter sortDescriptors: a series of `NSSortDescriptor`s
+     */
     public init(_ sortDescriptors: [NSSortDescriptor]) {
         
         self.sortDescriptors = sortDescriptors
     }
     
     /**
-    Initializes a `OrderBy` clause with an empty list of sort descriptors
-    */
+     Initializes a `OrderBy` clause with an empty list of sort descriptors
+     */
     public init() {
         
         self.init([NSSortDescriptor]())
     }
     
     /**
-    Initializes a `OrderBy` clause with a single sort descriptor
-    
-    - parameter sortDescriptor: a `NSSortDescriptor`
-    */
+     Initializes a `OrderBy` clause with a single sort descriptor
+     
+     - parameter sortDescriptor: a `NSSortDescriptor`
+     */
     public init(_ sortDescriptor: NSSortDescriptor) {
         
         self.init([sortDescriptor])
     }
     
     /**
-    Initializes a `OrderBy` clause with a series of `SortKey`s
-    
-    - parameter sortKey: a series of `SortKey`s
-    */
+     Initializes a `OrderBy` clause with a series of `SortKey`s
+     
+     - parameter sortKey: a series of `SortKey`s
+     */
     public init(_ sortKey: [SortKey]) {
         
         self.init(
@@ -121,11 +120,11 @@ public struct OrderBy: FetchClause, QueryClause, DeleteClause {
     }
     
     /**
-    Initializes a `OrderBy` clause with a series of `SortKey`s
-    
-    - parameter sortKey: a single `SortKey`
-    - parameter sortKeys: a series of `SortKey`s
-    */
+     Initializes a `OrderBy` clause with a series of `SortKey`s
+     
+     - parameter sortKey: a single `SortKey`
+     - parameter sortKeys: a series of `SortKey`s
+     */
     public init(_ sortKey: SortKey, _ sortKeys: SortKey...) {
         
         self.init([sortKey] + sortKeys)
@@ -138,7 +137,7 @@ public struct OrderBy: FetchClause, QueryClause, DeleteClause {
     
     public func applyToFetchRequest(fetchRequest: NSFetchRequest) {
         
-        if fetchRequest.sortDescriptors != nil {
+        if let sortDescriptors = fetchRequest.sortDescriptors where sortDescriptors != self.sortDescriptors {
             
             CoreStore.log(
                 .Warning,

CoreStore/Fetching and Querying/Concrete Clauses/Select.swift

@@ -2,7 +2,7 @@
 //  Select.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -30,16 +30,16 @@ import CoreData
 // MARK: - SelectResultType
 
 /**
-The `SelectResultType` protocol is implemented by return types supported by the `Select` clause.
-*/
+ The `SelectResultType` protocol is implemented by return types supported by the `Select` clause.
+ */
 public protocol SelectResultType { }
 
 
 // MARK: - SelectValueResultType
 
 /**
-The `SelectValueResultType` protocol is implemented by return types supported by the `queryValue(...)` methods.
-*/
+ The `SelectValueResultType` protocol is implemented by return types supported by the `queryValue(...)` methods.
+ */
 public protocol SelectValueResultType: SelectResultType {
     
     static func fromResultObject(result: AnyObject) -> Self?
@@ -49,8 +49,8 @@ public protocol SelectValueResultType: SelectResultType {
 // MARK: - SelectAttributesResultType
 
 /**
-The `SelectValueResultType` protocol is implemented by return types supported by the `queryAttributes(...)` methods.
-*/
+ The `SelectValueResultType` protocol is implemented by return types supported by the `queryAttributes(...)` methods.
+ */
 public protocol SelectAttributesResultType: SelectResultType {
     
     static func fromResultObjects(result: [AnyObject]) -> [[NSString: AnyObject]]
@@ -60,49 +60,47 @@ public protocol SelectAttributesResultType: SelectResultType {
 // MARK: - SelectTerm
 
 /**
-The `SelectTerm` is passed to the `Select` clause to indicate the attributes/aggregate keys to be queried.
-*/
+ The `SelectTerm` is passed to the `Select` clause to indicate the attributes/aggregate keys to be queried.
+ */
 public enum SelectTerm: StringLiteralConvertible {
     
-    // MARK: Public
-    
     /**
-    Provides a `SelectTerm` to a `Select` clause for querying an entity attribute. A shorter way to do the same is to assign from the string keypath directly:
-    
-        let fullName = CoreStore.queryValue(
-            From(MyPersonEntity),
-            Select<String>(.Attribute("fullName")),
-            Where("employeeID", isEqualTo: 1111)
-        )
-    
-    is equivalent to:
-    
-        let fullName = CoreStore.queryValue(
-            From(MyPersonEntity),
-            Select<String>("fullName"),
-            Where("employeeID", isEqualTo: 1111)
-        )
-    
-    - parameter keyPath: the attribute name
-    - returns: a `SelectTerm` to a `Select` clause for querying an entity attribute
-    */
+     Provides a `SelectTerm` to a `Select` clause for querying an entity attribute. A shorter way to do the same is to assign from the string keypath directly:
+     ```
+     let fullName = CoreStore.queryValue(
+         From(MyPersonEntity),
+         Select<String>(.Attribute("fullName")),
+         Where("employeeID", isEqualTo: 1111)
+     )
+     ```
+     is equivalent to:
+     ```
+     let fullName = CoreStore.queryValue(
+         From(MyPersonEntity),
+         Select<String>("fullName"),
+         Where("employeeID", isEqualTo: 1111)
+     )
+     ```
+     - parameter keyPath: the attribute name
+     - returns: a `SelectTerm` to a `Select` clause for querying an entity attribute
+     */
     public static func Attribute(keyPath: KeyPath) -> SelectTerm {
         
         return ._Attribute(keyPath)
     }
     
     /**
-    Provides a `SelectTerm` to a `Select` clause for querying the average value of an attribute.
-
-        let averageAge = CoreStore.queryValue(
-            From(MyPersonEntity),
-            Select<Int>(.Average("age"))
-        )
-    
-    - parameter keyPath: the attribute name
-    - parameter alias: the dictionary key to use to access the result. Ignored when the query return value is not an `NSDictionary`. If `nil`, the default key "average(<attributeName>)" is used
-    - returns: a `SelectTerm` to a `Select` clause for querying the average value of an attribute
-    */
+     Provides a `SelectTerm` to a `Select` clause for querying the average value of an attribute.
+     ```
+     let averageAge = CoreStore.queryValue(
+         From(MyPersonEntity),
+         Select<Int>(.Average("age"))
+     )
+     ```
+     - parameter keyPath: the attribute name
+     - parameter alias: the dictionary key to use to access the result. Ignored when the query return value is not an `NSDictionary`. If `nil`, the default key "average(<attributeName>)" is used
+     - returns: a `SelectTerm` to a `Select` clause for querying the average value of an attribute
+     */
     public static func Average(keyPath: KeyPath, As alias: KeyPath? = nil) -> SelectTerm {
         
         return ._Aggregate(
@@ -114,17 +112,17 @@ public enum SelectTerm: StringLiteralConvertible {
     }
     
     /**
-    Provides a `SelectTerm` to a `Select` clause for a count query.
-    
-        let numberOfEmployees = CoreStore.queryValue(
-            From(MyPersonEntity),
-            Select<Int>(.Count("employeeID"))
-        )
-    
-    - parameter keyPath: the attribute name
-    - parameter alias: the dictionary key to use to access the result. Ignored when the query return value is not an `NSDictionary`. If `nil`, the default key "count(<attributeName>)" is used
-    - returns: a `SelectTerm` to a `Select` clause for a count query
-    */
+     Provides a `SelectTerm` to a `Select` clause for a count query.
+     ```
+     let numberOfEmployees = CoreStore.queryValue(
+         From(MyPersonEntity),
+         Select<Int>(.Count("employeeID"))
+     )
+     ```
+     - parameter keyPath: the attribute name
+     - parameter alias: the dictionary key to use to access the result. Ignored when the query return value is not an `NSDictionary`. If `nil`, the default key "count(<attributeName>)" is used
+     - returns: a `SelectTerm` to a `Select` clause for a count query
+     */
     public static func Count(keyPath: KeyPath, As alias: KeyPath? = nil) -> SelectTerm {
         
         return ._Aggregate(
@@ -136,17 +134,17 @@ public enum SelectTerm: StringLiteralConvertible {
     }
     
     /**
-    Provides a `SelectTerm` to a `Select` clause for querying the maximum value for an attribute.
-    
-        let maximumAge = CoreStore.queryValue(
-            From(MyPersonEntity),
-            Select<Int>(.Maximum("age"))
-        )
-    
-    - parameter keyPath: the attribute name
-    - parameter alias: the dictionary key to use to access the result. Ignored when the query return value is not an `NSDictionary`. If `nil`, the default key "max(<attributeName>)" is used
-    - returns: a `SelectTerm` to a `Select` clause for querying the maximum value for an attribute
-    */
+     Provides a `SelectTerm` to a `Select` clause for querying the maximum value for an attribute.
+     ```
+     let maximumAge = CoreStore.queryValue(
+         From(MyPersonEntity),
+         Select<Int>(.Maximum("age"))
+     )
+     ```
+     - parameter keyPath: the attribute name
+     - parameter alias: the dictionary key to use to access the result. Ignored when the query return value is not an `NSDictionary`. If `nil`, the default key "max(<attributeName>)" is used
+     - returns: a `SelectTerm` to a `Select` clause for querying the maximum value for an attribute
+     */
     public static func Maximum(keyPath: KeyPath, As alias: KeyPath? = nil) -> SelectTerm {
         
         return ._Aggregate(
@@ -158,17 +156,17 @@ public enum SelectTerm: StringLiteralConvertible {
     }
     
     /**
-    Provides a `SelectTerm` to a `Select` clause for querying the minimum value for an attribute.
-    
-        let minimumAge = CoreStore.queryValue(
-            From(MyPersonEntity),
-            Select<Int>(.Minimum("age"))
-        )
-    
-    - parameter keyPath: the attribute name
-    - parameter alias: the dictionary key to use to access the result. Ignored when the query return value is not an `NSDictionary`. If `nil`, the default key "min(<attributeName>)" is used
-    - returns: a `SelectTerm` to a `Select` clause for querying the minimum value for an attribute
-    */
+     Provides a `SelectTerm` to a `Select` clause for querying the minimum value for an attribute.
+     ```
+     let minimumAge = CoreStore.queryValue(
+         From(MyPersonEntity),
+         Select<Int>(.Minimum("age"))
+     )
+     ```
+     - parameter keyPath: the attribute name
+     - parameter alias: the dictionary key to use to access the result. Ignored when the query return value is not an `NSDictionary`. If `nil`, the default key "min(<attributeName>)" is used
+     - returns: a `SelectTerm` to a `Select` clause for querying the minimum value for an attribute
+     */
     public static func Minimum(keyPath: KeyPath, As alias: KeyPath? = nil) -> SelectTerm {
         
         return ._Aggregate(
@@ -180,17 +178,17 @@ public enum SelectTerm: StringLiteralConvertible {
     }
     
     /**
-    Provides a `SelectTerm` to a `Select` clause for querying the sum value for an attribute.
-    
-        let totalAge = CoreStore.queryValue(
-            From(MyPersonEntity),
-            Select<Int>(.Sum("age"))
-        )
-    
-    - parameter keyPath: the attribute name
-    - parameter alias: the dictionary key to use to access the result. Ignored when the query return value is not an `NSDictionary`. If `nil`, the default key "sum(<attributeName>)" is used
-    - returns: a `SelectTerm` to a `Select` clause for querying the sum value for an attribute
-    */
+     Provides a `SelectTerm` to a `Select` clause for querying the sum value for an attribute.
+     ```
+     let totalAge = CoreStore.queryValue(
+         From(MyPersonEntity),
+         Select<Int>(.Sum("age"))
+     )
+     ```
+     - parameter keyPath: the attribute name
+     - parameter alias: the dictionary key to use to access the result. Ignored when the query return value is not an `NSDictionary`. If `nil`, the default key "sum(<attributeName>)" is used
+     - returns: a `SelectTerm` to a `Select` clause for querying the sum value for an attribute
+     */
     public static func Sum(keyPath: KeyPath, As alias: KeyPath? = nil) -> SelectTerm {
         
         return ._Aggregate(
@@ -230,68 +228,66 @@ public enum SelectTerm: StringLiteralConvertible {
 // MARK: - Select
 
 /**
-The `Select` clause indicates the attribute / aggregate value to be queried. The generic type is a `SelectResultType`, and will be used as the return type for the query. 
-
-You can bind the return type by specializing the initializer:
-
-    let maximumAge = CoreStore.queryValue(
-        From(MyPersonEntity),
-        Select<Int>(.Maximum("age"))
-    )
-
-or by casting the type of the return value:
-
-    let maximumAge: Int = CoreStore.queryValue(
-        From(MyPersonEntity),
-        Select(.Maximum("age"))
-    )
-
-Valid return types depend on the query:
-
-- for `queryValue(...)` methods:
-    - `Bool`
-    - `Int8`
-    - `Int16`
-    - `Int32`
-    - `Int64`
-    - `Double`
-    - `Float`
-    - `String`
-    - `NSNumber`
-    - `NSString`
-    - `NSDecimalNumber`
-    - `NSDate`
-    - `NSData`
-    - `NSManagedObjectID`
-    - `NSString`
-- for `queryAttributes(...)` methods:
-    - `NSDictionary`
-
-- parameter sortDescriptors: a series of `NSSortDescriptor`s
-*/
+ The `Select` clause indicates the attribute / aggregate value to be queried. The generic type is a `SelectResultType`, and will be used as the return type for the query.
+ 
+ You can bind the return type by specializing the initializer:
+ ```
+ let maximumAge = CoreStore.queryValue(
+     From(MyPersonEntity),
+     Select<Int>(.Maximum("age"))
+ )
+ ```
+ or by casting the type of the return value:
+ ```
+ let maximumAge: Int = CoreStore.queryValue(
+     From(MyPersonEntity),
+     Select(.Maximum("age"))
+ )
+ ```
+ Valid return types depend on the query:
+ 
+ - for `queryValue(...)` methods:
+     - `Bool`
+     - `Int8`
+     - `Int16`
+     - `Int32`
+     - `Int64`
+     - `Double`
+     - `Float`
+     - `String`
+     - `NSNumber`
+     - `NSString`
+     - `NSDecimalNumber`
+     - `NSDate`
+     - `NSData`
+     - `NSManagedObjectID`
+     - `NSString`
+ - for `queryAttributes(...)` methods:
+     - `NSDictionary`
+ 
+ - parameter sortDescriptors: a series of `NSSortDescriptor`s
+ */
 public struct Select<T: SelectResultType> {
     
-    // MARK: Public
-    
     /**
-    The `SelectResultType` type for the query's return value
-    */
+     The `SelectResultType` type for the query's return value
+     */
     public typealias ReturnType = T
     
     /**
-    Initializes a `Select` clause with a list of `SelectTerm`s
-    
-    - parameter selectTerm: a `SelectTerm`
-    - parameter selectTerms: a series of `SelectTerm`s
-    */
+     Initializes a `Select` clause with a list of `SelectTerm`s
+     
+     - parameter selectTerm: a `SelectTerm`
+     - parameter selectTerms: a series of `SelectTerm`s
+     */
     public init(_ selectTerm: SelectTerm, _ selectTerms: SelectTerm...) {
         
         self.selectTerms = [selectTerm] + selectTerms
     }
-
-
+    
+    
     // MARK: Internal
-
+    
     internal func applyToFetchRequest(fetchRequest: NSFetchRequest) {
         
         if fetchRequest.propertiesToFetch != nil {
@@ -406,11 +402,11 @@ extension Int8: SelectValueResultType {
     
     public static func fromResultObject(result: AnyObject) -> Int8? {
         
-        if let value = (result as? NSNumber)?.longLongValue {
+        guard let value = (result as? NSNumber)?.longLongValue else {
             
-            return numericCast(value) as Int8
+            return nil
         }
-        return nil
+        return numericCast(value) as Int8
     }
 }
 
@@ -426,11 +422,11 @@ extension Int16: SelectValueResultType {
     
     public static func fromResultObject(result: AnyObject) -> Int16? {
         
-        if let value = (result as? NSNumber)?.longLongValue {
+        guard let value = (result as? NSNumber)?.longLongValue else {
             
-            return numericCast(value) as Int16
+            return nil
         }
-        return nil
+        return numericCast(value) as Int16
     }
 }
 
@@ -446,11 +442,11 @@ extension Int32: SelectValueResultType {
     
     public static func fromResultObject(result: AnyObject) -> Int32? {
         
-        if let value = (result as? NSNumber)?.longLongValue {
+        guard let value = (result as? NSNumber)?.longLongValue else {
             
-            return numericCast(value) as Int32
+            return nil
         }
-        return nil
+        return numericCast(value) as Int32
     }
 }
 
@@ -482,11 +478,11 @@ extension Int: SelectValueResultType {
     
     public static func fromResultObject(result: AnyObject) -> Int? {
         
-        if let value = (result as? NSNumber)?.longLongValue {
+        guard let value = (result as? NSNumber)?.longLongValue else {
             
-            return numericCast(value) as Int
+            return nil
         }
-        return nil
+        return numericCast(value) as Int
     }
 }
 

CoreStore/Fetching and Querying/Concrete Clauses/Tweak.swift

@@ -2,7 +2,7 @@
 //  Tweak.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -30,27 +30,25 @@ import CoreData
 // MARK: - Tweak
 
 /**
-The `Tweak` clause allows fine-tuning the `NSFetchRequest` for a fetch or query.
-
-Sample usage:
-
-    let employees = transaction.fetchAll(
-        From(MyPersonEntity),
-        Tweak { (fetchRequest) -> Void in
-            fetchRequest.includesPendingChanges = false
-            fetchRequest.fetchLimit = 5
-        }
-    )
-*/
+ The `Tweak` clause allows fine-tuning the `NSFetchRequest` for a fetch or query.
+ Sample usage:
+ ```
+ let employees = transaction.fetchAll(
+     From(MyPersonEntity),
+     Tweak { (fetchRequest) -> Void in
+         fetchRequest.includesPendingChanges = false
+         fetchRequest.fetchLimit = 5
+     }
+ )
+ ```
+ */
 public struct Tweak: FetchClause, QueryClause, DeleteClause {
     
-    // MARK: Public
-    
     /**
-    Initializes a `Tweak` clause with a closure where the `NSFetchRequest` may be configured.
-    
-    - parameter customization: a list of key path strings to group results with
-    */
+     Initializes a `Tweak` clause with a closure where the `NSFetchRequest` may be configured.
+     
+     - parameter customization: a list of key path strings to group results with
+     */
     public init(_ customization: (fetchRequest: NSFetchRequest) -> Void) {
         
         self.customization = customization
@@ -65,5 +63,7 @@ public struct Tweak: FetchClause, QueryClause, DeleteClause {
     }
     
     
+    // MARK: Private
+    
     private let customization: (fetchRequest: NSFetchRequest) -> Void
 }

CoreStore/Fetching and Querying/Concrete Clauses/Where.swift

@@ -2,7 +2,7 @@
 //  Where.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -24,6 +24,7 @@
 //
 
 import Foundation
+import CoreData
 
 
 public func &&(left: Where, right: Where) -> Where {
@@ -45,73 +46,93 @@ public prefix func !(clause: Where) -> Where {
 // MARK: - Where
 
 /**
-The `Where` clause specifies the conditions for a fetch or a query.
-*/
+ The `Where` clause specifies the conditions for a fetch or a query.
+ */
 public struct Where: FetchClause, QueryClause, DeleteClause {
     
-    // MARK: Public
-    
     /**
-    Initializes a `Where` clause with an `NSPredicate`
-    
-    - parameter predicate: the `NSPredicate` for the fetch or query
-    */
+     Initializes a `Where` clause with an `NSPredicate`
+     
+     - parameter predicate: the `NSPredicate` for the fetch or query
+     */
     public init(_ predicate: NSPredicate) {
         
         self.predicate = predicate
     }
     
     /**
-    Initializes a `Where` clause with a predicate that always evaluates to `true`
-    */
+     Initializes a `Where` clause with a predicate that always evaluates to `true`
+     */
     public init() {
         
         self.init(true)
     }
     
     /**
-    Initializes a `Where` clause with a predicate that always evaluates to the specified boolean value
-    
-    - parameter value: the boolean value for the predicate
-    */
+     Initializes a `Where` clause with a predicate that always evaluates to the specified boolean value
+     
+     - parameter value: the boolean value for the predicate
+     */
     public init(_ value: Bool) {
         
         self.init(NSPredicate(value: value))
     }
     
     /**
-    Initializes a `Where` clause with a predicate using the specified string format and arguments
-    
-    - parameter format: the format string for the predicate
-    - parameter args: the arguments for `format`
-    */
+     Initializes a `Where` clause with a predicate using the specified string format and arguments
+     
+     - parameter format: the format string for the predicate
+     - parameter args: the arguments for `format`
+     */
     public init(_ format: String, _ args: NSObject...) {
         
         self.init(NSPredicate(format: format, argumentArray: args))
     }
     
     /**
-    Initializes a `Where` clause with a predicate using the specified string format and arguments
-    
-    - parameter format: the format string for the predicate
-    - parameter argumentArray: the arguments for `format`
-    */
+     Initializes a `Where` clause with a predicate using the specified string format and arguments
+     
+     - parameter format: the format string for the predicate
+     - parameter argumentArray: the arguments for `format`
+     */
     public init(_ format: String, argumentArray: [NSObject]?) {
         
         self.init(NSPredicate(format: format, argumentArray: argumentArray))
     }
     
     /**
-    Initializes a `Where` clause with a predicate using the specified string format and arguments
-    
-    - parameter format: the format string for the predicate
-    - parameter argumentArray: the arguments for `format`
-    */
+     Initializes a `Where` clause that compares equality
+     
+     - parameter keyPath: the keyPath to compare with
+     - parameter value: the arguments for the `==` operator
+     */
     public init(_ keyPath: KeyPath, isEqualTo value: NSObject?) {
         
         self.init(value == nil
             ? NSPredicate(format: "\(keyPath) == nil")
-            : NSPredicate(format: "\(keyPath) == %@", value!))
+            : NSPredicate(format: "\(keyPath) == %@", argumentArray: [value!]))
+    }
+    
+    /**
+     Initializes a `Where` clause that compares membership
+     
+     - parameter keyPath: the keyPath to compare with
+     - parameter list: the array to check membership of
+     */
+    public init(_ keyPath: KeyPath, isMemberOf list: NSArray) {
+        
+        self.init(NSPredicate(format: "\(keyPath) IN %@", list))
+    }
+    
+    /**
+     Initializes a `Where` clause that compares membership
+     
+     - parameter keyPath: the keyPath to compare with
+     - parameter list: the sequence to check membership of
+     */
+    public init<S: SequenceType where S.Generator.Element: NSObject>(_ keyPath: KeyPath, isMemberOf list: S) {
+        
+        self.init(NSPredicate(format: "\(keyPath) IN %@", Array(list) as NSArray))
     }
     
     public let predicate: NSPredicate
@@ -121,7 +142,7 @@ public struct Where: FetchClause, QueryClause, DeleteClause {
     
     public func applyToFetchRequest(fetchRequest: NSFetchRequest) {
         
-        if fetchRequest.predicate != nil {
+        if let predicate = fetchRequest.predicate where predicate != self.predicate {
             
             CoreStore.log(
                 .Warning,

CoreStore/Fetching and Querying/CoreStore+Querying.swift

@@ -2,7 +2,7 @@
 //  CoreStore+Querying.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -24,188 +24,250 @@
 //
 
 import Foundation
+import CoreData
+
 
 // MARK: - CoreStore
 
 public extension CoreStore {
     
-    // MARK: Public
+    /**
+     Using the `defaultStack`, fetches the `NSManagedObject` instance in the `DataStack`'s context from a reference created from a transaction or from a different managed object context.
+     
+     - parameter object: a reference to the object created/fetched outside the `DataStack`
+     - returns: the `NSManagedObject` instance if the object exists in the `DataStack`, or `nil` if not found.
+     */
+    @warn_unused_result
+    public static func fetchExisting<T: NSManagedObject>(object: T) -> T? {
+        
+        return self.defaultStack.fetchExisting(object)
+    }
     
     /**
-    Using the `defaultStack`, fetches the first `NSManagedObject` instance that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     Using the `defaultStack`, fetches the `NSManagedObject` instance in the `DataStack`'s context from an `NSManagedObjectID`.
+     
+     - parameter objectID: the `NSManagedObjectID` for the object
+     - returns: the `NSManagedObject` instance if the object exists in the `DataStack`, or `nil` if not found.
+     */
+    @warn_unused_result
+    public static func fetchExisting<T: NSManagedObject>(objectID: NSManagedObjectID) -> T? {
+        
+        return self.defaultStack.fetchExisting(objectID)
+    }
     
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the first `NSManagedObject` instance that satisfies the specified `FetchClause`s
-    */
+    /**
+     Using the `defaultStack`, fetches the `NSManagedObject` instances in the `DataStack`'s context from references created from a transaction or from a different managed object context.
+     
+     - parameter objects: an array of `NSManagedObject`s created/fetched outside the `DataStack`
+     - returns: the `NSManagedObject` array for objects that exists in the `DataStack`
+     */
+    @warn_unused_result
+    public static func fetchExisting<T: NSManagedObject, S: SequenceType where S.Generator.Element == T>(objects: S) -> [T] {
+        
+        return self.defaultStack.fetchExisting(objects)
+    }
+    
+    /**
+     Using the `defaultStack`, fetches the `NSManagedObject` instances in the `DataStack`'s context from a list of `NSManagedObjectID`.
+     
+     - parameter objectIDs: the `NSManagedObjectID` array for the objects
+     - returns: the `NSManagedObject` array for objects that exists in the `DataStack`
+     */
+    @warn_unused_result
+    public static func fetchExisting<T: NSManagedObject, S: SequenceType where S.Generator.Element == NSManagedObjectID>(objectIDs: S) -> [T] {
+        
+        return self.defaultStack.fetchExisting(objectIDs)
+    }
+    
+    /**
+     Using the `defaultStack`, fetches the first `NSManagedObject` instance that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the first `NSManagedObject` instance that satisfies the specified `FetchClause`s
+     */
+    @warn_unused_result
     public static func fetchOne<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> T? {
         
         return self.defaultStack.fetchOne(from, fetchClauses)
     }
     
     /**
-    Using the `defaultStack`, fetches the first `NSManagedObject` instance that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the first `NSManagedObject` instance that satisfies the specified `FetchClause`s
-    */
+     Using the `defaultStack`, fetches the first `NSManagedObject` instance that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the first `NSManagedObject` instance that satisfies the specified `FetchClause`s
+     */
+    @warn_unused_result
     public static func fetchOne<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> T? {
         
         return self.defaultStack.fetchOne(from, fetchClauses)
     }
     
     /**
-    Using the `defaultStack`, fetches all `NSManagedObject` instances that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: all `NSManagedObject` instances that satisfy the specified `FetchClause`s
-    */
+     Using the `defaultStack`, fetches all `NSManagedObject` instances that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: all `NSManagedObject` instances that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public static func fetchAll<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> [T]? {
         
         return self.defaultStack.fetchAll(from, fetchClauses)
     }
     
     /**
-    Using the `defaultStack`, fetches all `NSManagedObject` instances that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: all `NSManagedObject` instances that satisfy the specified `FetchClause`s
-    */
+     Using the `defaultStack`, fetches all `NSManagedObject` instances that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: all `NSManagedObject` instances that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public static func fetchAll<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> [T]? {
         
         return self.defaultStack.fetchAll(from, fetchClauses)
     }
     
     /**
-    Using the `defaultStack`, fetches the number of `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the number `NSManagedObject`s that satisfy the specified `FetchClause`s
-    */
+     Using the `defaultStack`, fetches the number of `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the number `NSManagedObject`s that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public static func fetchCount<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> Int? {
         
         return self.defaultStack.fetchCount(from, fetchClauses)
     }
     
     /**
-    Using the `defaultStack`, fetches the number of `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the number `NSManagedObject`s that satisfy the specified `FetchClause`s
-    */
+     Using the `defaultStack`, fetches the number of `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the number `NSManagedObject`s that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public static func fetchCount<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> Int? {
         
         return self.defaultStack.fetchCount(from, fetchClauses)
     }
     
     /**
-    Using the `defaultStack`, fetches the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s
-    */
+     Using the `defaultStack`, fetches the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s
+     */
+    @warn_unused_result
     public static func fetchObjectID<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> NSManagedObjectID? {
         
         return self.defaultStack.fetchObjectID(from, fetchClauses)
     }
     
     /**
-    Using the `defaultStack`, fetches the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s
-    */
+     Using the `defaultStack`, fetches the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s
+     */
+    @warn_unused_result
     public static func fetchObjectID<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> NSManagedObjectID? {
         
         return self.defaultStack.fetchObjectID(from, fetchClauses)
     }
     
     /**
-    Using the `defaultStack`, fetches the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s
-    */
+     Using the `defaultStack`, fetches the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public static func fetchObjectIDs<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> [NSManagedObjectID]? {
         
         return self.defaultStack.fetchObjectIDs(from, fetchClauses)
     }
     
     /**
-    Using the `defaultStack`, fetches the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s
-    */
+     Using the `defaultStack`, fetches the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public static func fetchObjectIDs<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> [NSManagedObjectID]? {
         
         return self.defaultStack.fetchObjectIDs(from, fetchClauses)
     }
     
     /**
-    Using the `defaultStack`, queries aggregate values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    
-    A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
-    - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
-    */
+     Using the `defaultStack`, queries aggregate values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     
+     A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
+     - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
+     */
+    @warn_unused_result
     public static func queryValue<T: NSManagedObject, U: SelectValueResultType>(from: From<T>, _ selectClause: Select<U>, _ queryClauses: QueryClause...) -> U? {
         
         return self.defaultStack.queryValue(from, selectClause, queryClauses)
     }
     
     /**
-    Using the `defaultStack`, queries aggregate values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    
-    A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
-    - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
-    */
+     Using the `defaultStack`, queries aggregate values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     
+     A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
+     - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
+     */
+    @warn_unused_result
     public static func queryValue<T: NSManagedObject, U: SelectValueResultType>(from: From<T>, _ selectClause: Select<U>, _ queryClauses: [QueryClause]) -> U? {
         
         return self.defaultStack.queryValue(from, selectClause, queryClauses)
     }
     
     /**
-    Using the `defaultStack`, queries a dictionary of attribtue values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    
-    A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
-    - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
-    */
+     Using the `defaultStack`, queries a dictionary of attribtue values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     
+     A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
+     - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
+     */
+    @warn_unused_result
     public static func queryAttributes<T: NSManagedObject>(from: From<T>, _ selectClause: Select<NSDictionary>, _ queryClauses: QueryClause...) -> [[NSString: AnyObject]]? {
         
         return self.defaultStack.queryAttributes(from, selectClause, queryClauses)
     }
     
     /**
-    Using the `defaultStack`, queries a dictionary of attribute values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    
-    A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
-    - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
-    */
+     Using the `defaultStack`, queries a dictionary of attribute values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     
+     A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
+     - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
+     */
+    @warn_unused_result
     public static func queryAttributes<T: NSManagedObject>(from: From<T>, _ selectClause: Select<NSDictionary>, _ queryClauses: [QueryClause]) -> [[NSString: AnyObject]]? {
         
         return self.defaultStack.queryAttributes(from, selectClause, queryClauses)

CoreStore/Fetching and Querying/DataStack+Querying.swift

@@ -2,7 +2,7 @@
 //  DataStack+Querying.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -25,22 +25,85 @@
 
 import Foundation
 import CoreData
-import GCDKit
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
 
 
 // MARK: - DataStack
 
 public extension DataStack {
     
-    // MARK: Public
+    /**
+     Fetches the `NSManagedObject` instance in the `DataStack`'s context from a reference created from a transaction or from a different managed object context.
+     
+     - parameter object: a reference to the object created/fetched outside the `DataStack`
+     - returns: the `NSManagedObject` instance if the object exists in the `DataStack`, or `nil` if not found.
+     */
+    @warn_unused_result
+    public func fetchExisting<T: NSManagedObject>(object: T) -> T? {
+        
+        do {
+            
+            return (try self.mainContext.existingObjectWithID(object.objectID) as! T)
+        }
+        catch _ {
+            
+            return nil
+        }
+    }
     
     /**
-    Fetches the first `NSManagedObject` instance that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     Fetches the `NSManagedObject` instance in the `DataStack`'s context from an `NSManagedObjectID`.
+     
+     - parameter objectID: the `NSManagedObjectID` for the object
+     - returns: the `NSManagedObject` instance if the object exists in the `DataStack`, or `nil` if not found.
+     */
+    @warn_unused_result
+    public func fetchExisting<T: NSManagedObject>(objectID: NSManagedObjectID) -> T? {
+        
+        do {
+            
+            return (try self.mainContext.existingObjectWithID(objectID) as! T)
+        }
+        catch _ {
+            
+            return nil
+        }
+    }
     
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the first `NSManagedObject` instance that satisfies the specified `FetchClause`s
-    */
+    /**
+     Fetches the `NSManagedObject` instances in the `DataStack`'s context from references created from a transaction or from a different managed object context.
+     
+     - parameter objects: an array of `NSManagedObject`s created/fetched outside the `DataStack`
+     - returns: the `NSManagedObject` array for objects that exists in the `DataStack`
+     */
+    @warn_unused_result
+    public func fetchExisting<T: NSManagedObject, S: SequenceType where S.Generator.Element == T>(objects: S) -> [T] {
+        
+        return objects.flatMap { (try? self.mainContext.existingObjectWithID($0.objectID)) as? T }
+    }
+    
+    /**
+     Fetches the `NSManagedObject` instances in the `DataStack`'s context from a list of `NSManagedObjectID`.
+     
+     - parameter objectIDs: the `NSManagedObjectID` array for the objects
+     - returns: the `NSManagedObject` array for objects that exists in the `DataStack`
+     */
+    @warn_unused_result
+    public func fetchExisting<T: NSManagedObject, S: SequenceType where S.Generator.Element == NSManagedObjectID>(objectIDs: S) -> [T] {
+        
+        return objectIDs.flatMap { (try? self.mainContext.existingObjectWithID($0)) as? T }
+    }
+    
+    /**
+     Fetches the first `NSManagedObject` instance that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the first `NSManagedObject` instance that satisfies the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchOne<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> T? {
         
         CoreStore.assert(
@@ -52,12 +115,13 @@ public extension DataStack {
     }
     
     /**
-    Fetches the first `NSManagedObject` instance that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the first `NSManagedObject` instance that satisfies the specified `FetchClause`s
-    */
+     Fetches the first `NSManagedObject` instance that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the first `NSManagedObject` instance that satisfies the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchOne<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> T? {
         
         CoreStore.assert(
@@ -69,12 +133,13 @@ public extension DataStack {
     }
     
     /**
-    Fetches all `NSManagedObject` instances that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: all `NSManagedObject` instances that satisfy the specified `FetchClause`s
-    */
+     Fetches all `NSManagedObject` instances that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: all `NSManagedObject` instances that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchAll<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> [T]? {
         
         CoreStore.assert(
@@ -86,12 +151,13 @@ public extension DataStack {
     }
     
     /**
-    Fetches all `NSManagedObject` instances that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: all `NSManagedObject` instances that satisfy the specified `FetchClause`s
-    */
+     Fetches all `NSManagedObject` instances that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: all `NSManagedObject` instances that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchAll<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> [T]? {
         
         CoreStore.assert(
@@ -103,12 +169,13 @@ public extension DataStack {
     }
     
     /**
-    Fetches the number of `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the number `NSManagedObject`s that satisfy the specified `FetchClause`s
-    */
+     Fetches the number of `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the number `NSManagedObject`s that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchCount<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> Int? {
         
         CoreStore.assert(
@@ -120,12 +187,13 @@ public extension DataStack {
     }
     
     /**
-    Fetches the number of `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the number `NSManagedObject`s that satisfy the specified `FetchClause`s
-    */
+     Fetches the number of `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the number `NSManagedObject`s that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchCount<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> Int? {
         
         CoreStore.assert(
@@ -137,12 +205,13 @@ public extension DataStack {
     }
     
     /**
-    Fetches the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s
-    */
+     Fetches the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchObjectID<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> NSManagedObjectID? {
         
         CoreStore.assert(
@@ -154,12 +223,13 @@ public extension DataStack {
     }
     
     /**
-    Fetches the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s
-    */
+     Fetches the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the `NSManagedObjectID` for the first `NSManagedObject` that satisfies the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchObjectID<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> NSManagedObjectID? {
         
         CoreStore.assert(
@@ -171,12 +241,13 @@ public extension DataStack {
     }
     
     /**
-    Fetches the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s
-    */
+     Fetches the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchObjectIDs<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> [NSManagedObjectID]? {
         
         CoreStore.assert(
@@ -188,12 +259,13 @@ public extension DataStack {
     }
     
     /**
-    Fetches the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s
-    */
+     Fetches the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for the fetch request. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: the `NSManagedObjectID` for all `NSManagedObject`s that satisfy the specified `FetchClause`s
+     */
+    @warn_unused_result
     public func fetchObjectIDs<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> [NSManagedObjectID]? {
         
         CoreStore.assert(
@@ -205,15 +277,16 @@ public extension DataStack {
     }
     
     /**
-    Queries aggregate values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    
-    A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
-    - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
-    */
+     Queries aggregate values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     
+     A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
+     - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
+     */
+    @warn_unused_result
     public func queryValue<T: NSManagedObject, U: SelectValueResultType>(from: From<T>, _ selectClause: Select<U>, _ queryClauses: QueryClause...) -> U? {
         
         CoreStore.assert(
@@ -225,15 +298,16 @@ public extension DataStack {
     }
     
     /**
-    Queries aggregate values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    
-    A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
-    - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
-    */
+     Queries aggregate values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     
+     A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
+     - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
+     */
+    @warn_unused_result
     public func queryValue<T: NSManagedObject, U: SelectValueResultType>(from: From<T>, _ selectClause: Select<U>, _ queryClauses: [QueryClause]) -> U? {
         
         CoreStore.assert(
@@ -245,15 +319,16 @@ public extension DataStack {
     }
     
     /**
-    Queries a dictionary of attribute values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    
-    A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
-    - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
-    */
+     Queries a dictionary of attribute values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     
+     A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
+     - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
+     */
+    @warn_unused_result
     public func queryAttributes<T: NSManagedObject>(from: From<T>, _ selectClause: Select<NSDictionary>, _ queryClauses: QueryClause...) -> [[NSString: AnyObject]]? {
         
         CoreStore.assert(
@@ -265,15 +340,16 @@ public extension DataStack {
     }
     
     /**
-    Queries a dictionary of attribute values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    
-    A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
-    - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
-    - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
-    */
+     Queries a dictionary of attribute values as specified by the `QueryClause`s. Requires at least a `Select` clause, and optional `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     
+     A "query" differs from a "fetch" in that it only retrieves values already stored in the persistent store. As such, values from unsaved transactions or contexts will not be incorporated in the query result.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter selectClause: a `Select<U>` clause indicating the properties to fetch, and with the generic type indicating the return type.
+     - parameter queryClauses: a series of `QueryClause` instances for the query request. Accepts `Where`, `OrderBy`, `GroupBy`, and `Tweak` clauses.
+     - returns: the result of the the query. The type of the return value is specified by the generic type of the `Select<U>` parameter.
+     */
+    @warn_unused_result
     public func queryAttributes<T: NSManagedObject>(from: From<T>, _ selectClause: Select<NSDictionary>, _ queryClauses: [QueryClause]) -> [[NSString: AnyObject]]? {
         
         CoreStore.assert(

CoreStore/Fetching and Querying/Protocol Clauses/ClauseTypes.swift

@@ -2,7 +2,7 @@
 //  ClauseTypes.swift
 //  CoreStore
 //
-//  Copyright (c) 2014 John Rommel Estropia
+//  Copyright © 2014 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -29,6 +29,9 @@ import CoreData
 
 // MARK: - FetchClause
 
+/**
+ The `FetchClause` implement clauses used to configure `NSFetchRequest`s.
+ */
 public protocol FetchClause {
     
     func applyToFetchRequest(fetchRequest: NSFetchRequest)
@@ -37,6 +40,9 @@ public protocol FetchClause {
 
 // MARK: - QueryClause
 
+/**
+ The `QueryClause` implement clauses used to configure `NSFetchRequest`s.
+ */
 public protocol QueryClause {
     
     func applyToFetchRequest(fetchRequest: NSFetchRequest)
@@ -45,6 +51,9 @@ public protocol QueryClause {
 
 // MARK: - DeleteClause
 
+/**
+ The `DeleteClause` implement clauses used to configure `NSFetchRequest`s.
+ */
 public protocol DeleteClause {
     
     func applyToFetchRequest(fetchRequest: NSFetchRequest)

CoreStore/Importing Data/BaseDataTransaction+Importing.swift

@@ -0,0 +1,248 @@
+//
+//  BaseDataTransaction+Importing.swift
+//  CoreStore
+//
+//  Copyright © 2015 John Rommel Estropia
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+//
+
+import Foundation
+import CoreData
+
+
+// MARK: - BaseDataTransaction
+
+public extension BaseDataTransaction {
+    
+    /**
+     Creates an `ImportableObject` by importing from the specified import source.
+     
+     - parameter into: an `Into` clause specifying the entity type
+     - parameter source: the object to import values from
+     - returns: the created `ImportableObject` instance, or `nil` if the import was ignored
+     */
+    public func importObject<T where T: NSManagedObject, T: ImportableObject>(
+        into: Into<T>,
+        source: T.ImportSource) throws -> T? {
+            
+            CoreStore.assert(
+                self.isRunningInAllowedQueue(),
+                "Attempted to import an object of type \(typeName(into.entityClass)) outside the transaction's designated queue."
+            )
+            
+            return try autoreleasepool {
+                
+                guard T.shouldInsertFromImportSource(source, inTransaction: self) else {
+                    
+                    return nil
+                }
+                
+                let object = self.create(into)
+                try object.didInsertFromImportSource(source, inTransaction: self)
+                return object
+            }
+    }
+    
+    /**
+     Updates an existing `ImportableObject` by importing values from the specified import source.
+     
+     - parameter object: the `NSManagedObject` to update
+     - parameter source: the object to import values from
+     */
+    public func importObject<T where T: NSManagedObject, T: ImportableObject>(
+        object: T,
+        source: T.ImportSource) throws {
+            
+            CoreStore.assert(
+                self.isRunningInAllowedQueue(),
+                "Attempted to import an object of type \(typeName(object)) outside the transaction's designated queue."
+            )
+            
+            try autoreleasepool {
+                
+                guard T.shouldInsertFromImportSource(source, inTransaction: self) else {
+                    
+                    return
+                }
+                
+                try object.didInsertFromImportSource(source, inTransaction: self)
+            }
+    }
+    
+    /**
+     Creates multiple `ImportableObject`s by importing from the specified array of import sources.
+     
+     - parameter into: an `Into` clause specifying the entity type
+     - parameter sourceArray: the array of objects to import values from
+     - returns: the array of created `ImportableObject` instances
+     */
+    public func importObjects<T, S: SequenceType where T: NSManagedObject, T: ImportableObject, S.Generator.Element == T.ImportSource>(
+        into: Into<T>,
+        sourceArray: S) throws -> [T] {
+            
+            CoreStore.assert(
+                self.isRunningInAllowedQueue(),
+                "Attempted to import an object of type \(typeName(into.entityClass)) outside the transaction's designated queue."
+            )
+            
+            return try autoreleasepool {
+                
+                return try sourceArray.flatMap { (source) -> T? in
+                    
+                    guard T.shouldInsertFromImportSource(source, inTransaction: self) else {
+                        
+                        return nil
+                    }
+                    
+                    return try autoreleasepool {
+                        
+                        let object = self.create(into)
+                        try object.didInsertFromImportSource(source, inTransaction: self)
+                        return object
+                    }
+                }
+            }
+    }
+    
+    /**
+     Updates an existing `ImportableUniqueObject` or creates a new instance by importing from the specified import source.
+     
+     - parameter into: an `Into` clause specifying the entity type
+     - parameter source: the object to import values from
+     - returns: the created/updated `ImportableUniqueObject` instance, or `nil` if the import was ignored
+     */
+    public func importUniqueObject<T where T: NSManagedObject, T: ImportableUniqueObject>(
+        into: Into<T>,
+        source: T.ImportSource) throws -> T?  {
+            
+            CoreStore.assert(
+                self.isRunningInAllowedQueue(),
+                "Attempted to import an object of type \(typeName(into.entityClass)) outside the transaction's designated queue."
+            )
+            
+            return try autoreleasepool {
+                
+                let uniqueIDKeyPath = T.uniqueIDKeyPath
+                guard let uniqueIDValue = try T.uniqueIDFromImportSource(source, inTransaction: self) else {
+                    
+                    return nil
+                }
+                
+                if let object = self.fetchOne(From(T), Where(uniqueIDKeyPath, isEqualTo: uniqueIDValue)) {
+                    
+                    guard T.shouldUpdateFromImportSource(source, inTransaction: self) else {
+                        
+                        return nil
+                    }
+                    
+                    try object.updateFromImportSource(source, inTransaction: self)
+                    return object
+                }
+                else {
+                    
+                    guard T.shouldInsertFromImportSource(source, inTransaction: self) else {
+                        
+                        return nil
+                    }
+                    
+                    let object = self.create(into)
+                    object.uniqueIDValue = uniqueIDValue
+                    try object.didInsertFromImportSource(source, inTransaction: self)
+                    return object
+                }
+            }
+    }
+    
+    /**
+     Updates existing `ImportableUniqueObject`s or creates them by importing from the specified array of import sources.
+     
+     - parameter into: an `Into` clause specifying the entity type
+     - parameter sourceArray: the array of objects to import values from
+     - parameter preProcess: a closure that lets the caller tweak the internal `UniqueIDType`-to-`ImportSource` mapping to be used for importing. Callers can remove from/add to/update `mapping` and return the updated array from the closure.
+     - returns: the array of created/updated `ImportableUniqueObject` instances
+     */
+    public func importUniqueObjects<T, S: SequenceType where T: NSManagedObject, T: ImportableUniqueObject, S.Generator.Element == T.ImportSource>(
+        into: Into<T>,
+        sourceArray: S,
+        @noescape preProcess: (mapping: [T.UniqueIDType: T.ImportSource]) throws -> [T.UniqueIDType: T.ImportSource] = { $0 }) throws -> [T] {
+            
+            CoreStore.assert(
+                self.isRunningInAllowedQueue(),
+                "Attempted to import an object of type \(typeName(into.entityClass)) outside the transaction's designated queue."
+            )
+            
+            return try autoreleasepool {
+                
+                var mapping = Dictionary<T.UniqueIDType, T.ImportSource>()
+                let sortedIDs = try autoreleasepool {
+                    
+                    return try sourceArray.flatMap { (source) -> T.UniqueIDType? in
+                        
+                        guard let uniqueIDValue = try T.uniqueIDFromImportSource(source, inTransaction: self) else {
+                            
+                            return nil
+                        }
+                        
+                        mapping[uniqueIDValue] = source
+                        return uniqueIDValue
+                    }
+                }
+                
+                mapping = try autoreleasepool { try preProcess(mapping: mapping) }
+                
+                var objects = Dictionary<T.UniqueIDType, T>()
+                for object in self.fetchAll(From(T), Where(T.uniqueIDKeyPath, isMemberOf: mapping.keys)) ?? [] {
+                    
+                    try autoreleasepool {
+                        
+                        let uniqueIDValue = object.uniqueIDValue
+                        
+                        guard let source = mapping.removeValueForKey(uniqueIDValue)
+                            where T.shouldUpdateFromImportSource(source, inTransaction: self) else {
+                                
+                                return
+                        }
+                        
+                        try object.updateFromImportSource(source, inTransaction: self)
+                        objects[uniqueIDValue] = object
+                    }
+                }
+                
+                for (uniqueIDValue, source) in mapping {
+                    
+                    try autoreleasepool {
+                        
+                        guard T.shouldInsertFromImportSource(source, inTransaction: self) else {
+                            
+                            return
+                        }
+                        
+                        let object = self.create(into)
+                        object.uniqueIDValue = uniqueIDValue
+                        try object.didInsertFromImportSource(source, inTransaction: self)
+                        
+                        objects[uniqueIDValue] = object
+                    }
+                }
+                
+                return sortedIDs.flatMap { objects[$0] }
+            }
+    }
+}

CoreStore/Importing Data/ImportableObject.swift

@@ -0,0 +1,85 @@
+//
+//  ImportableObject.swift
+//  CoreStore
+//
+//  Copyright © 2015 John Rommel Estropia
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+//
+
+import Foundation
+import CoreData
+
+
+// MARK: - ImportableObject
+
+/**
+ `NSManagedObject` subclasses that conform to the `ImportableObject` protocol can be imported from a specified `ImportSource`. This allows transactions to create and insert instances this way:
+ ```
+ class MyPersonEntity: NSManagedObject, ImportableObject {
+     typealias ImportSource = NSDictionary
+     // ...
+ }
+ 
+ CoreStore.beginAsynchronous { (transaction) -> Void in
+     let json: NSDictionary = // ...
+     let person = try! transaction.importObject(
+         Into(MyPersonEntity),
+         source: json
+     )
+     // ...
+     transaction.commit()
+ }
+ ```
+ */
+public protocol ImportableObject: class {
+    
+    /**
+     The data type for the import source. This is most commonly an `NSDictionary` or another external source such as an `NSUserDefaults`.
+     */
+    associatedtype ImportSource
+    
+    /**
+     Return `true` if an object should be created from `source`. Return `false` to ignore and skip `source`. The default implementation returns `true`.
+     
+     - parameter source: the object to import from
+     - parameter transaction: the transaction that invoked the import. Use the transaction to fetch or create related objects if needed.
+     - returns: `true` if an object should be created from `source`. Return `false` to ignore.
+     */
+    static func shouldInsertFromImportSource(source: ImportSource, inTransaction transaction: BaseDataTransaction) -> Bool
+    
+    /**
+     Implements the actual importing of data from `source`. Implementers should pull values from `source` and assign them to the receiver's attributes. Note that throwing from this method will cause subsequent imports that are part of the same `importObjects(:sourceArray:)` call to be cancelled.
+     
+     - parameter source: the object to import from
+     - parameter transaction: the transaction that invoked the import. Use the transaction to fetch or create related objects if needed.
+    */
+    func didInsertFromImportSource(source: ImportSource, inTransaction transaction: BaseDataTransaction) throws
+}
+
+
+// MARK: - ImportableObject (Default Implementations)
+
+public extension ImportableObject {
+    
+    static func shouldInsertFromImportSource(source: ImportSource, inTransaction transaction: BaseDataTransaction) -> Bool {
+        
+        return true
+    }
+}

CoreStore/Importing Data/ImportableUniqueObject.swift

@@ -0,0 +1,137 @@
+//
+//  ImportableUniqueObject.swift
+//  CoreStore
+//
+//  Copyright © 2015 John Rommel Estropia
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+//
+
+import Foundation
+import CoreData
+
+
+// MARK: - ImportableUniqueObject
+
+/**
+ `NSManagedObject` subclasses that conform to the `ImportableUniqueObject` protocol can be imported from a specified `ImportSource`. This allows transactions to either update existing objects or create new instances this way:
+ ```
+ class MyPersonEntity: NSManagedObject, ImportableUniqueObject {
+     typealias ImportSource = NSDictionary
+     typealias UniqueIDType = NSString
+     // ...
+ }
+ 
+ CoreStore.beginAsynchronous { (transaction) -> Void in
+     let json: NSDictionary = // ...
+     let person = try! transaction.importUniqueObject(
+         Into(MyPersonEntity),
+         source: json
+     )
+     // ...
+     transaction.commit()
+ }
+ ```
+ */
+public protocol ImportableUniqueObject: ImportableObject {
+    
+    /**
+     The data type for the import source. This is most commonly an `NSDictionary` or another external source such as an `NSUserDefaults`.
+     */
+    associatedtype ImportSource
+    
+    /**
+     The data type for the entity's unique ID attribute
+     */
+    associatedtype UniqueIDType: NSObject
+    
+    /**
+     The keyPath to the entity's unique ID attribute
+     */
+    static var uniqueIDKeyPath: String { get }
+    
+    /**
+     The object's unique ID value
+     */
+    var uniqueIDValue: UniqueIDType { get set }
+    
+    /**
+     Return `true` if an object should be created from `source`. Return `false` to ignore and skip `source`. The default implementation returns the value returned by the `shouldUpdateFromImportSource(:inTransaction:)` implementation.
+     
+     - parameter source: the object to import from
+     - parameter transaction: the transaction that invoked the import. Use the transaction to fetch or create related objects if needed.
+     - returns: `true` if an object should be created from `source`. Return `false` to ignore.
+     */
+    static func shouldInsertFromImportSource(source: ImportSource, inTransaction transaction: BaseDataTransaction) -> Bool
+    
+    /**
+     Return `true` if an object should be updated from `source`. Return `false` to ignore and skip `source`. The default implementation returns `true`.
+     
+     - parameter source: the object to import from
+     - parameter transaction: the transaction that invoked the import. Use the transaction to fetch or create related objects if needed.
+     - returns: `true` if an object should be updated from `source`. Return `false` to ignore.
+     */
+    static func shouldUpdateFromImportSource(source: ImportSource, inTransaction transaction: BaseDataTransaction) -> Bool
+    
+    /**
+     Return the unique ID as extracted from `source`. This method is called before `shouldInsertFromImportSource(...)` or `shouldUpdateFromImportSource(...)`. Return `nil` to skip importing from `source`. Note that throwing from this method will cause subsequent imports that are part of the same `importUniqueObjects(:sourceArray:)` call to be cancelled.
+     
+     - parameter source: the object to import from
+     - parameter transaction: the transaction that invoked the import. Use the transaction to fetch or create related objects if needed.
+     - returns: the unique ID as extracted from `source`, or `nil` to skip importing from `source`.
+     */
+    static func uniqueIDFromImportSource(source: ImportSource, inTransaction transaction: BaseDataTransaction) throws -> UniqueIDType?
+    
+    /**
+     Implements the actual importing of data from `source`. This method is called just after the object is created and assigned its unique ID as returned from `uniqueIDFromImportSource(...)`. Implementers should pull values from `source` and assign them to the receiver's attributes. Note that throwing from this method will cause subsequent imports that are part of the same `importUniqueObjects(:sourceArray:)` call to be cancelled. The default implementation simply calls `updateFromImportSource(...)`.
+     
+     - parameter source: the object to import from
+     - parameter transaction: the transaction that invoked the import. Use the transaction to fetch or create related objects if needed.
+     */
+    func didInsertFromImportSource(source: ImportSource, inTransaction transaction: BaseDataTransaction) throws
+    
+    /**
+     Implements the actual importing of data from `source`. This method is called just after the existing object is fetched using its unique ID. Implementers should pull values from `source` and assign them to the receiver's attributes. Note that throwing from this method will cause subsequent imports that are part of the same `importUniqueObjects(:sourceArray:)` call to be cancelled.
+     
+     - parameter source: the object to import from
+     - parameter transaction: the transaction that invoked the import. Use the transaction to fetch or create related objects if needed.
+     */
+    func updateFromImportSource(source: ImportSource, inTransaction transaction: BaseDataTransaction) throws
+}
+
+
+// MARK: - ImportableUniqueObject (Default Implementations)
+
+public extension ImportableUniqueObject {
+    
+    static func shouldInsertFromImportSource(source: ImportSource, inTransaction transaction: BaseDataTransaction) -> Bool {
+        
+        return self.shouldUpdateFromImportSource(source, inTransaction: transaction)
+    }
+    
+    static func shouldUpdateFromImportSource(source: ImportSource, inTransaction transaction: BaseDataTransaction) -> Bool {
+        
+        return true
+    }
+    
+    func didInsertFromImportSource(source: ImportSource, inTransaction transaction: BaseDataTransaction) throws {
+        
+        try self.updateFromImportSource(source, inTransaction: transaction)
+    }
+}

CoreStore/Info.plist

@@ -15,7 +15,7 @@
 	<key>CFBundlePackageType</key>
 	<string>FMWK</string>
 	<key>CFBundleShortVersionString</key>
-	<string>1.0.1</string>
+	<string>1.6.8</string>
 	<key>CFBundleSignature</key>
 	<string>????</string>
 	<key>CFBundleVersion</key>

CoreStore/Internal/AssociatedObjects.swift

@@ -2,7 +2,7 @@
 //  NSObject+CoreStore.swift
 //  CoreStore
 //
-//  Copyright (c) 2014 John Rommel Estropia
+//  Copyright © 2014 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal

CoreStore/Internal/CoreStoreFetchRequest.swift

@@ -0,0 +1,43 @@
+//
+//  CoreStoreFetchRequest.swift
+//  CoreStore
+//
+//  Copyright © 2016 John Rommel Estropia
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+//
+
+import Foundation
+import CoreData
+
+
+// MARK: - CoreStoreFetchRequest
+
+// Bugfix for NSFetchRequest messing up memory management for `affectedStores`
+// http://stackoverflow.com/questions/14396375/nsfetchedresultscontroller-crashes-in-ios-6-if-affectedstores-is-specified
+internal final class CoreStoreFetchRequest: NSFetchRequest {
+    
+    override var affectedStores: [NSPersistentStore]? {
+        
+        get { return self.safeAffectedStores }
+        set { self.safeAffectedStores = newValue }
+    }
+    
+    private var safeAffectedStores: [NSPersistentStore]?
+}

CoreStore/Internal/CoreStoreFetchedResultsController.swift

@@ -0,0 +1,110 @@
+//
+//  CoreStoreFetchedResultsController.swift
+//  CoreStore
+//
+//  Copyright © 2016 John Rommel Estropia
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+//
+
+import Foundation
+import CoreData
+
+
+// MARK: - CoreStoreFetchedResultsController
+
+@available(OSX, unavailable)
+internal final class CoreStoreFetchedResultsController<T: NSManagedObject>: NSFetchedResultsController {
+    
+    
+    // MARK: Internal
+    
+    internal convenience init<T>(dataStack: DataStack, fetchRequest: NSFetchRequest, from: From<T>? = nil, sectionBy: SectionBy? = nil, fetchClauses: [FetchClause]) {
+        
+        self.init(
+            context: dataStack.mainContext,
+            fetchRequest: fetchRequest,
+            from: from,
+            sectionBy: sectionBy,
+            fetchClauses: fetchClauses
+        )
+    }
+    
+    internal init<T>(context: NSManagedObjectContext, fetchRequest: NSFetchRequest, from: From<T>? = nil, sectionBy: SectionBy? = nil, fetchClauses: [FetchClause]) {
+        
+        CoreStore.assert(
+            fetchClauses.filter { $0 is OrderBy }.count > 0,
+            "An \(typeName(NSFetchedResultsController)) requires an OrderBy clause."
+        )
+        from?.applyToFetchRequest(fetchRequest, context: context, applyAffectedStores: false)
+        for clause in fetchClauses {
+            
+            clause.applyToFetchRequest(fetchRequest)
+        }
+        
+        if let from = from {
+            
+            self.reapplyAffectedStores = { fetchRequest, context in
+                
+                return from.applyAffectedStoresForFetchedRequest(fetchRequest, context: context)
+            }
+        }
+        else {
+            
+            guard let from = (fetchRequest.entity.flatMap { $0.managedObjectClassName }).flatMap(NSClassFromString).flatMap(From.init) else {
+                
+                fatalError("Attempted to create an \(typeName(NSFetchedResultsController)) without a  From clause or an NSEntityDescription.")
+            }
+            
+            self.reapplyAffectedStores = { fetchRequest, context in
+                
+                return from.applyAffectedStoresForFetchedRequest(fetchRequest, context: context)
+            }
+        }
+        
+        super.init(
+            fetchRequest: fetchRequest,
+            managedObjectContext: context,
+            sectionNameKeyPath: sectionBy?.sectionKeyPath,
+            cacheName: nil
+        )
+    }
+    
+    internal func performFetchFromSpecifiedStores() throws {
+        
+        if !self.reapplyAffectedStores(fetchRequest: self.fetchRequest, context: self.managedObjectContext) {
+            
+            CoreStore.log(
+                .Warning,
+                message: "Attempted to perform a fetch on an \(typeName(NSFetchedResultsController)) but could not find any persistent store for the entity \(typeName(self.fetchRequest.entityName))"
+            )
+        }
+        try self.performFetch()
+    }
+    
+    deinit {
+        
+        self.delegate = nil
+    }
+    
+    
+    // MARK: Private
+    
+    private let reapplyAffectedStores: (fetchRequest: NSFetchRequest, context: NSManagedObjectContext) -> Bool
+}

CoreStore/Internal/FetchedResultsControllerDelegate.swift

@@ -0,0 +1,219 @@
+//
+//  FetchedResultsControllerDelegate.swift
+//  CoreStore
+//
+//  Copyright © 2015 John Rommel Estropia
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+//
+
+import Foundation
+import CoreData
+
+
+// MARK: - FetchedResultsControllerHandler
+
+@available(OSX, unavailable)
+internal protocol FetchedResultsControllerHandler: class {
+    
+    func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?)
+    
+    func controller(controller: NSFetchedResultsController, didChangeSection sectionInfo: NSFetchedResultsSectionInfo, atIndex sectionIndex: Int, forChangeType type: NSFetchedResultsChangeType)
+    
+    func controllerWillChangeContent(controller: NSFetchedResultsController)
+    
+    func controllerDidChangeContent(controller: NSFetchedResultsController)
+    
+    func controller(controller: NSFetchedResultsController, sectionIndexTitleForSectionName sectionName: String?) -> String?
+}
+
+
+// MARK: - FetchedResultsControllerDelegate
+
+@available(OSX, unavailable)
+internal final class FetchedResultsControllerDelegate: NSObject, NSFetchedResultsControllerDelegate {
+    
+    // MARK: Internal
+    
+    internal var enabled = true
+    
+    internal weak var handler: FetchedResultsControllerHandler?
+    internal weak var fetchedResultsController: NSFetchedResultsController? {
+        
+        didSet {
+            
+            oldValue?.delegate = nil
+            self.fetchedResultsController?.delegate = self
+        }
+    }
+    
+    deinit {
+        
+        self.fetchedResultsController?.delegate = nil
+    }
+    
+    
+    // MARK: NSFetchedResultsControllerDelegate
+    
+    @objc dynamic func controllerWillChangeContent(controller: NSFetchedResultsController) {
+        
+        guard self.enabled else {
+            
+            return
+        }
+        
+        self.deletedSections = []
+        self.insertedSections = []
+        
+        self.handler?.controllerWillChangeContent(controller)
+    }
+    
+    @objc dynamic func controllerDidChangeContent(controller: NSFetchedResultsController) {
+        
+        guard self.enabled else {
+            
+            return
+        }
+        
+        self.handler?.controllerDidChangeContent(controller)
+    }
+    
+    @objc dynamic func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
+        
+        guard self.enabled else {
+            
+            return
+        }
+        
+        guard let actualType = NSFetchedResultsChangeType(rawValue: type.rawValue) else {
+            
+            // This fix is for a bug where iOS passes 0 for NSFetchedResultsChangeType, but this is not a valid enum case.
+            // Swift will then always execute the first case of the switch causing strange behaviour.
+            // https://forums.developer.apple.com/thread/12184#31850
+            return
+        }
+        
+        // This whole dance is a workaround for a nasty bug introduced in XCode 7 targeted at iOS 8 devices
+        // http://stackoverflow.com/questions/31383760/ios-9-attempt-to-delete-and-reload-the-same-index-path/31384014#31384014
+        // https://forums.developer.apple.com/message/9998#9998
+        // https://forums.developer.apple.com/message/31849#31849
+        
+        switch actualType {
+            
+        case .Update:
+            guard let section = indexPath?.indexAtPosition(0) else {
+                
+                return
+            }
+            if self.deletedSections.contains(section)
+                || self.insertedSections.contains(section) {
+                    
+                    return
+            }
+            
+        case .Move:
+            guard let indexPath = indexPath, let newIndexPath = newIndexPath else {
+                
+                return
+            }
+            guard indexPath == newIndexPath else {
+                
+                break
+            }
+            if self.insertedSections.contains(indexPath.indexAtPosition(0)) {
+                
+                // Observers that handle the .Move change are advised to delete then reinsert the object instead of just moving. This is especially true when indexPath and newIndexPath are equal. For example, calling tableView.moveRowAtIndexPath(_:toIndexPath) when both indexPaths are the same will crash the tableView.
+                self.handler?.controller(
+                    controller,
+                    didChangeObject: anObject,
+                    atIndexPath: indexPath,
+                    forChangeType: .Move,
+                    newIndexPath: newIndexPath
+                )
+                return
+            }
+            if self.deletedSections.contains(indexPath.indexAtPosition(0)) {
+                
+                self.handler?.controller(
+                    controller,
+                    didChangeObject: anObject,
+                    atIndexPath: nil,
+                    forChangeType: .Insert,
+                    newIndexPath: indexPath
+                )
+                return
+            }
+            self.handler?.controller(
+                controller,
+                didChangeObject: anObject,
+                atIndexPath: indexPath,
+                forChangeType: .Update,
+                newIndexPath: nil
+            )
+            return
+            
+        default:
+            break
+        }
+        
+        self.handler?.controller(
+            controller,
+            didChangeObject: anObject,
+            atIndexPath: indexPath,
+            forChangeType: actualType,
+            newIndexPath: newIndexPath
+        )
+    }
+    
+    @objc dynamic func controller(controller: NSFetchedResultsController, didChangeSection sectionInfo: NSFetchedResultsSectionInfo, atIndex sectionIndex: Int, forChangeType type: NSFetchedResultsChangeType) {
+        
+        guard self.enabled else {
+            
+            return
+        }
+        
+        switch type {
+            
+        case .Delete:   self.deletedSections.insert(sectionIndex)
+        case .Insert:   self.insertedSections.insert(sectionIndex)
+        default: break
+        }
+        
+        self.handler?.controller(
+            controller,
+            didChangeSection: sectionInfo,
+            atIndex: sectionIndex,
+            forChangeType: type
+        )
+    }
+    
+    @objc dynamic func controller(controller: NSFetchedResultsController, sectionIndexTitleForSectionName sectionName: String) -> String? {
+        
+        return self.handler?.controller(
+            controller,
+            sectionIndexTitleForSectionName: sectionName
+        )
+    }
+    
+    
+    // MARK: Private
+    
+    private var deletedSections = Set<Int>()
+    private var insertedSections = Set<Int>()
+}

CoreStore/Internal/Functions.swift

@@ -1,8 +1,8 @@
 //
-//  DetachedDataTransaction.swift
+//  Functions.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2014 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -24,38 +24,58 @@
 //
 
 import Foundation
-import GCDKit
 
-
-// MARK: - DetachedDataTransaction
-
-/**
-The `DetachedDataTransaction` provides an interface for non-contiguous `NSManagedObject` creates, updates, and deletes. This is useful for making temporary changes, such as partially filled forms. A detached transaction object should typically be only used from the main queue.
-*/
-public final class DetachedDataTransaction: BaseDataTransaction {
+internal func autoreleasepool<T>(@noescape closure: () -> T) -> T {
     
-    // MARK: Public
-    
-    /**
-    Saves the transaction changes asynchronously. For a `DetachedDataTransaction`, multiple commits are allowed, although it is the developer's responsibility to ensure a reasonable leeway to prevent blocking the main thread.
-    
-    - parameter completion: the block executed after the save completes. Success or failure is reported by the `SaveResult` argument of the block.
-    */
-    public func commit(completion: (result: SaveResult) -> Void) {
+    var closureValue: T!
+    ObjectiveC.autoreleasepool {
         
-        self.context.saveAsynchronouslyWithCompletion { (result) -> Void in
+        closureValue = closure()
+    }
+    
+    return closureValue
+}
+
+internal func autoreleasepool<T>(@noescape closure: () throws -> T) throws -> T {
+    
+    var closureValue: T!
+    var closureError: ErrorType?
+    ObjectiveC.autoreleasepool {
+        
+        do {
             
-            self.result = result
-            completion(result: result)
+            closureValue = try closure()
+        }
+        catch {
+            
+            closureError = error
         }
     }
     
-    
-    // MARK: Internal
-    
-    internal override var bypassesQueueing: Bool {
+    if let closureError = closureError {
         
-        return true
+        throw closureError
     }
+    return closureValue
 }
 
+internal func autoreleasepool(@noescape closure: () throws -> Void) throws {
+    
+    var closureError: ErrorType?
+    ObjectiveC.autoreleasepool {
+        
+        do {
+            
+            try closure()
+        }
+        catch {
+            
+            closureError = error
+        }
+    }
+    
+    if let closureError = closureError {
+        
+        throw closureError
+    }
+}

CoreStore/Internal/MigrationManager.swift

@@ -2,7 +2,7 @@
 //  MigrationManager.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -37,11 +37,12 @@ internal final class MigrationManager: NSMigrationManager, NSProgressReporting {
         
         super.didChangeValueForKey(key)
         
-        if key == "migrationProgress" {
+        guard key == "migrationProgress" else {
             
-            let progress = self.progress
-            progress.completedUnitCount = Int64(Float(progress.totalUnitCount) * self.migrationProgress)
+            return
         }
+        let progress = self.progress
+        progress.completedUnitCount = Int64(Float(progress.totalUnitCount) * self.migrationProgress)
     }
     
     

CoreStore/Internal/NSFileManager+Setup.swift

@@ -17,22 +17,10 @@ internal extension NSFileManager {
     
     internal func removeSQLiteStoreAtURL(fileURL: NSURL) {
         
-        do {
-            
-            try self.removeItemAtURL(fileURL)
-        }
-        catch _ { }
+        _ = try? self.removeItemAtURL(fileURL)
         
-        do {
-            
-            try self.removeItemAtPath(fileURL.path!.stringByAppendingString("-shm"))
-        }
-        catch _ { }
-        
-        do {
-            
-            try self.removeItemAtPath(fileURL.path!.stringByAppendingString("-wal"))
-        }
-        catch _ { }
+        let filePath = fileURL.path!
+        _ = try? self.removeItemAtPath(filePath.stringByAppendingString("-shm"))
+        _ = try? self.removeItemAtPath(filePath.stringByAppendingString("-wal"))
     }
 }

CoreStore/Internal/NSManagedObject+Transaction.swift

@@ -1,122 +0,0 @@
-//
-//  NSManagedObject+Transaction.swift
-//  CoreStore
-//
-//  Copyright (c) 2014 John Rommel Estropia
-//
-//  Permission is hereby granted, free of charge, to any person obtaining a copy
-//  of this software and associated documentation files (the "Software"), to deal
-//  in the Software without restriction, including without limitation the rights
-//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-//  copies of the Software, and to permit persons to whom the Software is
-//  furnished to do so, subject to the following conditions:
-//
-//  The above copyright notice and this permission notice shall be included in all
-//  copies or substantial portions of the Software.
-//
-//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-//  SOFTWARE.
-//
-
-import Foundation
-import CoreData
-
-
-// MARK: - NSManagedObject
-
-internal extension NSManagedObject {
-    
-    // MARK: Internal
-    
-    internal dynamic class func createInContext(context: NSManagedObjectContext) -> Self {
-        
-        return self.init(
-            entity: context.entityDescriptionForEntityType(self)!,
-            insertIntoManagedObjectContext: context
-        )
-    }
-    
-    internal dynamic class func inContext(context: NSManagedObjectContext, withObjectID objectID: NSManagedObjectID) -> Self? {
-        
-        return self.typedObjectInContext(context, objectID: objectID)
-    }
-    
-    internal func inContext(context: NSManagedObjectContext) -> Self? {
-        
-        return self.typedObjectInContext(context)
-    }
-    
-    internal func deleteFromContext() {
-        
-        self.managedObjectContext?.deleteObject(self)
-    }
-    
-    
-    // MARK: Private
-    
-    private class func typedObjectInContext<T: NSManagedObject>(context: NSManagedObjectContext, objectID: NSManagedObjectID) -> T? {
-        
-        do {
-            
-            let existingObject = try context.existingObjectWithID(objectID)
-            return (existingObject as! T)
-        }
-        catch {
-            
-            CoreStore.handleError(
-                error as NSError,
-                "Failed to load existing \(typeName(self)) in context."
-            )
-            return nil
-        }
-    }
-    
-    private func typedObjectInContext<T: NSManagedObject>(context: NSManagedObjectContext) -> T? {
-        
-        let objectID = self.objectID
-        if objectID.temporaryID {
-
-            var objectIDError: NSError?
-            let didSucceed = withExtendedLifetime(self.managedObjectContext) { (context: NSManagedObjectContext?) -> Bool in
-                
-                do {
-                    
-                    try context?.obtainPermanentIDsForObjects([self])
-                    return true
-                }
-                catch {
-                    
-                    objectIDError = error as NSError
-                    return false
-                }
-            }
-            if didSucceed != true {
-                
-                CoreStore.handleError(
-                    objectIDError ?? NSError(coreStoreErrorCode: .UnknownError),
-                    "Failed to obtain permanent ID for object."
-                )
-                return nil
-            }
-        }
-
-        do {
-            
-            let existingObject = try context.existingObjectWithID(objectID)
-            return (existingObject as! T)
-        }
-        catch {
-            
-            CoreStore.handleError(
-                error as NSError,
-                "Failed to load existing \(typeName(self)) in context."
-            )
-            return nil
-        }
-    }
-}

CoreStore/Internal/NSManagedObjectContext+CoreStore.swift

@@ -2,7 +2,7 @@
 //  NSManagedObjectContext+CoreStore.swift
 //  CoreStore
 //
-//  Copyright (c) 2014 John Rommel Estropia
+//  Copyright © 2014 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -25,7 +25,9 @@
 
 import Foundation
 import CoreData
-import GCDKit
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
 
 
 // MARK: - NSManagedObjectContext
@@ -61,19 +63,28 @@ internal extension NSManagedObjectContext {
     
     internal func entityDescriptionForEntityClass(entity: AnyClass) -> NSEntityDescription? {
         
-        if let entityName = self.parentStack?.entityNameForEntityClass(entity) {
-
-            return NSEntityDescription.entityForName(
-                entityName,
-                inManagedObjectContext: self
-            )
+        guard let entityName = self.parentStack?.entityNameForEntityClass(entity) else {
+            
+            return nil
         }
-        return nil
+        return NSEntityDescription.entityForName(
+            entityName,
+            inManagedObjectContext: self
+        )
     }
     
     internal func setupForCoreStoreWithContextName(contextName: String) {
-        
-        self.name = contextName
+
+        #if USE_FRAMEWORKS
+            
+            self.name = contextName
+        #else
+            
+            if #available(iOS 8.0, *) {
+                
+                self.name = contextName
+            }
+        #endif
         
         self.observerForWillSaveNotification = NotificationObserver(
             notificationName: NSManagedObjectContextWillSaveNotification,
@@ -83,7 +94,7 @@ internal extension NSManagedObjectContext {
                 let context = note.object as! NSManagedObjectContext
                 let insertedObjects = context.insertedObjects
                 let numberOfInsertedObjects = insertedObjects.count
-                if numberOfInsertedObjects <= 0 {
+                guard numberOfInsertedObjects > 0 else {
                     
                     return
                 }
@@ -91,7 +102,6 @@ internal extension NSManagedObjectContext {
                 do {
                     
                     try context.obtainPermanentIDsForObjects(Array(insertedObjects))
-                    return
                 }
                 catch {
                     

CoreStore/Internal/NSManagedObjectContext+Querying.swift

@@ -2,7 +2,7 @@
 //  NSManagedObjectContext+Querying.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -31,7 +31,43 @@ import CoreData
 
 internal extension NSManagedObjectContext {
     
-    // MARK: Public
+    // MARK: Internal
+    
+    internal func fetchExisting<T: NSManagedObject>(object: T) -> T? {
+        
+        if object.objectID.temporaryID {
+            
+            do {
+                
+                try withExtendedLifetime(self) { (context: NSManagedObjectContext) -> Void in
+                    
+                    try context.obtainPermanentIDsForObjects([object])
+                }
+            }
+            catch {
+                
+                CoreStore.handleError(
+                    error as NSError,
+                    "Failed to obtain permanent ID for object."
+                )
+                return nil
+            }
+        }
+        
+        do {
+            
+            let existingObject = try self.existingObjectWithID(object.objectID)
+            return (existingObject as! T)
+        }
+        catch {
+            
+            CoreStore.handleError(
+                error as NSError,
+                "Failed to load existing \(typeName(object)) in context."
+            )
+            return nil
+        }
+    }
     
     internal func fetchOne<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> T? {
         
@@ -40,7 +76,7 @@ internal extension NSManagedObjectContext {
     
     internal func fetchOne<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> T? {
         
-        let fetchRequest = NSFetchRequest()
+        let fetchRequest = CoreStoreFetchRequest()
         from.applyToFetchRequest(fetchRequest, context: self)
         
         fetchRequest.fetchLimit = 1
@@ -83,7 +119,7 @@ internal extension NSManagedObjectContext {
     
     internal func fetchAll<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> [T]? {
         
-        let fetchRequest = NSFetchRequest()
+        let fetchRequest = CoreStoreFetchRequest()
         from.applyToFetchRequest(fetchRequest, context: self)
         
         fetchRequest.fetchLimit = 0
@@ -126,7 +162,7 @@ internal extension NSManagedObjectContext {
     
     internal func fetchCount<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> Int? {
         
-        let fetchRequest = NSFetchRequest()
+        let fetchRequest = CoreStoreFetchRequest()
         from.applyToFetchRequest(fetchRequest, context: self)
         
         for clause in fetchClauses {
@@ -159,7 +195,7 @@ internal extension NSManagedObjectContext {
     
     internal func fetchObjectID<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> NSManagedObjectID? {
         
-        let fetchRequest = NSFetchRequest()
+        let fetchRequest = CoreStoreFetchRequest()
         from.applyToFetchRequest(fetchRequest, context: self)
         
         fetchRequest.fetchLimit = 1
@@ -202,7 +238,7 @@ internal extension NSManagedObjectContext {
     
     internal func fetchObjectIDs<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> [NSManagedObjectID]? {
         
-        let fetchRequest = NSFetchRequest()
+        let fetchRequest = CoreStoreFetchRequest()
         from.applyToFetchRequest(fetchRequest, context: self)
         
         fetchRequest.fetchLimit = 0
@@ -245,7 +281,7 @@ internal extension NSManagedObjectContext {
     
     internal func deleteAll<T: NSManagedObject>(from: From<T>, _ deleteClauses: [DeleteClause]) -> Int? {
         
-        let fetchRequest = NSFetchRequest()
+        let fetchRequest = CoreStoreFetchRequest()
         from.applyToFetchRequest(fetchRequest, context: self)
         
         fetchRequest.fetchLimit = 0
@@ -298,7 +334,7 @@ internal extension NSManagedObjectContext {
     
     internal func queryValue<T: NSManagedObject, U: SelectValueResultType>(from: From<T>, _ selectClause: Select<U>, _ queryClauses: [QueryClause]) -> U? {
         
-        let fetchRequest = NSFetchRequest()
+        let fetchRequest = CoreStoreFetchRequest()
         from.applyToFetchRequest(fetchRequest, context: self)
         
         fetchRequest.fetchLimit = 0
@@ -347,7 +383,7 @@ internal extension NSManagedObjectContext {
     
     internal func queryAttributes<T: NSManagedObject>(from: From<T>, _ selectClause: Select<NSDictionary>, _ queryClauses: [QueryClause]) -> [[NSString: AnyObject]]? {
         
-        let fetchRequest = NSFetchRequest()
+        let fetchRequest = CoreStoreFetchRequest()
         from.applyToFetchRequest(fetchRequest, context: self)
         
         fetchRequest.fetchLimit = 0

CoreStore/Internal/NSManagedObjectContext+Setup.swift

@@ -2,7 +2,7 @@
 //  NSManagedObjectContext+Setup.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -46,7 +46,7 @@ internal extension NSManagedObjectContext {
         }
         set {
             
-            if self.parentContext != nil {
+            guard self.parentContext == nil else {
                 
                 return
             }
@@ -82,9 +82,28 @@ internal extension NSManagedObjectContext {
             object: rootContext,
             closure: { [weak context] (note) -> Void in
                 
-                context?.performBlock { () -> Void in
+                guard let rootContext = note.object as? NSManagedObjectContext,
+                    let context = context else {
+                        
+                        return
+                }
+                let mergeChanges = { () -> Void in
                     
-                    context?.mergeChangesFromContextDidSaveNotification(note)
+                    let updatedObjects = (note.userInfo?[NSUpdatedObjectsKey] as? Set<NSManagedObject>) ?? []
+                    for object in updatedObjects {
+                        
+                        context.objectWithID(object.objectID).willAccessValueForKey(nil)
+                    }
+                    context.mergeChangesFromContextDidSaveNotification(note)
+                }
+                
+                if rootContext.isSavingSynchronously == true {
+                    
+                    context.performBlockAndWait(mergeChanges)
+                }
+                else {
+                    
+                    context.performBlock(mergeChanges)
                 }
             }
         )

CoreStore/Internal/NSManagedObjectContext+Transaction.swift

@@ -2,7 +2,7 @@
 //  NSManagedObjectContext+Transaction.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -25,7 +25,9 @@
 
 import Foundation
 import CoreData
-import GCDKit
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
 
 
 // MARK: - NSManagedObjectContext
@@ -53,6 +55,35 @@ internal extension NSManagedObjectContext {
         }
     }
     
+    internal var isSavingSynchronously: Bool? {
+        
+        get {
+            
+            let value: NSNumber? = getAssociatedObjectForKey(
+                &PropertyKeys.isSavingSynchronously,
+                inObject: self
+            )
+            return value?.boolValue
+        }
+        set {
+            
+            setAssociatedWeakObject(
+                newValue.flatMap { NSNumber(bool: $0) },
+                forKey: &PropertyKeys.isSavingSynchronously,
+                inObject: self
+            )
+        }
+    }
+    
+    internal func isRunningInAllowedQueue() -> Bool {
+        
+        guard let parentTransaction = self.parentTransaction else {
+            
+            return false
+        }
+        return parentTransaction.isRunningInAllowedQueue()
+    }
+    
     internal func temporaryContextInTransactionWithConcurrencyType(concurrencyType: NSManagedObjectContextConcurrencyType) -> NSManagedObjectContext {
         
         let context = NSManagedObjectContext(concurrencyType: concurrencyType)
@@ -69,16 +100,18 @@ internal extension NSManagedObjectContext {
         
         var result = SaveResult(hasChanges: false)
         
-        self.performBlockAndWait { [unowned self] () -> Void in
+        self.performBlockAndWait {
             
-            if !self.hasChanges {
+            guard self.hasChanges else {
                 
                 return
             }
             
             do {
                 
+                self.isSavingSynchronously = true
                 try self.save()
+                self.isSavingSynchronously = nil
             }
             catch {
                 
@@ -111,25 +144,24 @@ internal extension NSManagedObjectContext {
         return result
     }
     
-    internal func saveAsynchronouslyWithCompletion(completion: ((result: SaveResult) -> Void)?) {
+    internal func saveAsynchronouslyWithCompletion(completion: ((result: SaveResult) -> Void) = { _ in }) {
         
-        self.performBlock { () -> Void in
+        self.performBlock {
             
-            if !self.hasChanges {
+            guard self.hasChanges else {
                 
-                if let completion = completion {
+                GCDQueue.Main.async {
                     
-                    GCDQueue.Main.async {
-                        
-                        completion(result: SaveResult(hasChanges: false))
-                    }
+                    completion(result: SaveResult(hasChanges: false))
                 }
                 return
             }
             
             do {
                 
+                self.isSavingSynchronously = false
                 try self.save()
+                self.isSavingSynchronously = nil
             }
             catch {
                 
@@ -138,12 +170,9 @@ internal extension NSManagedObjectContext {
                     saveError,
                     "Failed to save \(typeName(NSManagedObjectContext))."
                 )
-                if let completion = completion {
+                GCDQueue.Main.async {
                     
-                    GCDQueue.Main.async {
-                        
-                        completion(result: SaveResult(saveError))
-                    }
+                    completion(result: SaveResult(saveError))
                 }
                 return
             }
@@ -152,7 +181,7 @@ internal extension NSManagedObjectContext {
                 
                 parentContext.saveAsynchronouslyWithCompletion(completion)
             }
-            else if let completion = completion {
+            else {
                 
                 GCDQueue.Main.async {
                     
@@ -162,11 +191,24 @@ internal extension NSManagedObjectContext {
         }
     }
     
+    internal func refreshAndMergeAllObjects() {
+        
+        if #available(iOS 8.3, OSX 10.11, *) {
+            
+            self.refreshAllObjects()
+        }
+        else {
+            
+            self.registeredObjects.forEach { self.refreshObject($0, mergeChanges: true) }
+        }
+    }
+    
     
     // MARK: Private
     
     private struct PropertyKeys {
         
         static var parentTransaction: Void?
+        static var isSavingSynchronously: Void?
     }
 }

CoreStore/Internal/NSManagedObjectModel+Setup.swift

@@ -2,7 +2,7 @@
 //  NSManagedObjectModel+Setup.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -65,10 +65,13 @@ internal extension NSManagedObjectModel {
         }
         else if let resolvedVersion = modelVersions.first ?? modelVersionHints.first {
             
-            CoreStore.log(
-                .Warning,
-                message: "The MigrationChain leaf versions do not include any of the model file's embedded versions. Resolving to version \"\(resolvedVersion)\"."
-            )
+            if !modelVersionHints.isEmpty {
+                
+                CoreStore.log(
+                    .Warning,
+                    message: "The MigrationChain leaf versions do not include any of the model file's embedded versions. Resolving to version \"\(resolvedVersion)\"."
+                )
+            }
             currentModelVersion = resolvedVersion
         }
         else {
@@ -150,6 +153,16 @@ internal extension NSManagedObjectModel {
         return self.entityNameMapping[NSStringFromClass(entityClass)]!
     }
     
+    @nonobjc internal func entityTypesMapping() -> [String: NSManagedObject.Type] {
+        
+        var mapping = [String: NSManagedObject.Type]()
+        self.entityNameMapping.forEach { (className, entityName) in
+            
+            mapping[entityName] = (NSClassFromString(className)! as! NSManagedObject.Type)
+        }
+        return mapping
+    }
+    
     @nonobjc internal func mergedModels() -> [NSManagedObjectModel] {
         
         return self.modelVersions?.map { self[$0] }.flatMap { $0 == nil ? [] : [$0!] } ?? [self]
@@ -183,14 +196,15 @@ internal extension NSManagedObjectModel {
     
     @nonobjc internal subscript(metadata: [String: AnyObject]) -> NSManagedObjectModel? {
         
-        if let modelHashes = metadata[NSStoreModelVersionHashesKey] as? [String : NSData] {
+        guard let modelHashes = metadata[NSStoreModelVersionHashesKey] as? [String : NSData] else {
             
-            for modelVersion in self.modelVersions ?? [] {
+            return nil
+        }
+        for modelVersion in self.modelVersions ?? [] {
+            
+            if let versionModel = self[modelVersion] where modelHashes == versionModel.entityVersionHashesByName {
                 
-                if let versionModel = self[modelVersion] where modelHashes == versionModel.entityVersionHashesByName {
-                    
-                    return versionModel
-                }
+                return versionModel
             }
         }
         return nil
@@ -236,15 +250,16 @@ internal extension NSManagedObjectModel {
                 return mapping as! [String: String]
             }
             
-            let mapping = self.entities.reduce([String: String]()) {
-                (var mapping, entityDescription) -> [String: String] in
+            var mapping = [String: String]()
+            self.entities.forEach {
                 
-                if let entityName = entityDescription.name {
+                guard let entityName = $0.name else {
                     
-                    let className = entityDescription.managedObjectClassName
-                    mapping[className] = entityName
+                    return
                 }
-                return mapping
+                
+                let className = $0.managedObjectClassName
+                mapping[className] = entityName
             }
             setAssociatedCopiedObject(
                 mapping as NSDictionary,

CoreStore/Internal/NSPersistentStoreCoordinator+Setup.swift

@@ -0,0 +1,80 @@
+//
+//  NSPersistentStoreCoordinator+Setup.swift
+//  CoreStore
+//
+//  Copyright © 2016 John Rommel Estropia. All rights reserved.
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+//
+
+import Foundation
+import CoreData
+
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
+
+
+// MARK: - NSPersistentStoreCoordinator
+
+internal extension NSPersistentStoreCoordinator {
+    
+    internal func performAsynchronously(closure: () -> Void) {
+        
+        #if USE_FRAMEWORKS
+            
+            self.performBlock(closure)
+        #else
+            
+            if #available(iOS 8.0, *) {
+                
+                self.performBlock(closure)
+            }
+            else {
+                
+                self.lock()
+                GCDQueue.Default.async {
+                    
+                    closure()
+                    self.unlock()
+                }
+            }
+        #endif
+    }
+    
+    internal func performSynchronously(closure: () -> Void) {
+        
+        #if USE_FRAMEWORKS
+            
+            self.performBlockAndWait(closure)
+        #else
+            
+            if #available(iOS 8.0, *) {
+                
+                self.performBlockAndWait(closure)
+            }
+            else {
+                
+                self.lock()
+                autoreleasepool(closure)
+                self.unlock()
+            }
+        #endif
+    }
+}

CoreStore/Internal/NotificationObserver.swift

@@ -2,7 +2,7 @@
 //  NotificationObserver.swift
 //  CoreStore
 //
-//  Copyright (c) 2014 John Rommel Estropia
+//  Copyright © 2014 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -36,14 +36,14 @@ internal final class NotificationObserver {
     let object: AnyObject?
     let observer: NSObjectProtocol
     
-    init(notificationName: String, object: AnyObject?, closure: (note: NSNotification) -> Void) {
+    init(notificationName: String, object: AnyObject?, queue: NSOperationQueue? = nil, closure: (note: NSNotification) -> Void) {
         
         self.notificationName = notificationName
         self.object = object
         self.observer = NSNotificationCenter.defaultCenter().addObserverForName(
             notificationName,
             object: object,
-            queue: nil,
+            queue: queue,
             usingBlock: closure
         )
     }

CoreStore/Internal/WeakObject.swift

@@ -2,7 +2,7 @@
 //  WeakObject.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal

CoreStore/Logging/CoreStore+Logging.swift

@@ -2,7 +2,7 @@
 //  CoreStore+Logging.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -30,8 +30,6 @@ import Foundation
 
 public extension CoreStore {
     
-    // MARK: Public
-    
     /**
     The `CoreStoreLogger` instance to be used. The default logger is an instance of a `DefaultLogger`.
     */
@@ -40,7 +38,7 @@ public extension CoreStore {
     
     // MARK: Internal
     
-    internal static func log(level: LogLevel, message: String, fileName: StaticString = __FILE__, lineNumber: Int = __LINE__, functionName: StaticString = __FUNCTION__) {
+    internal static func log(level: LogLevel, message: String, fileName: StaticString = #file, lineNumber: Int = #line, functionName: StaticString = #function) {
         
         self.logger.log(
             level: level,
@@ -51,7 +49,7 @@ public extension CoreStore {
         )
     }
     
-    internal static func handleError(error: NSError, _ message: String, fileName: StaticString = __FILE__, lineNumber: Int = __LINE__, functionName: StaticString = __FUNCTION__) {
+    internal static func handleError(error: NSError, _ message: String, fileName: StaticString = #file, lineNumber: Int = #line, functionName: StaticString = #function) {
         
         self.logger.handleError(
             error: error,
@@ -62,7 +60,7 @@ public extension CoreStore {
         )
     }
     
-    internal static func assert(@autoclosure condition: () -> Bool, _ message: String, fileName: StaticString = __FILE__, lineNumber: Int = __LINE__, functionName: StaticString = __FUNCTION__) {
+    internal static func assert(@autoclosure condition: () -> Bool, _ message: String, fileName: StaticString = #file, lineNumber: Int = #line, functionName: StaticString = #function) {
         
         self.logger.assert(
             condition,

CoreStore/Logging/CoreStoreLogger.swift

@@ -2,7 +2,7 @@
 //  CoreStoreLogger.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -29,8 +29,8 @@ import Foundation
 // MARK: - LogLevel
 
 /**
-The `LogLevel` indicates the severity of a log message.
-*/
+ The `LogLevel` indicates the severity of a log message.
+ */
 public enum LogLevel {
     
     case Trace
@@ -43,41 +43,41 @@ public enum LogLevel {
 // MARK: - CoreStoreLogger
 
 /**
-Custom loggers should implement the `CoreStoreLogger` protocol and pass its instance to `CoreStore.logger`. Calls to `log(...)`, `handleError(...)`, and `assert(...)` are not tied to a specific queue/thread, so it is the implementer's job to handle thread-safety.
-*/
+ Custom loggers should implement the `CoreStoreLogger` protocol and pass its instance to `CoreStore.logger`. Calls to `log(...)`, `handleError(...)`, and `assert(...)` are not tied to a specific queue/thread, so it is the implementer's job to handle thread-safety.
+ */
 public protocol CoreStoreLogger {
     
     /**
-    Handles log messages sent by the `CoreStore` framework.
-    
-    :level: the severity of the log message
-    :message: the log message
-    :fileName: the source file name
-    :lineNumber: the source line number
-    :functionName: the source function name
-    */
+     Handles log messages sent by the `CoreStore` framework.
+     
+     :level: the severity of the log message
+     :message: the log message
+     :fileName: the source file name
+     :lineNumber: the source line number
+     :functionName: the source function name
+     */
     func log(level level: LogLevel, message: String, fileName: StaticString, lineNumber: Int, functionName: StaticString)
     
     /**
-    Handles errors sent by the `CoreStore` framework.
-    
-    :error: the error
-    :message: the error message
-    :fileName: the source file name
-    :lineNumber: the source line number
-    :functionName: the source function name
-    */
+     Handles errors sent by the `CoreStore` framework.
+     
+     :error: the error
+     :message: the error message
+     :fileName: the source file name
+     :lineNumber: the source line number
+     :functionName: the source function name
+     */
     func handleError(error error: NSError, message: String, fileName: StaticString, lineNumber: Int, functionName: StaticString)
     
     /**
-    Handles assertions made throughout the `CoreStore` framework.
-    
-    :condition: the assertion condition
-    :message: the assertion message
-    :fileName: the source file name
-    :lineNumber: the source line number
-    :functionName: the source function name
-    */
+     Handles assertions made throughout the `CoreStore` framework.
+     
+     :condition: the assertion condition
+     :message: the assertion message
+     :fileName: the source file name
+     :lineNumber: the source line number
+     :functionName: the source function name
+     */
     func assert(@autoclosure condition: () -> Bool, message: String, fileName: StaticString, lineNumber: Int, functionName: StaticString)
 }
 
@@ -86,7 +86,7 @@ public protocol CoreStoreLogger {
 
 internal func typeName<T>(value: T) -> String {
     
-    return "'\(_stdlib_getDemangledTypeName(value))'"
+    return "'\(String(reflecting: value.dynamicType))'"
 }
 
 internal func typeName<T>(value: T.Type) -> String {
@@ -101,6 +101,5 @@ internal func typeName(value: AnyClass) -> String {
 
 internal func typeName(name: String?) -> String {
     
-    let typeName = name ?? "unknown"
-    return "<\(typeName)>"
+    return "<\(name ?? "unknown")>"
 }

CoreStore/Logging/DefaultLogger.swift

@@ -2,7 +2,7 @@
 //  DefaultLogger.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -29,12 +29,12 @@ import Foundation
 // MARK: - DefaultLogger
 
 /**
-The `DefaultLogger` is a basic implementation of the `CoreStoreLogger` protocol.
-
-- The `log(...)` method calls `print(...)` to print the level, source file name, line number, function name, and the log message.
-- The `handleError(...)` method calls `print(...)` to print the source file name, line number, function name, and the error message.
-- The `assert(...)` method calls `assert(...)` on the arguments.
-*/
+ The `DefaultLogger` is a basic implementation of the `CoreStoreLogger` protocol.
+ 
+ - The `log(...)` method calls `print(...)` to print the level, source file name, line number, function name, and the log message.
+ - The `handleError(...)` method calls `print(...)` to print the source file name, line number, function name, and the error message.
+ - The `assert(...)` method calls `assert(...)` on the arguments.
+ */
 public final class DefaultLogger: CoreStoreLogger {
     
     public init() { }
@@ -62,21 +62,26 @@ public final class DefaultLogger: CoreStoreLogger {
                 icon = "❗"
                 levelString = "Fatal"
             }
-            Swift.print("\(icon) [CoreStore: \(levelString)] \(fileName.stringValue.lastPathComponent):\(lineNumber) \(functionName)\n  ↪︎ \(message)\n")
+            Swift.print("\(icon) [CoreStore: \(levelString)] \((fileName.stringValue as NSString).lastPathComponent):\(lineNumber) \(functionName)\n  ↪︎ \(message)\n")
         #endif
     }
     
     public func handleError(error error: NSError, message: String, fileName: StaticString, lineNumber: Int, functionName: StaticString) {
         
         #if DEBUG
-            Swift.print("⚠️ [CoreStore: Error] \(fileName.stringValue.lastPathComponent):\(lineNumber) \(functionName)\n  ↪︎ \(message)\n    \(error)\n")
+            Swift.print("⚠️ [CoreStore: Error] \((fileName.stringValue as NSString).lastPathComponent):\(lineNumber) \(functionName)\n  ↪︎ \(message)\n    \(error)\n")
         #endif
     }
     
     public func assert(@autoclosure condition: () -> Bool, message: String, fileName: StaticString, lineNumber: Int, functionName: StaticString) {
         
         #if DEBUG
-            Swift.assert(condition, "❗ [CoreStore: Assertion Failure] \(message)", file: fileName, line: numericCast(lineNumber))
+            if condition() {
+                
+                return
+            }
+            Swift.print("❗ [CoreStore: Assertion Failure] \((fileName.stringValue as NSString).lastPathComponent):\(lineNumber) \(functionName)\n  ↪︎ \(message)\n")
+            Swift.fatalError()
         #endif
     }
 }

CoreStore/Migrating/CoreStore+Migration.swift

@@ -2,7 +2,7 @@
 //  CoreStore+Migration.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -25,7 +25,9 @@
 
 import Foundation
 import CoreData
-import GCDKit
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
 
 
 // MARK: - CoreStore
@@ -33,52 +35,56 @@ import GCDKit
 public extension CoreStore {
     
     /**
-    Asynchronously adds to the `defaultStack` an SQLite store from the given SQLite file name. Note that using `addSQLiteStore(...)` instead of `addSQLiteStoreAndWait(...)` implies that the migrations are allowed and expected (thus the asynchronous `completion`.)
-    
-    - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory. A new SQLite file will be created if it does not exist. Note that if you have multiple configurations, you will need to specify a different `fileName` explicitly for each of them.
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`, the "Default" configuration. Note that if you have multiple configurations, you will need to specify a different `fileName` explicitly for each of them.
-    - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.allBundles()`.
-    - parameter completion: the closure to be executed on the main queue when the process completes, either due to success or failure. The closure's `PersistentStoreResult` argument indicates the result. This closure is NOT executed if an error is thrown, but will be executed with a `.Failure` result if an error occurs asynchronously.
-    - returns: an `NSProgress` instance if a migration has started, or `nil` is no migrations are required
-    */
-    public static func addSQLiteStore(fileName fileName: String, configuration: String? = nil, mappingModelBundles: [NSBundle]? = nil, completion: (PersistentStoreResult) -> Void) throws -> NSProgress? {
+     Asynchronously adds to the `defaultStack` an SQLite store from the given SQLite file name. Note that using `addSQLiteStore(...)` instead of `addSQLiteStoreAndWait(...)` implies that the migrations are allowed and expected (thus the asynchronous `completion`.)
+     
+     - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory (or the "Caches" directory on tvOS). A new SQLite file will be created if it does not exist. Note that if you have multiple configurations, you will need to specify a different `fileName` explicitly for each of them.
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`, the "Default" configuration. Note that if you have multiple configurations, you will need to specify a different `fileName` explicitly for each of them.
+     - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.allBundles()`.
+     - parameter resetStoreOnModelMismatch: Set to true to delete the store on model mismatch; or set to false to report failure instead. Typically should only be set to true when debugging, or if the persistent store can be recreated easily. If not specified, defaults to false.
+     - parameter completion: the closure to be executed on the main queue when the process completes, either due to success or failure. The closure's `PersistentStoreResult` argument indicates the result. This closure is NOT executed if an error is thrown, but will be executed with a `.Failure` result if an error occurs asynchronously.
+     - returns: an `NSProgress` instance if a migration has started, or `nil` is no migrations are required
+     */
+    public static func addSQLiteStore(fileName fileName: String, configuration: String? = nil, mappingModelBundles: [NSBundle]? = nil, resetStoreOnModelMismatch: Bool = false, completion: (PersistentStoreResult) -> Void) throws -> NSProgress? {
         
         return try self.defaultStack.addSQLiteStore(
             fileName: fileName,
             configuration: configuration,
             mappingModelBundles: mappingModelBundles,
+            resetStoreOnModelMismatch: resetStoreOnModelMismatch,
             completion: completion
         )
     }
     
     /**
-    Asynchronously adds to the `defaultStack` an SQLite store from the given SQLite file URL. Note that using `addSQLiteStore(...)` instead of `addSQLiteStoreAndWait(...)` implies that the migrations are allowed and expected (thus the asynchronous `completion`.)
-    
-    - parameter fileURL: the local file URL for the SQLite persistent store. A new SQLite file will be created if it does not exist. If not specified, defaults to a file URL pointing to a "<Application name>.sqlite" file in the "Application Support" directory. Note that if you have multiple configurations, you will need to specify a different `fileURL` explicitly for each of them.
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`, the "Default" configuration. Note that if you have multiple configurations, you will need to specify a different `fileURL` explicitly for each of them.
-    - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.allBundles()`.
-    - parameter completion: the closure to be executed on the main queue when the process completes, either due to success or failure. The closure's `PersistentStoreResult` argument indicates the result. This closure is NOT executed if an error is thrown, but will be executed with a `.Failure` result if an error occurs asynchronously.
-    - returns: an `NSProgress` instance if a migration has started, or `nil` is no migrations are required
-    */
-    public static func addSQLiteStore(fileURL fileURL: NSURL = defaultSQLiteStoreURL, configuration: String? = nil, mappingModelBundles: [NSBundle]? = NSBundle.allBundles(), completion: (PersistentStoreResult) -> Void) throws -> NSProgress? {
+     Asynchronously adds to the `defaultStack` an SQLite store from the given SQLite file URL. Note that using `addSQLiteStore(...)` instead of `addSQLiteStoreAndWait(...)` implies that the migrations are allowed and expected (thus the asynchronous `completion`.)
+     
+     - parameter fileURL: the local file URL for the SQLite persistent store. A new SQLite file will be created if it does not exist. If not specified, defaults to a file URL pointing to a "<Application name>.sqlite" file in the "Application Support" directory (or the "Caches" directory on tvOS). Note that if you have multiple configurations, you will need to specify a different `fileURL` explicitly for each of them.
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`, the "Default" configuration. Note that if you have multiple configurations, you will need to specify a different `fileURL` explicitly for each of them.
+     - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.allBundles()`.
+     - parameter resetStoreOnModelMismatch: Set to true to delete the store on model mismatch; or set to false to report failure instead. Typically should only be set to true when debugging, or if the persistent store can be recreated easily. If not specified, defaults to false.
+     - parameter completion: the closure to be executed on the main queue when the process completes, either due to success or failure. The closure's `PersistentStoreResult` argument indicates the result. This closure is NOT executed if an error is thrown, but will be executed with a `.Failure` result if an error occurs asynchronously.
+     - returns: an `NSProgress` instance if a migration has started, or `nil` is no migrations are required
+     */
+    public static func addSQLiteStore(fileURL fileURL: NSURL = defaultSQLiteStoreURL, configuration: String? = nil, mappingModelBundles: [NSBundle]? = NSBundle.allBundles(), resetStoreOnModelMismatch: Bool = false, completion: (PersistentStoreResult) -> Void) throws -> NSProgress? {
         
         return try self.defaultStack.addSQLiteStore(
             fileURL: fileURL,
             configuration: configuration,
             mappingModelBundles: mappingModelBundles,
+            resetStoreOnModelMismatch: resetStoreOnModelMismatch,
             completion: completion
         )
     }
     
     /**
-    Using the `defaultStack`, migrates an SQLite store with the specified filename to the `DataStack`'s managed object model version WITHOUT adding the migrated store to the data stack.
-    
-    - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory.
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil` which indicates the "Default" configuration.
-    - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.mainBundle()`.
-    - parameter sourceBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.mainBundle()`.
-    - returns: an `NSProgress` instance if a migration has started, or `nil` is no migrations are required
-    */
+     Using the `defaultStack`, migrates an SQLite store with the specified filename to the `DataStack`'s managed object model version WITHOUT adding the migrated store to the data stack.
+     
+     - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory (or the "Caches" directory on tvOS).
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil` which indicates the "Default" configuration.
+     - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.mainBundle()`.
+     - parameter sourceBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.mainBundle()`.
+     - returns: an `NSProgress` instance if a migration has started, or `nil` is no migrations are required
+     */
     public static func upgradeSQLiteStoreIfNeeded(fileName fileName: String, configuration: String? = nil, mappingModelBundles: [NSBundle]? = nil, completion: (MigrationResult) -> Void) throws -> NSProgress? {
         
         return try self.defaultStack.upgradeSQLiteStoreIfNeeded(
@@ -90,14 +96,14 @@ public extension CoreStore {
     }
     
     /**
-    Using the `defaultStack`, migrates an SQLite store at the specified file URL and configuration name to the `DataStack`'s managed object model version. This method does NOT add the migrated store to the data stack.
-    
-    - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory.
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil` which indicates the "Default" configuration.
-    - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.mainBundle()`.
-    - parameter sourceBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.mainBundle()`.
-    - returns: an `NSProgress` instance if a migration has started, or `nil` is no migrations are required
-    */
+     Using the `defaultStack`, migrates an SQLite store at the specified file URL and configuration name to the `DataStack`'s managed object model version. This method does NOT add the migrated store to the data stack.
+     
+     - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory (or the "Caches" directory on tvOS).
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil` which indicates the "Default" configuration.
+     - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.mainBundle()`.
+     - parameter sourceBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.mainBundle()`.
+     - returns: an `NSProgress` instance if a migration has started, or `nil` is no migrations are required
+     */
     public static func upgradeSQLiteStoreIfNeeded(fileURL fileURL: NSURL = defaultSQLiteStoreURL, configuration: String? = nil, mappingModelBundles: [NSBundle]? = nil, completion: (MigrationResult) -> Void) throws -> NSProgress? {
         
         return try self.defaultStack.upgradeSQLiteStoreIfNeeded(
@@ -109,13 +115,14 @@ public extension CoreStore {
     }
     
     /**
-    Using the `defaultStack`, checks for the required migrations needed for the store with the specified filename and configuration to be migrated to the `DataStack`'s managed object model version. This method throws an error if the store does not exist, if inspection of the store failed, or no mapping model was found/inferred.
-    
-    - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory.
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil` which indicates the "Default" configuration.
-    - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.allBundles()`.
-    :return: an array of `MigrationType`s indicating the chain of migrations required for the store; or `nil` if either inspection of the store failed, or no mapping model was found/inferred. `MigrationType` acts as a `Bool` and evaluates to `false` if no migration is required, and `true` if either a lightweight or custom migration is needed.
-    */
+     Using the `defaultStack`, checks for the required migrations needed for the store with the specified filename and configuration to be migrated to the `DataStack`'s managed object model version. This method throws an error if the store does not exist, if inspection of the store failed, or no mapping model was found/inferred.
+     
+     - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory (or the "Caches" directory on tvOS).
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil` which indicates the "Default" configuration.
+     - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.allBundles()`.
+     :return: an array of `MigrationType`s indicating the chain of migrations required for the store; or `nil` if either inspection of the store failed, or no mapping model was found/inferred. `MigrationType` acts as a `Bool` and evaluates to `false` if no migration is required, and `true` if either a lightweight or custom migration is needed.
+     */
+    @warn_unused_result
     public static func requiredMigrationsForSQLiteStore(fileName fileName: String, configuration: String? = nil, mappingModelBundles: [NSBundle] = NSBundle.allBundles() as [NSBundle]) throws -> [MigrationType] {
         
         return try self.defaultStack.requiredMigrationsForSQLiteStore(
@@ -126,13 +133,14 @@ public extension CoreStore {
     }
     
     /**
-    Using the `defaultStack`, checks if the store at the specified file URL and configuration needs to be migrated to the `DataStack`'s managed object model version.
-    
-    - parameter fileURL: the local file URL for the SQLite persistent store.
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil` which indicates the "Default" configuration.
-    - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.allBundles()`.
-    :return: a `MigrationType` indicating the type of migration required for the store; or `nil` if either inspection of the store failed, or no mapping model was found/inferred. `MigrationType` acts as a `Bool` and evaluates to `false` if no migration is required, and `true` if either a lightweight or custom migration is needed.
-    */
+     Using the `defaultStack`, checks if the store at the specified file URL and configuration needs to be migrated to the `DataStack`'s managed object model version.
+     
+     - parameter fileURL: the local file URL for the SQLite persistent store.
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil` which indicates the "Default" configuration.
+     - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.allBundles()`.
+     :return: a `MigrationType` indicating the type of migration required for the store; or `nil` if either inspection of the store failed, or no mapping model was found/inferred. `MigrationType` acts as a `Bool` and evaluates to `false` if no migration is required, and `true` if either a lightweight or custom migration is needed.
+     */
+    @warn_unused_result
     public static func requiredMigrationsForSQLiteStore(fileURL fileURL: NSURL = defaultSQLiteStoreURL, configuration: String? = nil, mappingModelBundles: [NSBundle] = NSBundle.allBundles() as [NSBundle]) throws -> [MigrationType] {
         
         return try self.defaultStack.requiredMigrationsForSQLiteStore(

CoreStore/Migrating/DataStack+Migration.swift

@@ -2,7 +2,7 @@
 //  DataStack+Migration.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -25,7 +25,9 @@
 
 import Foundation
 import CoreData
-import GCDKit
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
 
 
 // MARK: - DataStack
@@ -33,14 +35,14 @@ import GCDKit
 public extension DataStack {
     
     /**
-    Asynchronously adds an in-memory store to the stack.
-    
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`.
-    - parameter completion: the closure to be executed on the main queue when the process completes, either due to success or failure. The closure's `PersistentStoreResult` argument indicates the result.
-    */
+     Asynchronously adds an in-memory store to the stack.
+     
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`.
+     - parameter completion: the closure to be executed on the main queue when the process completes, either due to success or failure. The closure's `PersistentStoreResult` argument indicates the result.
+     */
     public func addInMemoryStore(configuration configuration: String? = nil, completion: (PersistentStoreResult) -> Void) {
         
-        self.coordinator.performBlock {
+        self.coordinator.performAsynchronously {
             
             do {
                 
@@ -74,19 +76,19 @@ public extension DataStack {
     }
     
     /**
-    Asynchronously adds to the stack an SQLite store from the given SQLite file name. Note that using `addSQLiteStore(...)` instead of `addSQLiteStoreAndWait(...)` implies that the migrations are allowed and expected (thus the asynchronous `completion`.)
-    
-    - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory. A new SQLite file will be created if it does not exist. Note that if you have multiple configurations, you will need to specify a different `fileName` explicitly for each of them.
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`, the "Default" configuration. Note that if you have multiple configurations, you will need to specify a different `fileName` explicitly for each of them.
-    - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.allBundles()`.
-    - parameter resetStoreOnModelMismatch: Set to true to delete the store on model mismatch; or set to false to report failure instead. Typically should only be set to true when debugging, or if the persistent store can be recreated easily. If not specified, defaults to false.
-    - parameter completion: the closure to be executed on the main queue when the process completes, either due to success or failure. The closure's `PersistentStoreResult` argument indicates the result. This closure is NOT executed if an error is thrown, but will be executed with a `.Failure` result if an error occurs asynchronously.
-    - returns: an `NSProgress` instance if a migration has started, or `nil` is no migrations are required
-    */
+     Asynchronously adds to the stack an SQLite store from the given SQLite file name. Note that using `addSQLiteStore(...)` instead of `addSQLiteStoreAndWait(...)` implies that the migrations are allowed and expected (thus the asynchronous `completion`.)
+     
+     - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory (or the "Caches" directory on tvOS). A new SQLite file will be created if it does not exist. Note that if you have multiple configurations, you will need to specify a different `fileName` explicitly for each of them.
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`, the "Default" configuration. Note that if you have multiple configurations, you will need to specify a different `fileName` explicitly for each of them.
+     - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.allBundles()`.
+     - parameter resetStoreOnModelMismatch: Set to true to delete the store on model mismatch; or set to false to report failure instead. Typically should only be set to true when debugging, or if the persistent store can be recreated easily. If not specified, defaults to false.
+     - parameter completion: the closure to be executed on the main queue when the process completes, either due to success or failure. The closure's `PersistentStoreResult` argument indicates the result. This closure is NOT executed if an error is thrown, but will be executed with a `.Failure` result if an error occurs asynchronously.
+     - returns: an `NSProgress` instance if a migration has started, or `nil` is no migrations are required
+     */
     public func addSQLiteStore(fileName fileName: String, configuration: String? = nil, mappingModelBundles: [NSBundle]? = nil, resetStoreOnModelMismatch: Bool = false, completion: (PersistentStoreResult) -> Void) throws -> NSProgress? {
         
         return try self.addSQLiteStore(
-            fileURL: applicationSupportDirectory.URLByAppendingPathComponent(
+            fileURL: defaultDirectory.URLByAppendingPathComponent(
                 fileName,
                 isDirectory: false
             ),
@@ -98,15 +100,15 @@ public extension DataStack {
     }
     
     /**
-    Asynchronously adds to the stack an SQLite store from the given SQLite file URL. Note that using `addSQLiteStore(...)` instead of `addSQLiteStoreAndWait(...)` implies that the migrations are allowed and expected (thus the asynchronous `completion`.)
-    
-    - parameter fileURL: the local file URL for the SQLite persistent store. A new SQLite file will be created if it does not exist. If not specified, defaults to a file URL pointing to a "<Application name>.sqlite" file in the "Application Support" directory. Note that if you have multiple configurations, you will need to specify a different `fileURL` explicitly for each of them.
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`, the "Default" configuration. Note that if you have multiple configurations, you will need to specify a different `fileURL` explicitly for each of them.
-    - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.allBundles()`.
-    - parameter resetStoreOnModelMismatch: Set to true to delete the store on model mismatch; or set to false to report failure instead. Typically should only be set to true when debugging, or if the persistent store can be recreated easily. If not specified, defaults to false.
-    - parameter completion: the closure to be executed on the main queue when the process completes, either due to success or failure. The closure's `PersistentStoreResult` argument indicates the result. This closure is NOT executed if an error is thrown, but will be executed with a `.Failure` result if an error occurs asynchronously.
-    - returns: an `NSProgress` instance if a migration has started, or `nil` is no migrations are required
-    */
+     Asynchronously adds to the stack an SQLite store from the given SQLite file URL. Note that using `addSQLiteStore(...)` instead of `addSQLiteStoreAndWait(...)` implies that the migrations are allowed and expected (thus the asynchronous `completion`.)
+     
+     - parameter fileURL: the local file URL for the SQLite persistent store. A new SQLite file will be created if it does not exist. If not specified, defaults to a file URL pointing to a "<Application name>.sqlite" file in the "Application Support" directory (or the "Caches" directory on tvOS). Note that if you have multiple configurations, you will need to specify a different `fileURL` explicitly for each of them.
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`, the "Default" configuration. Note that if you have multiple configurations, you will need to specify a different `fileURL` explicitly for each of them.
+     - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.allBundles()`.
+     - parameter resetStoreOnModelMismatch: Set to true to delete the store on model mismatch; or set to false to report failure instead. Typically should only be set to true when debugging, or if the persistent store can be recreated easily. If not specified, defaults to false.
+     - parameter completion: the closure to be executed on the main queue when the process completes, either due to success or failure. The closure's `PersistentStoreResult` argument indicates the result. This closure is NOT executed if an error is thrown, but will be executed with a `.Failure` result if an error occurs asynchronously.
+     - returns: an `NSProgress` instance if a migration has started, or `nil` is no migrations are required
+     */
     public func addSQLiteStore(fileURL fileURL: NSURL = defaultSQLiteStoreURL, configuration: String? = nil, mappingModelBundles: [NSBundle]? = NSBundle.allBundles(), resetStoreOnModelMismatch: Bool = false, completion: (PersistentStoreResult) -> Void) throws -> NSProgress? {
         
         CoreStore.assert(
@@ -117,40 +119,37 @@ public extension DataStack {
         let coordinator = self.coordinator;
         if let store = coordinator.persistentStoreForURL(fileURL) {
             
-            if store.type == NSSQLiteStoreType
-                && store.configurationName == (configuration ?? Into.defaultConfigurationName) {
+            guard store.type == NSSQLiteStoreType
+                && store.configurationName == (configuration ?? Into.defaultConfigurationName) else {
                     
-                    GCDQueue.Main.async {
-                        
-                        completion(PersistentStoreResult(store))
-                    }
-                    return nil
+                    let error = NSError(coreStoreErrorCode: .DifferentPersistentStoreExistsAtURL)
+                    CoreStore.handleError(
+                        error,
+                        "Failed to add SQLite \(typeName(NSPersistentStore)) at \"\(fileURL)\" because a different \(typeName(NSPersistentStore)) at that URL already exists."
+                    )
+                    throw error
             }
             
-            let error = NSError(coreStoreErrorCode: .DifferentPersistentStoreExistsAtURL)
-            CoreStore.handleError(
-                error,
-                "Failed to add SQLite \(typeName(NSPersistentStore)) at \"\(fileURL)\" because a different \(typeName(NSPersistentStore)) at that URL already exists."
-            )
-            throw error
+            GCDQueue.Main.async {
+                
+                completion(PersistentStoreResult(store))
+            }
+            return nil
         }
         
         let fileManager = NSFileManager.defaultManager()
-        do {
-            
-            try fileManager.createDirectoryAtURL(
-                fileURL.URLByDeletingLastPathComponent!,
-                withIntermediateDirectories: true,
-                attributes: nil
-            )
-        }
-        catch _ { }
+        _ = try? fileManager.createDirectoryAtURL(
+            fileURL.URLByDeletingLastPathComponent!,
+            withIntermediateDirectories: true,
+            attributes: nil
+        )
         
         do {
             
             let metadata = try NSPersistentStoreCoordinator.metadataForPersistentStoreOfType(
                 NSSQLiteStoreType,
-                URL: fileURL
+                URL: fileURL,
+                options: self.optionsForSQLiteStore()
             )
             
             return self.upgradeSQLiteStoreIfNeeded(
@@ -232,18 +231,18 @@ public extension DataStack {
     }
     
     /**
-    Migrates an SQLite store with the specified filename to the `DataStack`'s managed object model version WITHOUT adding the migrated store to the data stack.
-    
-    - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory.
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil` which indicates the "Default" configuration.
-    - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.mainBundle()`.
-    - parameter sourceBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.mainBundle()`.
-    - returns: an `NSProgress` instance if a migration has started, or `nil` is no migrations are required
-    */
+     Migrates an SQLite store with the specified filename to the `DataStack`'s managed object model version WITHOUT adding the migrated store to the data stack.
+     
+     - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory (or the "Caches" directory on tvOS).
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil` which indicates the "Default" configuration.
+     - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.mainBundle()`.
+     - parameter sourceBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.mainBundle()`.
+     - returns: an `NSProgress` instance if a migration has started, or `nil` is no migrations are required
+     */
     public func upgradeSQLiteStoreIfNeeded(fileName fileName: String, configuration: String? = nil, mappingModelBundles: [NSBundle]? = nil, completion: (MigrationResult) -> Void) throws -> NSProgress? {
         
         return try self.upgradeSQLiteStoreIfNeeded(
-            fileURL: applicationSupportDirectory.URLByAppendingPathComponent(
+            fileURL: defaultDirectory.URLByAppendingPathComponent(
                 fileName,
                 isDirectory: false
             ),
@@ -254,14 +253,14 @@ public extension DataStack {
     }
     
     /**
-    Migrates an SQLite store at the specified file URL and configuration name to the `DataStack`'s managed object model version. This method does NOT add the migrated store to the data stack.
-    
-    - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory.
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil` which indicates the "Default" configuration.
-    - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.mainBundle()`.
-    - parameter sourceBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.mainBundle()`.
-    - returns: an `NSProgress` instance if a migration has started, or `nil` is no migrations are required
-    */
+     Migrates an SQLite store at the specified file URL and configuration name to the `DataStack`'s managed object model version. This method does NOT add the migrated store to the data stack.
+     
+     - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory (or the "Caches" directory on tvOS).
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil` which indicates the "Default" configuration.
+     - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.mainBundle()`.
+     - parameter sourceBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.mainBundle()`.
+     - returns: an `NSProgress` instance if a migration has started, or `nil` is no migrations are required
+     */
     public func upgradeSQLiteStoreIfNeeded(fileURL fileURL: NSURL = defaultSQLiteStoreURL, configuration: String? = nil, mappingModelBundles: [NSBundle]? = nil, completion: (MigrationResult) -> Void) throws -> NSProgress? {
         
         let metadata: [String: AnyObject]
@@ -269,7 +268,8 @@ public extension DataStack {
             
             metadata = try NSPersistentStoreCoordinator.metadataForPersistentStoreOfType(
                 NSSQLiteStoreType,
-                URL: fileURL
+                URL: fileURL,
+                options: self.optionsForSQLiteStore()
             )
         }
         catch {
@@ -291,17 +291,18 @@ public extension DataStack {
     }
     
     /**
-    Checks for the required migrations needed for the store with the specified filename and configuration to be migrated to the `DataStack`'s managed object model version. This method throws an error if the store does not exist, if inspection of the store failed, or no mapping model was found/inferred.
-    
-    - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory.
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil` which indicates the "Default" configuration.
-    - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.allBundles()`.
-    :return: an array of `MigrationType`s indicating the chain of migrations required for the store; or `nil` if either inspection of the store failed, or no mapping model was found/inferred. `MigrationType` acts as a `Bool` and evaluates to `false` if no migration is required, and `true` if either a lightweight or custom migration is needed.
-    */
+     Checks for the required migrations needed for the store with the specified filename and configuration to be migrated to the `DataStack`'s managed object model version. This method throws an error if the store does not exist, if inspection of the store failed, or no mapping model was found/inferred.
+     
+     - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory (or the "Caches" directory on tvOS).
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil` which indicates the "Default" configuration.
+     - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.allBundles()`.
+     :return: an array of `MigrationType`s indicating the chain of migrations required for the store; or `nil` if either inspection of the store failed, or no mapping model was found/inferred. `MigrationType` acts as a `Bool` and evaluates to `false` if no migration is required, and `true` if either a lightweight or custom migration is needed.
+     */
+    @warn_unused_result
     public func requiredMigrationsForSQLiteStore(fileName fileName: String, configuration: String? = nil, mappingModelBundles: [NSBundle] = NSBundle.allBundles() as [NSBundle]) throws -> [MigrationType] {
         
         return try requiredMigrationsForSQLiteStore(
-            fileURL: applicationSupportDirectory.URLByAppendingPathComponent(
+            fileURL: defaultDirectory.URLByAppendingPathComponent(
                 fileName,
                 isDirectory: false
             ),
@@ -311,13 +312,14 @@ public extension DataStack {
     }
     
     /**
-    Checks if the store at the specified file URL and configuration needs to be migrated to the `DataStack`'s managed object model version.
-    
-    - parameter fileURL: the local file URL for the SQLite persistent store.
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil` which indicates the "Default" configuration.
-    - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.allBundles()`.
-    :return: a `MigrationType` indicating the type of migration required for the store; or `nil` if either inspection of the store failed, or no mapping model was found/inferred. `MigrationType` acts as a `Bool` and evaluates to `false` if no migration is required, and `true` if either a lightweight or custom migration is needed.
-    */
+     Checks if the store at the specified file URL and configuration needs to be migrated to the `DataStack`'s managed object model version.
+     
+     - parameter fileURL: the local file URL for the SQLite persistent store.
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil` which indicates the "Default" configuration.
+     - parameter mappingModelBundles: an optional array of bundles to search mapping model files from. If not set, defaults to the `NSBundle.allBundles()`.
+     :return: a `MigrationType` indicating the type of migration required for the store; or `nil` if either inspection of the store failed, or no mapping model was found/inferred. `MigrationType` acts as a `Bool` and evaluates to `false` if no migration is required, and `true` if either a lightweight or custom migration is needed.
+     */
+    @warn_unused_result
     public func requiredMigrationsForSQLiteStore(fileURL fileURL: NSURL = defaultSQLiteStoreURL, configuration: String? = nil, mappingModelBundles: [NSBundle] = NSBundle.allBundles() as [NSBundle]) throws -> [MigrationType] {
         
         let metadata: [String : AnyObject]
@@ -325,7 +327,8 @@ public extension DataStack {
             
             metadata = try NSPersistentStoreCoordinator.metadataForPersistentStoreOfType(
                 NSSQLiteStoreType,
-                URL: fileURL
+                URL: fileURL,
+                options: self.optionsForSQLiteStore()
             )
         }
         catch {
@@ -435,8 +438,17 @@ public extension DataStack {
         }
         
         let migrationOperation = NSBlockOperation()
-        migrationOperation.qualityOfService = .Utility
-        operations.map { migrationOperation.addDependency($0) }
+        #if USE_FRAMEWORKS
+            
+            migrationOperation.qualityOfService = .Utility
+        #else
+            
+            if #available(iOS 8.0, *) {
+                
+                migrationOperation.qualityOfService = .Utility
+            }
+        #endif
+        operations.forEach { migrationOperation.addDependency($0) }
         migrationOperation.addExecutionBlock { () -> Void in
             
             GCDQueue.Main.async {

CoreStore/Migrating/MigrationChain.swift

@@ -2,7 +2,7 @@
 //  MigrationChain.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -30,36 +30,36 @@ import CoreData
 // MARK: - MigrationChain
 
 /**
-A `MigrationChain` indicates the sequence of model versions to be used as the order for incremental migration. This is typically passed to the `DataStack` initializer and will be applied to all stores added to the `DataStack` with `addSQLiteStore(...)` and its variants.
-
-Initializing with empty values (either `nil`, `[]`, or `[:]`) instructs the `DataStack` to use the .xcdatamodel's current version as the final version, and to disable incremental migrations:
-
-    let dataStack = DataStack(migrationChain: nil)
-
-This means that the mapping model will be computed from the store's version straight to the `DataStack`'s model version.
-To support incremental migrations, specify the linear order of versions:
-
-    let dataStack = DataStack(migrationChain: 
-        ["MyAppModel", "MyAppModelV2", "MyAppModelV3", "MyAppModelV4"])
-
-or for more complex migration paths, a version tree that maps the key-values to the source-destination versions:
-
-    let dataStack = DataStack(migrationChain: [
-        "MyAppModel": "MyAppModelV3",
-        "MyAppModelV2": "MyAppModelV4",
-        "MyAppModelV3": "MyAppModelV4"
-    ])
-
-This allows for different migration paths depending on the starting version. The example above resolves to the following paths:
-- MyAppModel-MyAppModelV3-MyAppModelV4
-- MyAppModelV2-MyAppModelV4
-- MyAppModelV3-MyAppModelV4
-
-The `MigrationChain` is validated when passed to the `DataStack` and unless it is empty, will raise an assertion if any of the following conditions are met:
-- a version appears twice in an array
-- a version appears twice as a key in a dictionary literal
-- a loop is found in any of the paths
-*/
+ A `MigrationChain` indicates the sequence of model versions to be used as the order for progressive migrations. This is typically passed to the `DataStack` initializer and will be applied to all stores added to the `DataStack` with `addSQLiteStore(...)` and its variants.
+ 
+ Initializing with empty values (either `nil`, `[]`, or `[:]`) instructs the `DataStack` to use the .xcdatamodel's current version as the final version, and to disable progressive migrations:
+ ```
+ let dataStack = DataStack(migrationChain: nil)
+ ```
+ This means that the mapping model will be computed from the store's version straight to the `DataStack`'s model version.
+ To support progressive migrations, specify the linear order of versions:
+ ```
+ let dataStack = DataStack(migrationChain:
+    ["MyAppModel", "MyAppModelV2", "MyAppModelV3", "MyAppModelV4"])
+ ```
+ or for more complex migration paths, a version tree that maps the key-values to the source-destination versions:
+ ```
+ let dataStack = DataStack(migrationChain: [
+     "MyAppModel": "MyAppModelV3",
+     "MyAppModelV2": "MyAppModelV4",
+     "MyAppModelV3": "MyAppModelV4"
+ ])
+ ```
+ This allows for different migration paths depending on the starting version. The example above resolves to the following paths:
+ - MyAppModel-MyAppModelV3-MyAppModelV4
+ - MyAppModelV2-MyAppModelV4
+ - MyAppModelV3-MyAppModelV4
+ 
+ The `MigrationChain` is validated when passed to the `DataStack` and unless it is empty, will raise an assertion if any of the following conditions are met:
+ - a version appears twice in an array
+ - a version appears twice as a key in a dictionary literal
+ - a loop is found in any of the paths
+ */
 public struct MigrationChain: NilLiteralConvertible, StringLiteralConvertible, DictionaryLiteralConvertible, ArrayLiteralConvertible {
     
     // MARK: NilLiteralConvertible
@@ -111,22 +111,24 @@ public struct MigrationChain: NilLiteralConvertible, StringLiteralConvertible, D
     public init(dictionaryLiteral elements: (String, String)...) {
         
         var valid = true
-        let versionTree = elements.reduce([String: String]()) { (var versionTree, tuple: (String, String)) -> [String: String] in
+        var versionTree = [String: String]()
+        elements.forEach { (sourceVersion, destinationVersion) in
             
-            if let _ = versionTree.updateValue(tuple.1, forKey: tuple.0) {
+            guard let _ = versionTree.updateValue(destinationVersion, forKey: sourceVersion) else {
                 
-                CoreStore.assert(false, "\(typeName(MigrationChain))'s migration chain could not be created due to ambiguous version paths.")
-                
-                valid = false
+                return
             }
-            return versionTree
+            
+            CoreStore.assert(false, "\(typeName(MigrationChain))'s migration chain could not be created due to ambiguous version paths.")
+            
+            valid = false
         }
         let leafVersions = Set(
             elements.filter { (tuple: (String, String)) -> Bool in
                 
                 return versionTree[tuple.1] == nil
                 
-            }.map { $1 }
+                }.map { $1 }
         )
         
         let isVersionAmbiguous = { (start: String) -> Bool in
@@ -166,12 +168,10 @@ public struct MigrationChain: NilLiteralConvertible, StringLiteralConvertible, D
         var valid = true
         for version in elements {
             
-            if let lastVersion = lastVersion {
-                
-                if let _ = versionTree.updateValue(version, forKey: lastVersion) {
+            if let lastVersion = lastVersion,
+                let _ = versionTree.updateValue(version, forKey: lastVersion) {
                     
                     valid = false
-                }
             }
             lastVersion = version
         }
@@ -203,11 +203,11 @@ public struct MigrationChain: NilLiteralConvertible, StringLiteralConvertible, D
     
     internal func nextVersionFrom(version: String) -> String? {
         
-        if let nextVersion = self.versionTree[version] where nextVersion != version {
+        guard let nextVersion = self.versionTree[version] where nextVersion != version else {
             
-            return nextVersion
+            return nil
         }
-        return nil
+        return nextVersion
     }
     
     
@@ -237,9 +237,9 @@ extension MigrationChain: CustomDebugStringConvertible {
                 steps.append(nextVersion)
                 version = nextVersion
             }
-            paths.append(" → ".join(steps))
+            paths.append(steps.joinWithSeparator(" → "))
         }
         
-        return "[" + "], [".join(paths) + "]"
+        return "[" + paths.joinWithSeparator("], [") + "]"
     }
 }

CoreStore/Migrating/MigrationResult.swift

@@ -2,7 +2,7 @@
 //  MigrationResult.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -29,46 +29,44 @@ import Foundation
 // MARK: - MigrationResult
 
 /**
-The `MigrationResult` indicates the result of a migration.
-The `MigrationResult` can be treated as a boolean:
-
-    CoreStore.upgradeSQLiteStoreIfNeeded { transaction in
-        // ...
-        let result = transaction.commit()
-        if result {
-            // succeeded
-        }
-        else {
-            // failed
-        }
-    }
-
-or as an `enum`, where the resulting associated object can also be inspected:
-
-    CoreStore.beginAsynchronous { transaction in
-        // ...
-        let result = transaction.commit()
-        switch result {
-        case .Success(let hasChanges):
-            // hasChanges indicates if there were changes or not
-        case .Failure(let error):
-            // error is the NSError instance for the failure
-        }
-    }
-```
-*/
+ The `MigrationResult` indicates the result of a migration.
+ The `MigrationResult` can be treated as a boolean:
+ ```
+ CoreStore.upgradeSQLiteStoreIfNeeded { transaction in
+     // ...
+     let result = transaction.commit()
+     if result {
+         // succeeded
+     }
+     else {
+         // failed
+     }
+ }
+ ```
+ or as an `enum`, where the resulting associated object can also be inspected:
+ ```
+ CoreStore.beginAsynchronous { transaction in
+     // ...
+     let result = transaction.commit()
+     switch result {
+     case .Success(let hasChanges):
+         // hasChanges indicates if there were changes or not
+     case .Failure(let error):
+         // error is the NSError instance for the failure
+     }
+ }
+ ```
+ */
 public enum MigrationResult {
     
-    // MARK: Public
-    
     /**
-    `MigrationResult.Success` indicates either the migration succeeded, or there were no migrations needed. The associated value is an array of `MigrationType`s reflecting the migration steps completed.
-    */
+     `MigrationResult.Success` indicates either the migration succeeded, or there were no migrations needed. The associated value is an array of `MigrationType`s reflecting the migration steps completed.
+     */
     case Success([MigrationType])
     
     /**
-    `SaveResult.Failure` indicates that the migration failed. The associated object for this value is the related `NSError` instance.
-    */
+     `SaveResult.Failure` indicates that the migration failed. The associated object for this value is the related `NSError` instance.
+     */
     case Failure(NSError)
     
     
@@ -103,6 +101,7 @@ extension MigrationResult: BooleanType {
     public var boolValue: Bool {
         
         switch self {
+            
         case .Success: return true
         case .Failure: return false
         }

CoreStore/Migrating/MigrationType.swift

@@ -2,7 +2,7 @@
 //  MigrationType.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -29,30 +29,28 @@ import Foundation
 // MARK: - MigrationType
 
 /**
-The `MigrationType` specifies the type of migration required for a store.
-*/
+ The `MigrationType` specifies the type of migration required for a store.
+ */
 public enum MigrationType: BooleanType {
     
-    // MARK: Public
-    
     /**
-    Indicates that the persistent store matches the latest model version and no migration is needed
-    */
+     Indicates that the persistent store matches the latest model version and no migration is needed
+     */
     case None(version: String)
     
     /**
-    Indicates that the persistent store does not match the latest model version but Core Data can infer the mapping model, so a lightweight migration is needed
-    */
+     Indicates that the persistent store does not match the latest model version but Core Data can infer the mapping model, so a lightweight migration is needed
+     */
     case Lightweight(sourceVersion: String, destinationVersion: String)
     
     /**
-    Indicates that the persistent store does not match the latest model version and Core Data could not infer a mapping model, so a custom migration is needed
-    */
+     Indicates that the persistent store does not match the latest model version and Core Data could not infer a mapping model, so a custom migration is needed
+     */
     case Heavyweight(sourceVersion: String, destinationVersion: String)
     
     /**
-    Returns the source model version for the migration type. If no migration is required, `sourceVersion` will be equal to the `destinationVersion`.
-    */
+     Returns the source model version for the migration type. If no migration is required, `sourceVersion` will be equal to the `destinationVersion`.
+     */
     public var sourceVersion: String {
         
         switch self {
@@ -69,8 +67,8 @@ public enum MigrationType: BooleanType {
     }
     
     /**
-    Returns the destination model version for the migration type. If no migration is required, `destinationVersion` will be equal to the `sourceVersion`.
-    */
+     Returns the destination model version for the migration type. If no migration is required, `destinationVersion` will be equal to the `sourceVersion`.
+     */
     public var destinationVersion: String {
         
         switch self {
@@ -87,8 +85,8 @@ public enum MigrationType: BooleanType {
     }
     
     /**
-    Returns `true` if the `MigrationType` is a lightweight migration. Used as syntactic sugar.
-    */
+     Returns `true` if the `MigrationType` is a lightweight migration. Used as syntactic sugar.
+     */
     public var isLightweightMigration: Bool {
         
         if case .Lightweight = self {
@@ -99,8 +97,8 @@ public enum MigrationType: BooleanType {
     }
     
     /**
-    Returns `true` if the `MigrationType` is a heavyweight migration. Used as syntactic sugar.
-    */
+     Returns `true` if the `MigrationType` is a heavyweight migration. Used as syntactic sugar.
+     */
     public var isHeavyweightMigration: Bool {
         
         if case .Heavyweight = self {

CoreStore/NSError+CoreStore.swift

@@ -2,7 +2,7 @@
 //  NSError+CoreStore.swift
 //  CoreStore
 //
-//  Copyright (c) 2014 John Rommel Estropia
+//  Copyright © 2014 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -24,46 +24,50 @@
 //
 
 import Foundation
+import CoreData
+
+
+// MARK: - CoreStoreError
 
 /**
-The `NSError` error domain for `CoreStore`.
-*/
+ The `NSError` error domain for `CoreStore`.
+ */
 public let CoreStoreErrorDomain = "com.corestore.error"
 
 /**
-The `NSError` error codes for `CoreStoreErrorDomain`.
-*/
+ The `NSError` error codes for `CoreStoreErrorDomain`.
+ */
 public enum CoreStoreErrorCode: Int {
     
     /**
-    A failure occured because of an unknown error.
-    */
+     A failure occured because of an unknown error.
+     */
     case UnknownError
     
     /**
-    The `NSPersistentStore` could note be initialized because another store existed at the specified `NSURL`.
-    */
+     The `NSPersistentStore` could note be initialized because another store existed at the specified `NSURL`.
+     */
     case DifferentPersistentStoreExistsAtURL
     
     /**
-    The `NSPersistentStore` specified could not be found.
-    */
+     The `NSPersistentStore` specified could not be found.
+     */
     case PersistentStoreNotFound
     
     /**
-    An `NSMappingModel` could not be found for a specific source and destination model versions.
-    */
+     An `NSMappingModel` could not be found for a specific source and destination model versions.
+     */
     case MappingModelNotFound
 }
 
 
-// MARK: - NSError+CoreStore
+// MARK: - NSError
 
 public extension NSError {
-   
+    
     /**
-    If the error's domain is equal to `CoreStoreErrorDomain`, returns the associated `CoreStoreErrorCode`. For other domains, returns `nil`.
-    */
+     If the error's domain is equal to `CoreStoreErrorDomain`, returns the associated `CoreStoreErrorCode`. For other domains, returns `nil`.
+     */
     public var coreStoreErrorCode: CoreStoreErrorCode? {
         
         return (self.domain == CoreStoreErrorDomain

CoreStore/Observing/CoreStore+Observing.swift

@@ -2,7 +2,7 @@
 //  CoreStore+Observing.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -29,68 +29,122 @@ import CoreData
 
 // MARK: - CoreStore
 
+@available(OSX, unavailable)
 public extension CoreStore {
     
-    // MARK: Public
-    
     /**
-    Using the `defaultStack`, creates a `ObjectMonitor` for the specified `NSManagedObject`. Multiple `ObjectObserver`s may then register themselves to be notified when changes are made to the `NSManagedObject`.
-    
-    - parameter object: the `NSManagedObject` to observe changes from
-    - returns: a `ObjectMonitor` that monitors changes to `object`
-    */
+     Using the `defaultStack`, creates a `ObjectMonitor` for the specified `NSManagedObject`. Multiple `ObjectObserver`s may then register themselves to be notified when changes are made to the `NSManagedObject`.
+     
+     - parameter object: the `NSManagedObject` to observe changes from
+     - returns: a `ObjectMonitor` that monitors changes to `object`
+     */
+    @warn_unused_result
     public static func monitorObject<T: NSManagedObject>(object: T) -> ObjectMonitor<T> {
         
         return self.defaultStack.monitorObject(object)
     }
     
     /**
-    Using the `defaultStack`, creates a `ListMonitor` for a list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: a `ListMonitor` instance that monitors changes to the list
-    */
-    public static func monitorList<T: NSManagedObject>(from: From<T>, _ groupBy: GroupBy? = nil, _ queryClauses: FetchClause...) -> ListMonitor<T> {
+     Using the `defaultStack`, creates a `ListMonitor` for a list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: a `ListMonitor` instance that monitors changes to the list
+     */
+    @warn_unused_result
+    public static func monitorList<T: NSManagedObject>(from: From<T>, _ queryClauses: FetchClause...) -> ListMonitor<T> {
         
         return self.defaultStack.monitorList(from, queryClauses)
     }
     
     /**
-    Using the `defaultStack`, creates a `ListMonitor` for a list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: a `ListMonitor` instance that monitors changes to the list
-    */
-    public static func monitorList<T: NSManagedObject>(from: From<T>, _ groupBy: GroupBy? = nil, _ queryClauses: [FetchClause]) -> ListMonitor<T> {
+     Using the `defaultStack`, creates a `ListMonitor` for a list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: a `ListMonitor` instance that monitors changes to the list
+     */
+    @warn_unused_result
+    public static func monitorList<T: NSManagedObject>(from: From<T>, _ queryClauses: [FetchClause]) -> ListMonitor<T> {
         
         return self.defaultStack.monitorList(from, queryClauses)
     }
     
     /**
-    Using the `defaultStack`, creates a `ListMonitor` for a sectioned list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
+     Using the `defaultStack`, asynchronously creates a `ListMonitor` for a list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list. Since `NSFetchedResultsController` greedily locks the persistent store on initial fetch, you may prefer this method instead of the synchronous counterpart to avoid deadlocks while background updates/saves are being executed.
+     
+     - parameter createAsynchronously: the closure that receives the created `ListMonitor` instance
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     */
+    public static func monitorList<T: NSManagedObject>(createAsynchronously createAsynchronously: (ListMonitor<T>) -> Void, _ from: From<T>, _ fetchClauses: FetchClause...) {
+        
+        self.defaultStack.monitorList(createAsynchronously: createAsynchronously, from, fetchClauses)
+    }
     
-    - parameter from: a `From` clause indicating the entity type
-    - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections.
-    - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: a `ListMonitor` instance that monitors changes to the list
-    */
+    /**
+     Using the `defaultStack`, asynchronously creates a `ListMonitor` for a list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list. Since `NSFetchedResultsController` greedily locks the persistent store on initial fetch, you may prefer this method instead of the synchronous counterpart to avoid deadlocks while background updates/saves are being executed.
+     
+     - parameter createAsynchronously: the closure that receives the created `ListMonitor` instance
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     */
+    public static func monitorList<T: NSManagedObject>(createAsynchronously createAsynchronously: (ListMonitor<T>) -> Void, _ from: From<T>, _ fetchClauses: [FetchClause])  {
+        
+        self.defaultStack.monitorList(createAsynchronously: createAsynchronously, from, fetchClauses)
+    }
+    
+    /**
+     Using the `defaultStack`, creates a `ListMonitor` for a sectioned list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections.
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: a `ListMonitor` instance that monitors changes to the list
+     */
+    @warn_unused_result
     public static func monitorSectionedList<T: NSManagedObject>(from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: FetchClause...) -> ListMonitor<T> {
         
         return self.defaultStack.monitorSectionedList(from, sectionBy, fetchClauses)
     }
     
     /**
-    Using the `defaultStack`, creates a `ListMonitor` for a sectioned list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections.
-    - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: a `ListMonitor` instance that monitors changes to the list
-    */
+     Using the `defaultStack`, creates a `ListMonitor` for a sectioned list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections.
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: a `ListMonitor` instance that monitors changes to the list
+     */
+    @warn_unused_result
     public static func monitorSectionedList<T: NSManagedObject>(from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: [FetchClause]) -> ListMonitor<T> {
         
         return self.defaultStack.monitorSectionedList(from, sectionBy, fetchClauses)
     }
+    
+    /**
+     Using the `defaultStack`, asynchronously creates a `ListMonitor` for a sectioned list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list. Since `NSFetchedResultsController` greedily locks the persistent store on initial fetch, you may prefer this method instead of the synchronous counterpart to avoid deadlocks while background updates/saves are being executed.
+     
+     - parameter createAsynchronously: the closure that receives the created `ListMonitor` instance
+     - parameter from: a `From` clause indicating the entity type
+     - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections.
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     */
+    public static func monitorSectionedList<T: NSManagedObject>(createAsynchronously createAsynchronously: (ListMonitor<T>) -> Void, _ from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: FetchClause...) {
+        
+        self.defaultStack.monitorSectionedList(createAsynchronously: createAsynchronously, from, sectionBy, fetchClauses)
+    }
+    
+    /**
+     Using the `defaultStack`, asynchronously creates a `ListMonitor` for a sectioned list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list. Since `NSFetchedResultsController` greedily locks the persistent store on initial fetch, you may prefer this method instead of the synchronous counterpart to avoid deadlocks while background updates/saves are being executed.
+     
+     - parameter createAsynchronously: the closure that receives the created `ListMonitor` instance
+     - parameter from: a `From` clause indicating the entity type
+     - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections.
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     */
+    public static func monitorSectionedList<T: NSManagedObject>(createAsynchronously createAsynchronously: (ListMonitor<T>) -> Void, _ from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: [FetchClause]) {
+        
+        self.defaultStack.monitorSectionedList(createAsynchronously: createAsynchronously, from, sectionBy, fetchClauses)
+    }
 }

CoreStore/Observing/DataStack+Observing.swift

@@ -2,7 +2,7 @@
 //  DataStack+Observing.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -25,21 +25,23 @@
 
 import Foundation
 import CoreData
-import GCDKit
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
 
 
 // MARK: - DataStack
 
+@available(OSX, unavailable)
 public extension DataStack {
     
-    // MARK: Public
-    
     /**
-    Creates a `ObjectMonitor` for the specified `NSManagedObject`. Multiple `ObjectObserver`s may then register themselves to be notified when changes are made to the `NSManagedObject`.
-    
-    - parameter object: the `NSManagedObject` to observe changes from
-    - returns: a `ObjectMonitor` that monitors changes to `object`
-    */
+     Creates a `ObjectMonitor` for the specified `NSManagedObject`. Multiple `ObjectObserver`s may then register themselves to be notified when changes are made to the `NSManagedObject`.
+     
+     - parameter object: the `NSManagedObject` to observe changes from
+     - returns: a `ObjectMonitor` that monitors changes to `object`
+     */
+    @warn_unused_result
     public func monitorObject<T: NSManagedObject>(object: T) -> ObjectMonitor<T> {
         
         CoreStore.assert(
@@ -54,24 +56,26 @@ public extension DataStack {
     }
     
     /**
-    Creates a `ListMonitor` for a list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: a `ListMonitor` instance that monitors changes to the list
-    */
+     Creates a `ListMonitor` for a list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: a `ListMonitor` instance that monitors changes to the list
+     */
+    @warn_unused_result
     public func monitorList<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> ListMonitor<T> {
         
         return self.monitorList(from, fetchClauses)
     }
     
     /**
-    Creates a `ListMonitor` for a list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: a `ListMonitor` instance that monitors changes to the list
-    */
+     Creates a `ListMonitor` for a list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: a `ListMonitor` instance that monitors changes to the list
+     */
+    @warn_unused_result
     public func monitorList<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> ListMonitor<T> {
         
         CoreStore.assert(
@@ -92,26 +96,67 @@ public extension DataStack {
     }
     
     /**
-    Creates a `ListMonitor` for a sectioned list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections.
-    - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: a `ListMonitor` instance that monitors changes to the list
-    */
-    public func monitorSectionedList<T: NSManagedObject>(from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: FetchClause...) -> ListMonitor<T> {
+     Asynchronously creates a `ListMonitor` for a list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list. Since `NSFetchedResultsController` greedily locks the persistent store on initial fetch, you may prefer this method instead of the synchronous counterpart to avoid deadlocks while background updates/saves are being executed.
      
+     - parameter createAsynchronously: the closure that receives the created `ListMonitor` instance
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     */
+    public func monitorList<T: NSManagedObject>(createAsynchronously createAsynchronously: (ListMonitor<T>) -> Void, _ from: From<T>, _ fetchClauses: FetchClause...) {
+        
+        self.monitorList(createAsynchronously: createAsynchronously, from, fetchClauses)
+    }
+    
+    /**
+     Asynchronously creates a `ListMonitor` for a list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list. Since `NSFetchedResultsController` greedily locks the persistent store on initial fetch, you may prefer this method instead of the synchronous counterpart to avoid deadlocks while background updates/saves are being executed.
+     
+     - parameter createAsynchronously: the closure that receives the created `ListMonitor` instance
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     */
+    public func monitorList<T: NSManagedObject>(createAsynchronously createAsynchronously: (ListMonitor<T>) -> Void, _ from: From<T>, _ fetchClauses: [FetchClause])  {
+        
+        CoreStore.assert(
+            NSThread.isMainThread(),
+            "Attempted to observe objects from \(typeName(self)) outside the main thread."
+        )
+        CoreStore.assert(
+            fetchClauses.filter { $0 is OrderBy }.count > 0,
+            "A ListMonitor requires an OrderBy clause."
+        )
+        
+        _ = ListMonitor(
+            dataStack: self,
+            from: from,
+            sectionBy: nil,
+            fetchClauses: fetchClauses,
+            createAsynchronously: createAsynchronously
+        )
+    }
+    
+    /**
+     Creates a `ListMonitor` for a sectioned list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections.
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: a `ListMonitor` instance that monitors changes to the list
+     */
+    @warn_unused_result
+    public func monitorSectionedList<T: NSManagedObject>(from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: FetchClause...) -> ListMonitor<T> {
+        
         return self.monitorSectionedList(from, sectionBy, fetchClauses)
     }
     
     /**
-    Creates a `ListMonitor` for a sectioned list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
-    
-    - parameter from: a `From` clause indicating the entity type
-    - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections.
-    - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
-    - returns: a `ListMonitor` instance that monitors changes to the list
-    */
+     Creates a `ListMonitor` for a sectioned list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections.
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: a `ListMonitor` instance that monitors changes to the list
+     */
+    @warn_unused_result
     public func monitorSectionedList<T: NSManagedObject>(from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: [FetchClause]) -> ListMonitor<T> {
         
         CoreStore.assert(
@@ -130,4 +175,45 @@ public extension DataStack {
             fetchClauses: fetchClauses
         )
     }
+    
+    /**
+     Asynchronously creates a `ListMonitor` for a sectioned list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list. Since `NSFetchedResultsController` greedily locks the persistent store on initial fetch, you may prefer this method instead of the synchronous counterpart to avoid deadlocks while background updates/saves are being executed.
+     
+     - parameter createAsynchronously: the closure that receives the created `ListMonitor` instance
+     - parameter from: a `From` clause indicating the entity type
+     - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections.
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     */
+    public func monitorSectionedList<T: NSManagedObject>(createAsynchronously createAsynchronously: (ListMonitor<T>) -> Void, _ from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: FetchClause...) {
+        
+        self.monitorSectionedList(createAsynchronously: createAsynchronously, from, sectionBy, fetchClauses)
+    }
+    
+    /**
+     Asynchronously creates a `ListMonitor` for a sectioned list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list. Since `NSFetchedResultsController` greedily locks the persistent store on initial fetch, you may prefer this method instead of the synchronous counterpart to avoid deadlocks while background updates/saves are being executed.
+     
+     - parameter createAsynchronously: the closure that receives the created `ListMonitor` instance
+     - parameter from: a `From` clause indicating the entity type
+     - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections.
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     */
+    public func monitorSectionedList<T: NSManagedObject>(createAsynchronously createAsynchronously: (ListMonitor<T>) -> Void, _ from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: [FetchClause]) {
+        
+        CoreStore.assert(
+            NSThread.isMainThread(),
+            "Attempted to observe objects from \(typeName(self)) outside the main thread."
+        )
+        CoreStore.assert(
+            fetchClauses.filter { $0 is OrderBy }.count > 0,
+            "A ListMonitor requires an OrderBy clause."
+        )
+        
+        _ = ListMonitor(
+            dataStack: self,
+            from: from,
+            sectionBy: sectionBy,
+            fetchClauses: fetchClauses,
+            createAsynchronously: createAsynchronously
+        )
+    }
 }

CoreStore/Observing/ListObserver.swift

@@ -2,7 +2,7 @@
 //  ListObserver.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -30,118 +30,209 @@ import CoreData
 // MARK: - ListObserver
 
 /**
-Implement the `ListObserver` protocol to observe changes to a list of `NSManagedObject`s. `ListObserver`s may register themselves to a `ListMonitor`'s `addObserver(_:)` method:
-
-    let monitor = CoreStore.monitorList(
-        From(MyPersonEntity),
-        OrderBy(.Ascending("lastName"))
-    )
-    monitor.addObserver(self)
-*/
+ Implement the `ListObserver` protocol to observe changes to a list of `NSManagedObject`s. `ListObserver`s may register themselves to a `ListMonitor`'s `addObserver(_:)` method:
+ ```
+ let monitor = CoreStore.monitorList(
+     From(MyPersonEntity),
+     OrderBy(.Ascending("lastName"))
+ )
+ monitor.addObserver(self)
+ ```
+ */
+@available(OSX, unavailable)
 public protocol ListObserver: class {
     
     /**
-    The `NSManagedObject` type for the observed list
-    */
-    typealias EntityType: NSManagedObject
+     The `NSManagedObject` type for the observed list
+     */
+    associatedtype ListEntityType: NSManagedObject
     
     /**
-    Handles processing just before a change to the observed list occurs
-    
-    - parameter monitor: the `ListMonitor` monitoring the list being observed
-    */
-    func listMonitorWillChange(monitor: ListMonitor<EntityType>)
+     Handles processing just before a change to the observed list occurs
+     
+     - parameter monitor: the `ListMonitor` monitoring the list being observed
+     */
+    func listMonitorWillChange(monitor: ListMonitor<ListEntityType>)
     
     /**
-    Handles processing right after a change to the observed list occurs
+     Handles processing right after a change to the observed list occurs
+     
+     - parameter monitor: the `ListMonitor` monitoring the object being observed
+     */
+    func listMonitorDidChange(monitor: ListMonitor<ListEntityType>)
     
-    - parameter monitor: the `ListMonitor` monitoring the object being observed
-    */
-    func listMonitorDidChange(monitor: ListMonitor<EntityType>)
+    /**
+     This method is broadcast from within the `ListMonitor`'s `refetch(...)` method to let observers prepare for the internal `NSFetchedResultsController`'s pending change to its predicate, sort descriptors, etc. Note that the actual refetch will happen after the `NSFetchedResultsController`'s last `controllerDidChangeContent(_:)` notification completes.
+     
+     - parameter monitor: the `ListMonitor` monitoring the object being observed
+     */
+    func listMonitorWillRefetch(monitor: ListMonitor<ListEntityType>)
+    
+    /**
+     After the `ListMonitor`'s `refetch(...)` method is called, this method is broadcast after the `NSFetchedResultsController`'s last `controllerDidChangeContent(_:)` notification completes.
+     
+     - parameter monitor: the `ListMonitor` monitoring the object being observed
+     */
+    func listMonitorDidRefetch(monitor: ListMonitor<ListEntityType>)
+}
+
+
+// MARK: - ListObserver (Default Implementations)
+
+@available(OSX, unavailable)
+public extension ListObserver {
+    
+    /**
+     The default implementation does nothing.
+     */
+    func listMonitorWillChange(monitor: ListMonitor<ListEntityType>) { }
+    
+    /**
+     The default implementation does nothing.
+     */
+    func listMonitorDidChange(monitor: ListMonitor<ListEntityType>) { }
+    
+    /**
+     The default implementation does nothing.
+     */
+    func listMonitorWillRefetch(monitor: ListMonitor<ListEntityType>) { }
+    
+    /**
+     The default implementation does nothing.
+     */
+    func listMonitorDidRefetch(monitor: ListMonitor<ListEntityType>) { }
 }
 
 
 // MARK: - ListObjectObserver
 
 /**
-Implement the `ListObjectObserver` protocol to observe detailed changes to a list's object. `ListObjectObserver`s may register themselves to a `ListMonitor`'s `addObserver(_:)` method:
-
-    let monitor = CoreStore.monitorList(
-        From(MyPersonEntity),
-        OrderBy(.Ascending("lastName"))
-    )
-    monitor.addObserver(self)
-*/
+ Implement the `ListObjectObserver` protocol to observe detailed changes to a list's object. `ListObjectObserver`s may register themselves to a `ListMonitor`'s `addObserver(_:)` method:
+ ```
+ let monitor = CoreStore.monitorList(
+     From(MyPersonEntity),
+     OrderBy(.Ascending("lastName"))
+ )
+ monitor.addObserver(self)
+ ```
+ */
+@available(OSX, unavailable)
 public protocol ListObjectObserver: ListObserver {
     
     /**
-    Notifies that an object was inserted to the specified `NSIndexPath` in the list
-    
-    - parameter monitor: the `ListMonitor` monitoring the list being observed
-    - parameter object: the entity type for the inserted object
-    - parameter indexPath: the new `NSIndexPath` for the inserted object
-    */
-    func listMonitor(monitor: ListMonitor<EntityType>, didInsertObject object: EntityType, toIndexPath indexPath: NSIndexPath)
+     Notifies that an object was inserted to the specified `NSIndexPath` in the list
+     
+     - parameter monitor: the `ListMonitor` monitoring the list being observed
+     - parameter object: the entity type for the inserted object
+     - parameter indexPath: the new `NSIndexPath` for the inserted object
+     */
+    func listMonitor(monitor: ListMonitor<ListEntityType>, didInsertObject object: ListEntityType, toIndexPath indexPath: NSIndexPath)
     
     /**
-    Notifies that an object was deleted from the specified `NSIndexPath` in the list
-    
-    - parameter monitor: the `ListMonitor` monitoring the list being observed
-    - parameter object: the entity type for the deleted object
-    - parameter indexPath: the `NSIndexPath` for the deleted object
-    */
-    func listMonitor(monitor: ListMonitor<EntityType>, didDeleteObject object: EntityType, fromIndexPath indexPath: NSIndexPath)
+     Notifies that an object was deleted from the specified `NSIndexPath` in the list
+     
+     - parameter monitor: the `ListMonitor` monitoring the list being observed
+     - parameter object: the entity type for the deleted object
+     - parameter indexPath: the `NSIndexPath` for the deleted object
+     */
+    func listMonitor(monitor: ListMonitor<ListEntityType>, didDeleteObject object: ListEntityType, fromIndexPath indexPath: NSIndexPath)
     
     /**
-    Notifies that an object at the specified `NSIndexPath` was updated
-    
-    - parameter monitor: the `ListMonitor` monitoring the list being observed
-    - parameter object: the entity type for the updated object
-    - parameter indexPath: the `NSIndexPath` for the updated object
-    */
-    func listMonitor(monitor: ListMonitor<EntityType>, didUpdateObject object: EntityType, atIndexPath indexPath: NSIndexPath)
+     Notifies that an object at the specified `NSIndexPath` was updated
+     
+     - parameter monitor: the `ListMonitor` monitoring the list being observed
+     - parameter object: the entity type for the updated object
+     - parameter indexPath: the `NSIndexPath` for the updated object
+     */
+    func listMonitor(monitor: ListMonitor<ListEntityType>, didUpdateObject object: ListEntityType, atIndexPath indexPath: NSIndexPath)
     
     /**
-    Notifies that an object's index changed
+     Notifies that an object's index changed
+     
+     - parameter monitor: the `ListMonitor` monitoring the list being observed
+     - parameter object: the entity type for the moved object
+     - parameter fromIndexPath: the previous `NSIndexPath` for the moved object
+     - parameter toIndexPath: the new `NSIndexPath` for the moved object
+     */
+    func listMonitor(monitor: ListMonitor<ListEntityType>, didMoveObject object: ListEntityType, fromIndexPath: NSIndexPath, toIndexPath: NSIndexPath)
+}
+
+
+// MARK: - ListObjectObserver (Default Implementations)
+
+@available(OSX, unavailable)
+public extension ListObjectObserver {
     
-    - parameter monitor: the `ListMonitor` monitoring the list being observed
-    - parameter object: the entity type for the moved object
-    - parameter fromIndexPath: the previous `NSIndexPath` for the moved object
-    - parameter toIndexPath: the new `NSIndexPath` for the moved object
-    */
-    func listMonitor(monitor: ListMonitor<EntityType>, didMoveObject object: EntityType, fromIndexPath: NSIndexPath, toIndexPath: NSIndexPath)
+    /**
+     The default implementation does nothing.
+     */
+    func listMonitor(monitor: ListMonitor<ListEntityType>, didInsertObject object: ListEntityType, toIndexPath indexPath: NSIndexPath) { }
+    
+    /**
+     The default implementation does nothing.
+     */
+    func listMonitor(monitor: ListMonitor<ListEntityType>, didDeleteObject object: ListEntityType, fromIndexPath indexPath: NSIndexPath) { }
+    
+    /**
+     The default implementation does nothing.
+     */
+    func listMonitor(monitor: ListMonitor<ListEntityType>, didUpdateObject object: ListEntityType, atIndexPath indexPath: NSIndexPath) { }
+    
+    /**
+     The default implementation does nothing.
+     */
+    func listMonitor(monitor: ListMonitor<ListEntityType>, didMoveObject object: ListEntityType, fromIndexPath: NSIndexPath, toIndexPath: NSIndexPath) { }
 }
 
 
 // MARK: - ListSectionObserver
 
 /**
-Implement the `ListSectionObserver` protocol to observe changes to a list's section info. `ListSectionObserver`s may register themselves to a `ListMonitor`'s `addObserver(_:)` method:
-
-    let monitor = CoreStore.monitorSectionedList(
-        From(MyPersonEntity),
-        SectionBy("age") { "Age \($0)" },
-        OrderBy(.Ascending("lastName"))
-    )
-    monitor.addObserver(self)
-*/
+ Implement the `ListSectionObserver` protocol to observe changes to a list's section info. `ListSectionObserver`s may register themselves to a `ListMonitor`'s `addObserver(_:)` method:
+ ```
+ let monitor = CoreStore.monitorSectionedList(
+     From(MyPersonEntity),
+     SectionBy("age") { "Age \($0)" },
+     OrderBy(.Ascending("lastName"))
+ )
+ monitor.addObserver(self)
+ ```
+ */
+@available(OSX, unavailable)
 public protocol ListSectionObserver: ListObjectObserver {
     
     /**
-    Notifies that a section was inserted at the specified index
-    
-    - parameter monitor: the `ListMonitor` monitoring the list being observed
-    - parameter sectionInfo: the `NSFetchedResultsSectionInfo` for the inserted section
-    - parameter sectionIndex: the new section index for the new section
-    */
-    func listMonitor(monitor: ListMonitor<EntityType>, didInsertSection sectionInfo: NSFetchedResultsSectionInfo, toSectionIndex sectionIndex: Int)
+     Notifies that a section was inserted at the specified index
+     
+     - parameter monitor: the `ListMonitor` monitoring the list being observed
+     - parameter sectionInfo: the `NSFetchedResultsSectionInfo` for the inserted section
+     - parameter sectionIndex: the new section index for the new section
+     */
+    func listMonitor(monitor: ListMonitor<ListEntityType>, didInsertSection sectionInfo: NSFetchedResultsSectionInfo, toSectionIndex sectionIndex: Int)
     
     /**
-    Notifies that a section was inserted at the specified index
-    
-    - parameter monitor: the `ListMonitor` monitoring the list being observed
-    - parameter sectionInfo: the `NSFetchedResultsSectionInfo` for the deleted section
-    - parameter sectionIndex: the previous section index for the deleted section
-    */
-    func listMonitor(monitor: ListMonitor<EntityType>, didDeleteSection sectionInfo: NSFetchedResultsSectionInfo, fromSectionIndex sectionIndex: Int)
+     Notifies that a section was inserted at the specified index
+     
+     - parameter monitor: the `ListMonitor` monitoring the list being observed
+     - parameter sectionInfo: the `NSFetchedResultsSectionInfo` for the deleted section
+     - parameter sectionIndex: the previous section index for the deleted section
+     */
+    func listMonitor(monitor: ListMonitor<ListEntityType>, didDeleteSection sectionInfo: NSFetchedResultsSectionInfo, fromSectionIndex sectionIndex: Int)
+}
+
+
+// MARK: - ListSectionObserver (Default Implementations)
+
+@available(OSX, unavailable)
+public extension ListSectionObserver {
+    
+    /**
+     The default implementation does nothing.
+     */
+    func listMonitor(monitor: ListMonitor<ListEntityType>, didInsertSection sectionInfo: NSFetchedResultsSectionInfo, toSectionIndex sectionIndex: Int) { }
+    
+    /**
+     The default implementation does nothing.
+     */
+    func listMonitor(monitor: ListMonitor<ListEntityType>, didDeleteSection sectionInfo: NSFetchedResultsSectionInfo, fromSectionIndex sectionIndex: Int) { }
 }

CoreStore/Observing/ObjectMonitor.swift

@@ -2,7 +2,7 @@
 //  ObjectMonitor.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -25,67 +25,54 @@
 
 import Foundation
 import CoreData
-import GCDKit
-
-
-private let ObjectMonitorWillChangeObjectNotification = "ObjectMonitorWillChangeObjectNotification"
-private let ObjectMonitorDidDeleteObjectNotification = "ObjectMonitorDidDeleteObjectNotification"
-private let ObjectMonitorDidUpdateObjectNotification = "ObjectMonitorDidUpdateObjectNotification"
-
-private let UserInfoKeyObject = "UserInfoKeyObject"
-
-private struct NotificationKey {
-    
-    static var willChangeObject: Void?
-    static var didDeleteObject: Void?
-    static var didUpdateObject: Void?
-}
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
 
 
 // MARK: - ObjectMonitor
 
 /**
-The `ObjectMonitor` monitors changes to a single `NSManagedObject` instance. Observers that implement the `ObjectObserver` protocol may then register themselves to the `ObjectMonitor`'s `addObserver(_:)` method:
-
-    let monitor = CoreStore.monitorObject(object)
-    monitor.addObserver(self)
-
-The created `ObjectMonitor` instance needs to be held on (retained) for as long as the object needs to be observed.
-
-Observers registered via `addObserver(_:)` are not retained. `ObjectMonitor` only keeps a `weak` reference to all observers, thus keeping itself free from retain-cycles.
-*/
+ The `ObjectMonitor` monitors changes to a single `NSManagedObject` instance. Observers that implement the `ObjectObserver` protocol may then register themselves to the `ObjectMonitor`'s `addObserver(_:)` method:
+ ```
+ let monitor = CoreStore.monitorObject(object)
+ monitor.addObserver(self)
+ ```
+ The created `ObjectMonitor` instance needs to be held on (retained) for as long as the object needs to be observed.
+ 
+ Observers registered via `addObserver(_:)` are not retained. `ObjectMonitor` only keeps a `weak` reference to all observers, thus keeping itself free from retain-cycles.
+ */
+@available(OSX, unavailable)
 public final class ObjectMonitor<T: NSManagedObject> {
     
-    // MARK: Public
-    
     /**
-    Returns the `NSManagedObject` instance being observed, or `nil` if the object was already deleted.
-    */
+     Returns the `NSManagedObject` instance being observed, or `nil` if the object was already deleted.
+     */
     public var object: T? {
         
         return self.fetchedResultsController.fetchedObjects?.first as? T
     }
     
     /**
-    Returns `true` if the `NSManagedObject` instance being observed still exists, or `false` if the object was already deleted.
-    */
+     Returns `true` if the `NSManagedObject` instance being observed still exists, or `false` if the object was already deleted.
+     */
     public var isObjectDeleted: Bool {
         
         return self.object?.managedObjectContext == nil
     }
     
     /**
-    Registers an `ObjectObserver` to be notified when changes to the receiver's `object` are made.
-    
-    To prevent retain-cycles, `ObjectMonitor` only keeps `weak` references to its observers.
-    
-    For thread safety, this method needs to be called from the main thread. An assertion failure will occur (on debug builds only) if called from any thread other than the main thread.
-    
-    Calling `addObserver(_:)` multiple times on the same observer is safe, as `ObjectMonitor` unregisters previous notifications to the observer before re-registering them.
-    
-    - parameter observer: an `ObjectObserver` to send change notifications to
-    */
-    public func addObserver<U: ObjectObserver where U.EntityType == T>(observer: U) {
+     Registers an `ObjectObserver` to be notified when changes to the receiver's `object` are made.
+     
+     To prevent retain-cycles, `ObjectMonitor` only keeps `weak` references to its observers.
+     
+     For thread safety, this method needs to be called from the main thread. An assertion failure will occur (on debug builds only) if called from any thread other than the main thread.
+     
+     Calling `addObserver(_:)` multiple times on the same observer is safe, as `ObjectMonitor` unregisters previous notifications to the observer before re-registering them.
+     
+     - parameter observer: an `ObjectObserver` to send change notifications to
+     */
+    public func addObserver<U: ObjectObserver where U.ObjectEntityType == T>(observer: U) {
         
         CoreStore.assert(
             NSThread.isMainThread(),
@@ -95,68 +82,72 @@ public final class ObjectMonitor<T: NSManagedObject> {
         self.removeObserver(observer)
         
         self.registerChangeNotification(
-            &NotificationKey.willChangeObject,
+            &self.willChangeObjectKey,
             name: ObjectMonitorWillChangeObjectNotification,
             toObserver: observer,
             callback: { [weak observer] (monitor) -> Void in
                 
-                if let object = monitor.object, let observer = observer {
+                guard let object = monitor.object, let observer = observer else {
                     
-                    observer.objectMonitor(monitor, willUpdateObject: object)
+                    return
                 }
+                observer.objectMonitor(monitor, willUpdateObject: object)
             }
         )
         self.registerObjectNotification(
-            &NotificationKey.didDeleteObject,
+            &self.didDeleteObjectKey,
             name: ObjectMonitorDidDeleteObjectNotification,
             toObserver: observer,
             callback: { [weak observer] (monitor, object) -> Void in
                 
-                if let observer = observer {
+                guard let observer = observer else {
                     
-                    observer.objectMonitor(monitor, didDeleteObject: object)
+                    return
                 }
+                observer.objectMonitor(monitor, didDeleteObject: object)
             }
         )
         self.registerObjectNotification(
-            &NotificationKey.didUpdateObject,
+            &self.didUpdateObjectKey,
             name: ObjectMonitorDidUpdateObjectNotification,
             toObserver: observer,
             callback: { [weak self, weak observer] (monitor, object) -> Void in
                 
-                if let strongSelf = self, let observer = observer {
+                guard let strongSelf = self, let observer = observer else {
                     
-                    let previousCommitedAttributes = strongSelf.lastCommittedAttributes
-                    let currentCommitedAttributes = object.committedValuesForKeys(nil) as! [String: NSObject]
-                    
-                    let changedKeys = currentCommitedAttributes.keys.reduce(Set<String>()) { (var changedKeys, key) -> Set<String> in
-                        
-                        if previousCommitedAttributes[key] != currentCommitedAttributes[key] {
-                            
-                            changedKeys.insert(key)
-                        }
-                        return changedKeys
-                    }
-                    
-                    strongSelf.lastCommittedAttributes = currentCommitedAttributes
-                    observer.objectMonitor(
-                        monitor,
-                        didUpdateObject: object,
-                        changedPersistentKeys: changedKeys
-                    )
+                    return
                 }
+                
+                let previousCommitedAttributes = strongSelf.lastCommittedAttributes
+                let currentCommitedAttributes = object.committedValuesForKeys(nil) as! [String: NSObject]
+                
+                var changedKeys = Set<String>()
+                for key in currentCommitedAttributes.keys {
+                    
+                    if previousCommitedAttributes[key] != currentCommitedAttributes[key] {
+                        
+                        changedKeys.insert(key)
+                    }
+                }
+                
+                strongSelf.lastCommittedAttributes = currentCommitedAttributes
+                observer.objectMonitor(
+                    monitor,
+                    didUpdateObject: object,
+                    changedPersistentKeys: changedKeys
+                )
             }
         )
     }
     
     /**
-    Unregisters an `ObjectObserver` from receiving notifications for changes to the receiver's `object`.
-    
-    For thread safety, this method needs to be called from the main thread. An assertion failure will occur (on debug builds only) if called from any thread other than the main thread.
-    
-    - parameter observer: an `ObjectObserver` to unregister notifications to
-    */
-    public func removeObserver<U: ObjectObserver where U.EntityType == T>(observer: U) {
+     Unregisters an `ObjectObserver` from receiving notifications for changes to the receiver's `object`.
+     
+     For thread safety, this method needs to be called from the main thread. An assertion failure will occur (on debug builds only) if called from any thread other than the main thread.
+     
+     - parameter observer: an `ObjectObserver` to unregister notifications to
+     */
+    public func removeObserver<U: ObjectObserver where U.ObjectEntityType == T>(observer: U) {
         
         CoreStore.assert(
             NSThread.isMainThread(),
@@ -164,57 +155,67 @@ public final class ObjectMonitor<T: NSManagedObject> {
         )
         
         let nilValue: AnyObject? = nil
-        setAssociatedRetainedObject(nilValue, forKey: &NotificationKey.willChangeObject, inObject: observer)
-        setAssociatedRetainedObject(nilValue, forKey: &NotificationKey.didDeleteObject, inObject: observer)
-        setAssociatedRetainedObject(nilValue, forKey: &NotificationKey.didUpdateObject, inObject: observer)
+        setAssociatedRetainedObject(nilValue, forKey: &self.willChangeObjectKey, inObject: observer)
+        setAssociatedRetainedObject(nilValue, forKey: &self.didDeleteObjectKey, inObject: observer)
+        setAssociatedRetainedObject(nilValue, forKey: &self.didUpdateObjectKey, inObject: observer)
     }
     
     
     // MARK: Internal
     
-    internal init(dataStack: DataStack, object: T) {
+    internal convenience init(dataStack: DataStack, object: T) {
         
-        let context = dataStack.mainContext
+        self.init(context: dataStack.mainContext, object: object)
+    }
+    
+    internal convenience init(unsafeTransaction: UnsafeDataTransaction, object: T) {
         
-        let fetchRequest = NSFetchRequest()
+        self.init(context: unsafeTransaction.context, object: object)
+    }
+    
+    private init(context: NSManagedObjectContext, object: T) {
+        
+        let fetchRequest = CoreStoreFetchRequest()
         fetchRequest.entity = object.entity
-        
-        fetchRequest.fetchLimit = 1
+        fetchRequest.fetchLimit = 0
         fetchRequest.resultType = .ManagedObjectResultType
         fetchRequest.sortDescriptors = []
+        fetchRequest.includesPendingChanges = false
+        fetchRequest.shouldRefreshRefetchedObjects = true
         
-        let originalObjectID = object.objectID
-        Where("SELF", isEqualTo: originalObjectID).applyToFetchRequest(fetchRequest)
-        
-        let fetchedResultsController = NSFetchedResultsController(
+        let fetchedResultsController = CoreStoreFetchedResultsController<T>(
+            context: context,
             fetchRequest: fetchRequest,
-            managedObjectContext: context,
-            sectionNameKeyPath: nil,
-            cacheName: nil
+            fetchClauses: [Where("SELF", isEqualTo: object.objectID)]
         )
         
         let fetchedResultsControllerDelegate = FetchedResultsControllerDelegate()
         
-        self.originalObjectID = originalObjectID
         self.fetchedResultsController = fetchedResultsController
         self.fetchedResultsControllerDelegate = fetchedResultsControllerDelegate
-        self.parentStack = dataStack
         
         fetchedResultsControllerDelegate.handler = self
         fetchedResultsControllerDelegate.fetchedResultsController = fetchedResultsController
-        try! fetchedResultsController.performFetch()
+        try! fetchedResultsController.performFetchFromSpecifiedStores()
         
         self.lastCommittedAttributes = (self.object?.committedValuesForKeys(nil) as? [String: NSObject]) ?? [:]
     }
     
+    deinit {
+        
+        self.fetchedResultsControllerDelegate.fetchedResultsController = nil
+    }
+    
     
     // MARK: Private
     
-    private let originalObjectID: NSManagedObjectID
-    private let fetchedResultsController: NSFetchedResultsController
+    private let fetchedResultsController: CoreStoreFetchedResultsController<T>
     private let fetchedResultsControllerDelegate: FetchedResultsControllerDelegate
     private var lastCommittedAttributes = [String: NSObject]()
-    private weak var parentStack: DataStack?
+    
+    private var willChangeObjectKey: Void?
+    private var didDeleteObjectKey: Void?
+    private var didUpdateObjectKey: Void?
     
     private func registerChangeNotification(notificationKey: UnsafePointer<Void>, name: String, toObserver observer: AnyObject, callback: (monitor: ObjectMonitor<T>) -> Void) {
         
@@ -224,10 +225,11 @@ public final class ObjectMonitor<T: NSManagedObject> {
                 object: self,
                 closure: { [weak self] (note) -> Void in
                     
-                    if let strongSelf = self {
+                    guard let strongSelf = self else {
                         
-                        callback(monitor: strongSelf)
+                        return
                     }
+                    callback(monitor: strongSelf)
                 }
             ),
             forKey: notificationKey,
@@ -243,15 +245,13 @@ public final class ObjectMonitor<T: NSManagedObject> {
                 object: self,
                 closure: { [weak self] (note) -> Void in
                     
-                    if let strongSelf = self,
+                    guard let strongSelf = self,
                         let userInfo = note.userInfo,
-                        let object = userInfo[UserInfoKeyObject] as? T {
+                        let object = userInfo[UserInfoKeyObject] as? T else {
                             
-                            callback(
-                                monitor: strongSelf,
-                                object: object
-                            )
+                            return
                     }
+                    callback(monitor: strongSelf, object: object)
                 }
             ),
             forKey: notificationKey,
@@ -261,13 +261,36 @@ public final class ObjectMonitor<T: NSManagedObject> {
 }
 
 
+// MARK: - ObjectMonitor: Equatable
+
+@available(OSX, unavailable)
+public func ==<T: NSManagedObject>(lhs: ObjectMonitor<T>, rhs: ObjectMonitor<T>) -> Bool {
+    
+    return lhs === rhs
+}
+
+@available(OSX, unavailable)
+extension ObjectMonitor: Equatable { }
+
+
 // MARK: - ObjectMonitor: FetchedResultsControllerHandler
 
+@available(OSX, unavailable)
 extension ObjectMonitor: FetchedResultsControllerHandler {
     
     // MARK: FetchedResultsControllerHandler
     
-    private func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
+    internal func controllerWillChangeContent(controller: NSFetchedResultsController) {
+        
+        NSNotificationCenter.defaultCenter().postNotificationName(
+            ObjectMonitorWillChangeObjectNotification,
+            object: self
+        )
+    }
+    
+    internal func controllerDidChangeContent(controller: NSFetchedResultsController) { }
+    
+    internal func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
         
         switch type {
             
@@ -290,57 +313,18 @@ extension ObjectMonitor: FetchedResultsControllerHandler {
         }
     }
     
-    private func controllerWillChangeContent(controller: NSFetchedResultsController) {
+    internal func controller(controller: NSFetchedResultsController, didChangeSection sectionInfo: NSFetchedResultsSectionInfo, atIndex sectionIndex: Int, forChangeType type: NSFetchedResultsChangeType) { }
+    
+    internal func controller(controller: NSFetchedResultsController, sectionIndexTitleForSectionName sectionName: String?) -> String? {
         
-        NSNotificationCenter.defaultCenter().postNotificationName(
-            ObjectMonitorWillChangeObjectNotification,
-            object: self
-        )
+        return sectionName
     }
 }
 
 
-// MARK: - FetchedResultsControllerHandler
+private let ObjectMonitorWillChangeObjectNotification = "ObjectMonitorWillChangeObjectNotification"
+private let ObjectMonitorDidDeleteObjectNotification = "ObjectMonitorDidDeleteObjectNotification"
+private let ObjectMonitorDidUpdateObjectNotification = "ObjectMonitorDidUpdateObjectNotification"
 
-private protocol FetchedResultsControllerHandler: class {
-    
-    func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?)
-    
-    func controllerWillChangeContent(controller: NSFetchedResultsController)
-}
+private let UserInfoKeyObject = "UserInfoKeyObject"
 
-
-// MARK: - FetchedResultsControllerDelegate
-
-private final class FetchedResultsControllerDelegate: NSObject, NSFetchedResultsControllerDelegate {
-    
-    // MARK: NSFetchedResultsControllerDelegate
-    
-    @objc dynamic func controllerWillChangeContent(controller: NSFetchedResultsController) {
-        
-        self.handler?.controllerWillChangeContent(controller)
-    }
-    
-    @objc dynamic func controller(controller: NSFetchedResultsController, didChangeObject anObject: NSManagedObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
-        
-        self.handler?.controller(controller, didChangeObject: anObject, atIndexPath: indexPath, forChangeType: type, newIndexPath: newIndexPath)
-    }
-    
-    
-    // MARK: Private
-    
-    weak var handler: FetchedResultsControllerHandler?
-    weak var fetchedResultsController: NSFetchedResultsController? {
-        
-        didSet {
-            
-            oldValue?.delegate = nil
-            self.fetchedResultsController?.delegate = self
-        }
-    }
-    
-    deinit {
-        
-        self.fetchedResultsController?.delegate = nil
-    }
-}

CoreStore/Observing/ObjectObserver.swift

@@ -2,7 +2,7 @@
 //  ObjectObserver.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -30,40 +30,64 @@ import CoreData
 // MARK: - ObjectObserver
 
 /**
-Implement the `ObjectObserver` protocol to observe changes to a single `NSManagedObject` instance. `ObjectObserver`s may register themselves to a `ObjectMonitor`'s `addObserver(_:)` method:
-
-    let monitor = CoreStore.monitorObject(object)
-    monitor.addObserver(self)
-*/
+ Implement the `ObjectObserver` protocol to observe changes to a single `NSManagedObject` instance. `ObjectObserver`s may register themselves to a `ObjectMonitor`'s `addObserver(_:)` method:
+ ```
+ let monitor = CoreStore.monitorObject(object)
+ monitor.addObserver(self)
+ ```
+ */
+@available(OSX, unavailable)
 public protocol ObjectObserver: class {
     
     /**
-    The `NSManagedObject` type for the observed object
-    */
-    typealias EntityType: NSManagedObject
+     The `NSManagedObject` type for the observed object
+     */
+    associatedtype ObjectEntityType: NSManagedObject
     
     /**
-    Handles processing just before a change to the observed `object` occurs
-    
-    - parameter monitor: the `ObjectMonitor` monitoring the object being observed
-    - parameter object: the `NSManagedObject` instance being observed
-    */
-    func objectMonitor(monitor: ObjectMonitor<EntityType>, willUpdateObject object: EntityType)
+     Handles processing just before a change to the observed `object` occurs
+     
+     - parameter monitor: the `ObjectMonitor` monitoring the object being observed
+     - parameter object: the `NSManagedObject` instance being observed
+     */
+    func objectMonitor(monitor: ObjectMonitor<ObjectEntityType>, willUpdateObject object: ObjectEntityType)
     
     /**
-    Handles processing right after a change to the observed `object` occurs
-    
-    - parameter monitor: the `ObjectMonitor` monitoring the object being observed
-    - parameter object: the `NSManagedObject` instance being observed
-    - parameter changedPersistentKeys: a `Set` of key paths for the attributes that were changed. Note that `changedPersistentKeys` only contains keys for attributes/relationships present in the persistent store, thus transient properties will not be reported.
-    */
-    func objectMonitor(monitor: ObjectMonitor<EntityType>, didUpdateObject object: EntityType, changedPersistentKeys: Set<KeyPath>)
+     Handles processing right after a change to the observed `object` occurs
+     
+     - parameter monitor: the `ObjectMonitor` monitoring the object being observed
+     - parameter object: the `NSManagedObject` instance being observed
+     - parameter changedPersistentKeys: a `Set` of key paths for the attributes that were changed. Note that `changedPersistentKeys` only contains keys for attributes/relationships present in the persistent store, thus transient properties will not be reported.
+     */
+    func objectMonitor(monitor: ObjectMonitor<ObjectEntityType>, didUpdateObject object: ObjectEntityType, changedPersistentKeys: Set<KeyPath>)
     
     /**
-    Handles processing right after `object` is deleted
-    
-    - parameter monitor: the `ObjectMonitor` monitoring the object being observed
-    - parameter object: the `NSManagedObject` instance being observed
-    */
-    func objectMonitor(monitor: ObjectMonitor<EntityType>, didDeleteObject object: EntityType)
+     Handles processing right after `object` is deleted
+     
+     - parameter monitor: the `ObjectMonitor` monitoring the object being observed
+     - parameter object: the `NSManagedObject` instance being observed
+     */
+    func objectMonitor(monitor: ObjectMonitor<ObjectEntityType>, didDeleteObject object: ObjectEntityType)
+}
+
+
+// MARK: - ObjectObserver (Default Implementations)
+
+@available(OSX, unavailable)
+public extension ObjectObserver {
+    
+    /**
+     The default implementation does nothing.
+     */
+    func objectMonitor(monitor: ObjectMonitor<ObjectEntityType>, willUpdateObject object: ObjectEntityType) { }
+    
+    /**
+     The default implementation does nothing.
+     */
+    func objectMonitor(monitor: ObjectMonitor<ObjectEntityType>, didUpdateObject object: ObjectEntityType, changedPersistentKeys: Set<KeyPath>) { }
+    
+    /**
+     The default implementation does nothing.
+     */
+    func objectMonitor(monitor: ObjectMonitor<ObjectEntityType>, didDeleteObject object: ObjectEntityType) { }
 }

CoreStore/Observing/SectionBy.swift

@@ -2,7 +2,7 @@
 //  SectionBy.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -30,34 +30,34 @@ import CoreData
 // MARK: - SectionBy
 
 /**
-The `SectionBy` clause indicates the key path to use to group the `ListMonitor` objects into sections. An optional closure can also be provided to transform the value into an appropriate section name:
-
-    let monitor = CoreStore.monitorSectionedList(
-        From(MyPersonEntity),
-        SectionBy("age") { "Age \($0)" },
-        OrderBy(.Ascending("lastName"))
-    )
-*/
+ The `SectionBy` clause indicates the key path to use to group the `ListMonitor` objects into sections. An optional closure can also be provided to transform the value into an appropriate section name:
+ ```
+ let monitor = CoreStore.monitorSectionedList(
+     From(MyPersonEntity),
+     SectionBy("age") { "Age \($0)" },
+     OrderBy(.Ascending("lastName"))
+ )
+ ```
+ */
+@available(OSX, unavailable)
 public struct SectionBy {
     
-    // MARK: Public
-    
     /**
-    Initializes a `SectionBy` clause with the key path to use to group `ListMonitor` objects into sections
-    
-    - parameter sectionKeyPath: the key path to use to group the objects into sections
-    */
+     Initializes a `SectionBy` clause with the key path to use to group `ListMonitor` objects into sections
+     
+     - parameter sectionKeyPath: the key path to use to group the objects into sections
+     */
     public init(_ sectionKeyPath: KeyPath) {
         
         self.init(sectionKeyPath, { $0 })
     }
     
     /**
-    Initializes a `SectionBy` clause with the key path to use to group `ListMonitor` objects into sections, and a closure to transform the value for the key path to an appropriate section name
-    
-    - parameter sectionKeyPath: the key path to use to group the objects into sections
-    - parameter sectionIndexTransformer: a closure to transform the value for the key path to an appropriate section name
-    */
+     Initializes a `SectionBy` clause with the key path to use to group `ListMonitor` objects into sections, and a closure to transform the value for the key path to an appropriate section name
+     
+     - parameter sectionKeyPath: the key path to use to group the objects into sections
+     - parameter sectionIndexTransformer: a closure to transform the value for the key path to an appropriate section name
+     */
     public init(_ sectionKeyPath: KeyPath, _ sectionIndexTransformer: (sectionName: String?) -> String?) {
         
         self.sectionKeyPath = sectionKeyPath

CoreStore/Observing/UnsafeDataTransaction+Observing.swift

@@ -0,0 +1,198 @@
+//
+//  UnsafeDataTransaction+Observing.swift
+//  CoreStore
+//
+//  Copyright © 2016 John Rommel Estropia
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+//
+
+import Foundation
+import CoreData
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
+
+
+// MARK: - UnsafeDataTransaction
+
+@available(OSX, unavailable)
+public extension UnsafeDataTransaction {
+    
+    /**
+     Creates a `ObjectMonitor` for the specified `NSManagedObject`. Multiple `ObjectObserver`s may then register themselves to be notified when changes are made to the `NSManagedObject`.
+     
+     - parameter object: the `NSManagedObject` to observe changes from
+     - returns: a `ObjectMonitor` that monitors changes to `object`
+     */
+    @warn_unused_result
+    public func monitorObject<T: NSManagedObject>(object: T) -> ObjectMonitor<T> {
+        
+        return ObjectMonitor(
+            unsafeTransaction: self,
+            object: object
+        )
+    }
+    
+    /**
+     Creates a `ListMonitor` for a list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: a `ListMonitor` instance that monitors changes to the list
+     */
+    @warn_unused_result
+    public func monitorList<T: NSManagedObject>(from: From<T>, _ fetchClauses: FetchClause...) -> ListMonitor<T> {
+        
+        return self.monitorList(from, fetchClauses)
+    }
+    
+    /**
+     Creates a `ListMonitor` for a list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: a `ListMonitor` instance that monitors changes to the list
+     */
+    @warn_unused_result
+    public func monitorList<T: NSManagedObject>(from: From<T>, _ fetchClauses: [FetchClause]) -> ListMonitor<T> {
+        
+        CoreStore.assert(
+            fetchClauses.filter { $0 is OrderBy }.count > 0,
+            "A ListMonitor requires an OrderBy clause."
+        )
+        
+        return ListMonitor(
+            unsafeTransaction: self,
+            from: from,
+            sectionBy: nil,
+            fetchClauses: fetchClauses
+        )
+    }
+    
+    /**
+     Asynchronously creates a `ListMonitor` for a list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list. Since `NSFetchedResultsController` greedily locks the persistent store on initial fetch, you may prefer this method instead of the synchronous counterpart to avoid deadlocks while background updates/saves are being executed.
+     
+     - parameter createAsynchronously: the closure that receives the created `ListMonitor` instance
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     */
+    public func monitorList<T: NSManagedObject>(createAsynchronously createAsynchronously: (ListMonitor<T>) -> Void, _ from: From<T>, _ fetchClauses: FetchClause...) {
+        
+        self.monitorList(createAsynchronously: createAsynchronously, from, fetchClauses)
+    }
+    
+    /**
+     Asynchronously creates a `ListMonitor` for a list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list. Since `NSFetchedResultsController` greedily locks the persistent store on initial fetch, you may prefer this method instead of the synchronous counterpart to avoid deadlocks while background updates/saves are being executed.
+     
+     - parameter createAsynchronously: the closure that receives the created `ListMonitor` instance
+     - parameter from: a `From` clause indicating the entity type
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     */
+    public func monitorList<T: NSManagedObject>(createAsynchronously createAsynchronously: (ListMonitor<T>) -> Void, _ from: From<T>, _ fetchClauses: [FetchClause])  {
+        
+        CoreStore.assert(
+            fetchClauses.filter { $0 is OrderBy }.count > 0,
+            "A ListMonitor requires an OrderBy clause."
+        )
+        
+        _ = ListMonitor(
+            unsafeTransaction: self,
+            from: from,
+            sectionBy: nil,
+            fetchClauses: fetchClauses,
+            createAsynchronously: createAsynchronously
+        )
+    }
+    
+    /**
+     Creates a `ListMonitor` for a sectioned list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections.
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: a `ListMonitor` instance that monitors changes to the list
+     */
+    @warn_unused_result
+    public func monitorSectionedList<T: NSManagedObject>(from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: FetchClause...) -> ListMonitor<T> {
+        
+        return self.monitorSectionedList(from, sectionBy, fetchClauses)
+    }
+    
+    /**
+     Creates a `ListMonitor` for a sectioned list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list.
+     
+     - parameter from: a `From` clause indicating the entity type
+     - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections.
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     - returns: a `ListMonitor` instance that monitors changes to the list
+     */
+    @warn_unused_result
+    public func monitorSectionedList<T: NSManagedObject>(from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: [FetchClause]) -> ListMonitor<T> {
+        
+        CoreStore.assert(
+            fetchClauses.filter { $0 is OrderBy }.count > 0,
+            "A ListMonitor requires an OrderBy clause."
+        )
+        
+        return ListMonitor(
+            unsafeTransaction: self,
+            from: from,
+            sectionBy: sectionBy,
+            fetchClauses: fetchClauses
+        )
+    }
+    
+    /**
+     Asynchronously creates a `ListMonitor` for a sectioned list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list. Since `NSFetchedResultsController` greedily locks the persistent store on initial fetch, you may prefer this method instead of the synchronous counterpart to avoid deadlocks while background updates/saves are being executed.
+     
+     - parameter createAsynchronously: the closure that receives the created `ListMonitor` instance
+     - parameter from: a `From` clause indicating the entity type
+     - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections.
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     */
+    public func monitorSectionedList<T: NSManagedObject>(createAsynchronously createAsynchronously: (ListMonitor<T>) -> Void, _ from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: FetchClause...) {
+        
+        self.monitorSectionedList(createAsynchronously: createAsynchronously, from, sectionBy, fetchClauses)
+    }
+    
+    /**
+     Asynchronously creates a `ListMonitor` for a sectioned list of `NSManagedObject`s that satisfy the specified fetch clauses. Multiple `ListObserver`s may then register themselves to be notified when changes are made to the list. Since `NSFetchedResultsController` greedily locks the persistent store on initial fetch, you may prefer this method instead of the synchronous counterpart to avoid deadlocks while background updates/saves are being executed.
+     
+     - parameter createAsynchronously: the closure that receives the created `ListMonitor` instance
+     - parameter from: a `From` clause indicating the entity type
+     - parameter sectionBy: a `SectionBy` clause indicating the keyPath for the attribute to use when sorting the list into sections.
+     - parameter fetchClauses: a series of `FetchClause` instances for fetching the object list. Accepts `Where`, `OrderBy`, and `Tweak` clauses.
+     */
+    public func monitorSectionedList<T: NSManagedObject>(createAsynchronously createAsynchronously: (ListMonitor<T>) -> Void, _ from: From<T>, _ sectionBy: SectionBy, _ fetchClauses: [FetchClause]) {
+        
+        CoreStore.assert(
+            fetchClauses.filter { $0 is OrderBy }.count > 0,
+            "A ListMonitor requires an OrderBy clause."
+        )
+        
+        _ = ListMonitor(
+            unsafeTransaction: self,
+            from: from,
+            sectionBy: sectionBy,
+            fetchClauses: fetchClauses,
+            createAsynchronously: createAsynchronously
+        )
+    }
+}

CoreStore/Saving and Processing/AsynchronousDataTransaction.swift

@@ -2,7 +2,7 @@
 //  AsynchronousDataTransaction.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -25,23 +25,23 @@
 
 import Foundation
 import CoreData
-import GCDKit
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
 
 
 // MARK: - AsynchronousDataTransaction
 
 /**
-The `AsynchronousDataTransaction` provides an interface for `NSManagedObject` creates, updates, and deletes. A transaction object should typically be only used from within a transaction block initiated from `DataStack.beginAsynchronous(_:)`, or from `CoreStore.beginAsynchronous(_:)`.
-*/
+ The `AsynchronousDataTransaction` provides an interface for `NSManagedObject` creates, updates, and deletes. A transaction object should typically be only used from within a transaction block initiated from `DataStack.beginAsynchronous(_:)`, or from `CoreStore.beginAsynchronous(_:)`.
+ */
 public final class AsynchronousDataTransaction: BaseDataTransaction {
     
-    // MARK: Public
-    
     /**
-    Saves the transaction changes. This method should not be used after the `commit()` method was already called once.
-    
-    - parameter completion: the block executed after the save completes. Success or failure is reported by the `SaveResult` argument of the block.
-    */
+     Saves the transaction changes. This method should not be used after the `commit()` method was already called once.
+     
+     - parameter completion: the block executed after the save completes. Success or failure is reported by the `SaveResult` argument of the block.
+     */
     public func commit(completion: (result: SaveResult) -> Void = { _ in }) {
         
         CoreStore.assert(
@@ -54,22 +54,23 @@ public final class AsynchronousDataTransaction: BaseDataTransaction {
         )
         
         self.isCommitted = true
-        let semaphore = GCDSemaphore(0)
+        let group = GCDGroup()
+        group.enter()
         self.context.saveAsynchronouslyWithCompletion { (result) -> Void in
             
             self.result = result
             completion(result: result)
-            semaphore.signal()
+            group.leave()
         }
-        semaphore.wait()
+        group.wait()
     }
     
     /**
-    Begins a child transaction synchronously where NSManagedObject creates, updates, and deletes can be made. This method should not be used after the `commit()` method was already called once.
-    
-    - parameter closure: the block where creates, updates, and deletes can be made to the transaction. Transaction blocks are executed serially in a background queue, and all changes are made from a concurrent `NSManagedObjectContext`.
-    - returns: a `SaveResult` value indicating success or failure, or `nil` if the transaction was not comitted synchronously
-    */
+     Begins a child transaction synchronously where NSManagedObject creates, updates, and deletes can be made. This method should not be used after the `commit()` method was already called once.
+     
+     - parameter closure: the block where creates, updates, and deletes can be made to the transaction. Transaction blocks are executed serially in a background queue, and all changes are made from a concurrent `NSManagedObjectContext`.
+     - returns: a `SaveResult` value indicating success or failure, or `nil` if the transaction was not comitted synchronously
+     */
     public func beginSynchronous(closure: (transaction: SynchronousDataTransaction) -> Void) -> SaveResult? {
         
         CoreStore.assert(
@@ -91,11 +92,11 @@ public final class AsynchronousDataTransaction: BaseDataTransaction {
     // MARK: BaseDataTransaction
     
     /**
-    Creates a new `NSManagedObject` with the specified entity type.
-    
-    - parameter into: the `Into` clause indicating the destination `NSManagedObject` entity type and the destination configuration
-    - returns: a new `NSManagedObject` instance of the specified entity type.
-    */
+     Creates a new `NSManagedObject` with the specified entity type.
+     
+     - parameter into: the `Into` clause indicating the destination `NSManagedObject` entity type and the destination configuration
+     - returns: a new `NSManagedObject` instance of the specified entity type.
+     */
     public override func create<T: NSManagedObject>(into: Into<T>) -> T {
         
         CoreStore.assert(
@@ -107,11 +108,12 @@ public final class AsynchronousDataTransaction: BaseDataTransaction {
     }
     
     /**
-    Returns an editable proxy of a specified `NSManagedObject`. This method should not be used after the `commit()` method was already called once.
-    
-    - parameter object: the `NSManagedObject` type to be edited
-    - returns: an editable proxy for the specified `NSManagedObject`.
-    */
+     Returns an editable proxy of a specified `NSManagedObject`. This method should not be used after the `commit()` method was already called once.
+     
+     - parameter object: the `NSManagedObject` type to be edited
+     - returns: an editable proxy for the specified `NSManagedObject`.
+     */
+    @warn_unused_result
     public override func edit<T: NSManagedObject>(object: T?) -> T? {
         
         CoreStore.assert(
@@ -123,12 +125,13 @@ public final class AsynchronousDataTransaction: BaseDataTransaction {
     }
     
     /**
-    Returns an editable proxy of the object with the specified `NSManagedObjectID`. This method should not be used after the `commit()` method was already called once.
-    
-    - parameter into: an `Into` clause specifying the entity type
-    - parameter objectID: the `NSManagedObjectID` for the object to be edited
-    - returns: an editable proxy for the specified `NSManagedObject`.
-    */
+     Returns an editable proxy of the object with the specified `NSManagedObjectID`. This method should not be used after the `commit()` method was already called once.
+     
+     - parameter into: an `Into` clause specifying the entity type
+     - parameter objectID: the `NSManagedObjectID` for the object to be edited
+     - returns: an editable proxy for the specified `NSManagedObject`.
+     */
+    @warn_unused_result
     public override func edit<T: NSManagedObject>(into: Into<T>, _ objectID: NSManagedObjectID) -> T? {
         
         CoreStore.assert(
@@ -140,10 +143,10 @@ public final class AsynchronousDataTransaction: BaseDataTransaction {
     }
     
     /**
-    Deletes a specified `NSManagedObject`. This method should not be used after the `commit()` method was already called once.
-    
-    - parameter object: the `NSManagedObject` type to be deleted
-    */
+     Deletes a specified `NSManagedObject`. This method should not be used after the `commit()` method was already called once.
+     
+     - parameter object: the `NSManagedObject` type to be deleted
+     */
     public override func delete(object: NSManagedObject?) {
         
         CoreStore.assert(
@@ -155,12 +158,12 @@ public final class AsynchronousDataTransaction: BaseDataTransaction {
     }
     
     /**
-    Deletes the specified `NSManagedObject`s.
-    
-    - parameter object1: the `NSManagedObject` type to be deleted
-    - parameter object2: another `NSManagedObject` type to be deleted
-    - parameter objects: other `NSManagedObject`s type to be deleted
-    */
+     Deletes the specified `NSManagedObject`s.
+     
+     - parameter object1: the `NSManagedObject` type to be deleted
+     - parameter object2: another `NSManagedObject` type to be deleted
+     - parameter objects: other `NSManagedObject`s type to be deleted
+     */
     public override func delete(object1: NSManagedObject?, _ object2: NSManagedObject?, _ objects: NSManagedObject?...) {
         
         CoreStore.assert(
@@ -168,15 +171,15 @@ public final class AsynchronousDataTransaction: BaseDataTransaction {
             "Attempted to delete an entities from an already committed \(typeName(self))."
         )
         
-        super.delete([object1, object2] + objects)
+        super.delete(([object1, object2] + objects).flatMap { $0 })
     }
     
     /**
-    Deletes the specified `NSManagedObject`s.
-    
-    - parameter objects: the `NSManagedObject`s type to be deleted
-    */
-    public override func delete(objects: [NSManagedObject?]) {
+     Deletes the specified `NSManagedObject`s.
+     
+     - parameter objects: the `NSManagedObject`s type to be deleted
+     */
+    public override func delete<S: SequenceType where S.Generator.Element: NSManagedObject>(objects: S) {
         
         CoreStore.assert(
             !self.isCommitted,
@@ -187,16 +190,21 @@ public final class AsynchronousDataTransaction: BaseDataTransaction {
     }
     
     /**
-    Rolls back the transaction by resetting the `NSManagedObjectContext`. After calling this method, all `NSManagedObjects` fetched within the transaction will become invalid. This method should not be used after the `commit()` method was already called once.
-    */
-    public override func rollback() {
+     Rolls back the transaction by resetting the `NSManagedObjectContext`. After calling this method, all `NSManagedObjects` fetched within the transaction will become invalid. This method should not be used after the `commit()` method was already called once.
+     */
+    @available(*, deprecated=1.3.4, message="Resetting the context is inherently unsafe. This method will be removed in the near future. Use `beginUnsafe()` to create transactions with `undo` support.")
+    public func rollback() {
         
         CoreStore.assert(
             !self.isCommitted,
             "Attempted to rollback an already committed \(typeName(self))."
         )
+        CoreStore.assert(
+            self.transactionQueue.isCurrentExecutionContext(),
+            "Attempted to rollback a \(typeName(self)) outside its designated queue."
+        )
         
-        super.rollback()
+        self.context.reset()
     }
     
     
@@ -206,7 +214,7 @@ public final class AsynchronousDataTransaction: BaseDataTransaction {
         
         self.closure = closure
         
-        super.init(mainContext: mainContext, queue: queue)
+        super.init(mainContext: mainContext, queue: queue, supportsUndo: false, bypassesQueueing: false)
     }
     
     internal func perform() {

CoreStore/Saving and Processing/BaseDataTransaction.swift

@@ -2,7 +2,7 @@
 //  BaseDataTransaction.swift
 //  CoreStore
 //
-//  Copyright (c) 2014 John Rommel Estropia
+//  Copyright © 2014 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -25,36 +25,38 @@
 
 import Foundation
 import CoreData
-import GCDKit
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
 
 
 // MARK: - BaseDataTransaction
 
 /**
-The `BaseDataTransaction` is an abstract interface for `NSManagedObject` creates, updates, and deletes. All `BaseDataTransaction` subclasses manage a private `NSManagedObjectContext` which are direct children of the `NSPersistentStoreCoordinator`'s root `NSManagedObjectContext`. This means that all updates are saved first to the persistent store, and then propagated up to the read-only `NSManagedObjectContext`.
-*/
+ The `BaseDataTransaction` is an abstract interface for `NSManagedObject` creates, updates, and deletes. All `BaseDataTransaction` subclasses manage a private `NSManagedObjectContext` which are direct children of the `NSPersistentStoreCoordinator`'s root `NSManagedObjectContext`. This means that all updates are saved first to the persistent store, and then propagated up to the read-only `NSManagedObjectContext`.
+ */
 public /*abstract*/ class BaseDataTransaction {
     
     // MARK: Object management
     
     /**
-    Indicates if the transaction has pending changes
-    */
+     Indicates if the transaction has pending changes
+     */
     public var hasChanges: Bool {
         
         return self.context.hasChanges
     }
     
     /**
-    Creates a new `NSManagedObject` with the specified entity type.
-    
-    - parameter into: the `Into` clause indicating the destination `NSManagedObject` entity type and the destination configuration
-    - returns: a new `NSManagedObject` instance of the specified entity type.
-    */
+     Creates a new `NSManagedObject` with the specified entity type.
+     
+     - parameter into: the `Into` clause indicating the destination `NSManagedObject` entity type and the destination configuration
+     - returns: a new `NSManagedObject` instance of the specified entity type.
+     */
     public func create<T: NSManagedObject>(into: Into<T>) -> T {
         
         CoreStore.assert(
-            self.bypassesQueueing || self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to create an entity of type \(typeName(T)) outside its designated queue."
         )
         
@@ -99,32 +101,37 @@ public /*abstract*/ class BaseDataTransaction {
     }
     
     /**
-    Returns an editable proxy of a specified `NSManagedObject`.
-    
-    - parameter object: the `NSManagedObject` type to be edited
-    - returns: an editable proxy for the specified `NSManagedObject`.
-    */
+     Returns an editable proxy of a specified `NSManagedObject`.
+     
+     - parameter object: the `NSManagedObject` type to be edited
+     - returns: an editable proxy for the specified `NSManagedObject`.
+     */
+    @warn_unused_result
     public func edit<T: NSManagedObject>(object: T?) -> T? {
         
         CoreStore.assert(
-            self.bypassesQueueing || self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to update an entity of type \(typeName(object)) outside its designated queue."
         )
-        
-        return object?.inContext(self.context)
+        guard let object = object else {
+            
+            return nil
+        }
+        return self.context.fetchExisting(object)
     }
     
     /**
-    Returns an editable proxy of the object with the specified `NSManagedObjectID`. 
-    
-    - parameter into: an `Into` clause specifying the entity type
-    - parameter objectID: the `NSManagedObjectID` for the object to be edited
-    - returns: an editable proxy for the specified `NSManagedObject`.
-    */
+     Returns an editable proxy of the object with the specified `NSManagedObjectID`.
+     
+     - parameter into: an `Into` clause specifying the entity type
+     - parameter objectID: the `NSManagedObjectID` for the object to be edited
+     - returns: an editable proxy for the specified `NSManagedObject`.
+     */
+    @warn_unused_result
     public func edit<T: NSManagedObject>(into: Into<T>, _ objectID: NSManagedObjectID) -> T? {
         
         CoreStore.assert(
-            self.bypassesQueueing || self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to update an entity of type \(typeName(T)) outside its designated queue."
         )
         CoreStore.assert(
@@ -132,69 +139,304 @@ public /*abstract*/ class BaseDataTransaction {
                 || (into.configuration ?? Into.defaultConfigurationName) == objectID.persistentStore?.configurationName,
             "Attempted to update an entity of type \(typeName(T)) but the specified persistent store do not match the `NSManagedObjectID`."
         )
-        
-        return (into.entityClass as! NSManagedObject.Type).inContext(self.context, withObjectID: objectID) as? T
+        return self.fetchExisting(objectID) as? T
     }
     
     /**
-    Deletes a specified `NSManagedObject`.
-    
-    - parameter object: the `NSManagedObject` to be deleted
-    */
+     Deletes a specified `NSManagedObject`.
+     
+     - parameter object: the `NSManagedObject` to be deleted
+     */
     public func delete(object: NSManagedObject?) {
         
         CoreStore.assert(
-            self.bypassesQueueing || self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to delete an entity outside its designated queue."
         )
-        
-        object?.inContext(self.context)?.deleteFromContext()
+        guard let object = object else {
+            
+            return
+        }
+        self.context.fetchExisting(object)?.deleteFromContext()
     }
     
     /**
-    Deletes the specified `NSManagedObject`s.
-    
-    - parameter object1: the `NSManagedObject` to be deleted
-    - parameter object2: another `NSManagedObject` to be deleted
-    - parameter objects: other `NSManagedObject`s to be deleted
-    */
+     Deletes the specified `NSManagedObject`s.
+     
+     - parameter object1: the `NSManagedObject` to be deleted
+     - parameter object2: another `NSManagedObject` to be deleted
+     - parameter objects: other `NSManagedObject`s to be deleted
+     */
     public func delete(object1: NSManagedObject?, _ object2: NSManagedObject?, _ objects: NSManagedObject?...) {
         
-        self.delete([object1, object2] + objects)
+        self.delete(([object1, object2] + objects).flatMap { $0 })
     }
     
     /**
-    Deletes the specified `NSManagedObject`s.
-    
-    - parameter objects: the `NSManagedObject`s to be deleted
-    */
-    public func delete(objects: [NSManagedObject?]) {
+     Deletes the specified `NSManagedObject`s.
+     
+     - parameter objects: the `NSManagedObject`s to be deleted
+     */
+    public func delete<S: SequenceType where S.Generator.Element: NSManagedObject>(objects: S) {
         
         CoreStore.assert(
-            self.bypassesQueueing || self.transactionQueue.isCurrentExecutionContext(),
+            self.isRunningInAllowedQueue(),
             "Attempted to delete entities outside their designated queue."
         )
         
         let context = self.context
-        for object in objects {
-            
-            object?.inContext(context)?.deleteFromContext()
-        }
+        objects.forEach { context.fetchExisting($0)?.deleteFromContext() }
     }
     
-    // MARK: Saving changes
-    
     /**
-    Rolls back the transaction by resetting the `NSManagedObjectContext`. After calling this method, all `NSManagedObjects` fetched within the transaction will become invalid.
-    */
-    public func rollback() {
+     Refreshes all registered objects `NSManagedObject`s in the transaction.
+     */
+    public func refreshAndMergeAllObjects() {
         
         CoreStore.assert(
-            self.bypassesQueueing || self.transactionQueue.isCurrentExecutionContext(),
-            "Attempted to rollback a \(typeName(self)) outside its designated queue."
+            self.isRunningInAllowedQueue(),
+            "Attempted to refresh entities outside their designated queue."
         )
         
-        self.context.reset()
+        self.context.refreshAndMergeAllObjects()
+    }
+    
+    
+    // MARK: Inspecting Pending Objects
+    
+    /**
+    Returns all pending `NSManagedObject`s that were inserted to the transaction. This method should not be called after the `commit()` method was called.
+    
+    - returns: a `Set` of pending `NSManagedObject`s that were inserted to the transaction.
+    */
+    public func insertedObjects() -> Set<NSManagedObject> {
+        
+        CoreStore.assert(
+            self.transactionQueue.isCurrentExecutionContext(),
+            "Attempted to access inserted objects from a \(typeName(self)) outside its designated queue."
+        )
+        CoreStore.assert(
+            !self.isCommitted,
+            "Attempted to access inserted objects from an already committed \(typeName(self))."
+        )
+        
+        return self.context.insertedObjects
+    }
+    
+    /**
+     Returns all pending `NSManagedObject`s of the specified type that were inserted to the transaction. This method should not be called after the `commit()` method was called.
+     
+     - parameter entity: the `NSManagedObject` subclass to filter
+     - returns: a `Set` of pending `NSManagedObject`s of the specified type that were inserted to the transaction.
+     */
+    public func insertedObjects<T: NSManagedObject>(entity: T.Type) -> Set<T> {
+        
+        CoreStore.assert(
+            self.transactionQueue.isCurrentExecutionContext(),
+            "Attempted to access inserted objects from a \(typeName(self)) outside its designated queue."
+        )
+        CoreStore.assert(
+            !self.isCommitted,
+            "Attempted to access inserted objects from an already committed \(typeName(self))."
+        )
+        
+        return Set(self.context.insertedObjects.flatMap { $0 as? T })
+    }
+    
+    /**
+     Returns all pending `NSManagedObjectID`s that were inserted to the transaction. This method should not be called after the `commit()` method was called.
+     
+     - returns: a `Set` of pending `NSManagedObjectID`s that were inserted to the transaction.
+     */
+    public func insertedObjectIDs() -> Set<NSManagedObjectID> {
+        
+        CoreStore.assert(
+            self.transactionQueue.isCurrentExecutionContext(),
+            "Attempted to access inserted object IDs from a \(typeName(self)) outside its designated queue."
+        )
+        CoreStore.assert(
+            !self.isCommitted,
+            "Attempted to access inserted objects IDs from an already committed \(typeName(self))."
+        )
+        
+        return Set(self.context.insertedObjects.map { $0.objectID })
+    }
+    
+    /**
+     Returns all pending `NSManagedObjectID`s of the specified type that were inserted to the transaction. This method should not be called after the `commit()` method was called.
+     
+     - parameter entity: the `NSManagedObject` subclass to filter
+     - returns: a `Set` of pending `NSManagedObjectID`s of the specified type that were inserted to the transaction.
+     */
+    public func insertedObjectIDs<T: NSManagedObject>(entity: T.Type) -> Set<NSManagedObjectID> {
+        
+        CoreStore.assert(
+            self.transactionQueue.isCurrentExecutionContext(),
+            "Attempted to access inserted object IDs from a \(typeName(self)) outside its designated queue."
+        )
+        CoreStore.assert(
+            !self.isCommitted,
+            "Attempted to access inserted objects IDs from an already committed \(typeName(self))."
+        )
+        
+        return Set(self.context.insertedObjects.flatMap { $0 as? T }.map { $0.objectID })
+    }
+    
+    /**
+     Returns all pending `NSManagedObject`s that were updated in the transaction. This method should not be called after the `commit()` method was called.
+     
+     - returns: a `Set` of pending `NSManagedObject`s that were updated to the transaction.
+     */
+    public func updatedObjects() -> Set<NSManagedObject> {
+        
+        CoreStore.assert(
+            self.transactionQueue.isCurrentExecutionContext(),
+            "Attempted to access updated objects from a \(typeName(self)) outside its designated queue."
+        )
+        CoreStore.assert(
+            !self.isCommitted,
+            "Attempted to access updated objects from an already committed \(typeName(self))."
+        )
+        
+        return self.context.updatedObjects
+    }
+    
+    /**
+     Returns all pending `NSManagedObject`s of the specified type that were updated in the transaction. This method should not be called after the `commit()` method was called.
+     
+     - parameter entity: the `NSManagedObject` subclass to filter
+     - returns: a `Set` of pending `NSManagedObject`s of the specified type that were updated in the transaction.
+     */
+    public func updatedObjects<T: NSManagedObject>(entity: T.Type) -> Set<T> {
+        
+        CoreStore.assert(
+            self.transactionQueue.isCurrentExecutionContext(),
+            "Attempted to access updated objects from a \(typeName(self)) outside its designated queue."
+        )
+        CoreStore.assert(
+            !self.isCommitted,
+            "Attempted to access updated objects from an already committed \(typeName(self))."
+        )
+        
+        return Set(self.context.updatedObjects.flatMap { $0 as? T })
+    }
+    
+    /**
+     Returns all pending `NSManagedObjectID`s that were updated in the transaction. This method should not be called after the `commit()` method was called.
+     
+     - returns: a `Set` of pending `NSManagedObjectID`s that were updated in the transaction.
+     */
+    public func updatedObjectIDs() -> Set<NSManagedObjectID> {
+        
+        CoreStore.assert(
+            self.transactionQueue.isCurrentExecutionContext(),
+            "Attempted to access updated object IDs from a \(typeName(self)) outside its designated queue."
+        )
+        CoreStore.assert(
+            !self.isCommitted,
+            "Attempted to access updated object IDs from an already committed \(typeName(self))."
+        )
+        
+        return Set(self.context.updatedObjects.map { $0.objectID })
+    }
+    
+    /**
+     Returns all pending `NSManagedObjectID`s of the specified type that were updated in the transaction. This method should not be called after the `commit()` method was called.
+     
+     - parameter entity: the `NSManagedObject` subclass to filter
+     - returns: a `Set` of pending `NSManagedObjectID`s of the specified type that were updated in the transaction.
+     */
+    public func updatedObjectIDs<T: NSManagedObject>(entity: T.Type) -> Set<NSManagedObjectID> {
+        
+        CoreStore.assert(
+            self.transactionQueue.isCurrentExecutionContext(),
+            "Attempted to access updated object IDs from a \(typeName(self)) outside its designated queue."
+        )
+        CoreStore.assert(
+            !self.isCommitted,
+            "Attempted to access updated object IDs from an already committed \(typeName(self))."
+        )
+        
+        return Set(self.context.updatedObjects.flatMap { $0 as? T }.map { $0.objectID })
+    }
+    
+    /**
+     Returns all pending `NSManagedObject`s that were deleted from the transaction. This method should not be called after the `commit()` method was called.
+     
+     - returns: a `Set` of pending `NSManagedObject`s that were deleted from the transaction.
+     */
+    public func deletedObjects() -> Set<NSManagedObject> {
+        
+        CoreStore.assert(
+            self.transactionQueue.isCurrentExecutionContext(),
+            "Attempted to access deleted objects from a \(typeName(self)) outside its designated queue."
+        )
+        CoreStore.assert(
+            !self.isCommitted,
+            "Attempted to access deleted objects from an already committed \(typeName(self))."
+        )
+        
+        return self.context.deletedObjects
+    }
+    
+    /**
+     Returns all pending `NSManagedObject`s of the specified type that were deleted from the transaction. This method should not be called after the `commit()` method was called.
+     
+     - parameter entity: the `NSManagedObject` subclass to filter
+     - returns: a `Set` of pending `NSManagedObject`s of the specified type that were deleted from the transaction.
+     */
+    public func deletedObjects<T: NSManagedObject>(entity: T.Type) -> Set<T> {
+        
+        CoreStore.assert(
+            self.transactionQueue.isCurrentExecutionContext(),
+            "Attempted to access deleted objects from a \(typeName(self)) outside its designated queue."
+        )
+        CoreStore.assert(
+            !self.isCommitted,
+            "Attempted to access deleted objects from an already committed \(typeName(self))."
+        )
+        
+        return Set(self.context.deletedObjects.flatMap { $0 as? T })
+    }
+    
+    /**
+     Returns all pending `NSManagedObjectID`s of the specified type that were deleted from the transaction. This method should not be called after the `commit()` method was called.
+     
+     - parameter entity: the `NSManagedObject` subclass to filter
+     - returns: a `Set` of pending `NSManagedObjectID`s of the specified type that were deleted from the transaction.
+     */
+    public func deletedObjectIDs() -> Set<NSManagedObjectID> {
+        
+        CoreStore.assert(
+            self.transactionQueue.isCurrentExecutionContext(),
+            "Attempted to access deleted object IDs from a \(typeName(self)) outside its designated queue."
+        )
+        CoreStore.assert(
+            !self.isCommitted,
+            "Attempted to access deleted object IDs from an already committed \(typeName(self))."
+        )
+        
+        return Set(self.context.deletedObjects.map { $0.objectID })
+    }
+    
+    /**
+     Returns all pending `NSManagedObjectID`s of the specified type that were deleted from the transaction. This method should not be called after the `commit()` method was called.
+     
+     - parameter entity: the `NSManagedObject` subclass to filter
+     - returns: a `Set` of pending `NSManagedObjectID`s of the specified type that were deleted from the transaction.
+     */
+    public func deletedObjectIDs<T: NSManagedObject>(entity: T.Type) -> Set<NSManagedObjectID> {
+        
+        CoreStore.assert(
+            self.transactionQueue.isCurrentExecutionContext(),
+            "Attempted to access deleted object IDs from a \(typeName(self)) outside its designated queue."
+        )
+        CoreStore.assert(
+            !self.isCommitted,
+            "Attempted to access deleted object IDs from an already committed \(typeName(self))."
+        )
+        
+        return Set(self.context.deletedObjects.flatMap { $0 as? T }.map { $0.objectID })
     }
     
     
@@ -203,26 +445,38 @@ public /*abstract*/ class BaseDataTransaction {
     internal let context: NSManagedObjectContext
     internal let transactionQueue: GCDQueue
     internal let childTransactionQueue: GCDQueue = .createSerial("com.corestore.datastack.childtransactionqueue")
+    internal let supportsUndo: Bool
+    internal let bypassesQueueing: Bool
+    
     
     internal var isCommitted = false
     internal var result: SaveResult?
     
-    internal init(mainContext: NSManagedObjectContext, queue: GCDQueue) {
-        
-        self.transactionQueue = queue
+    internal init(mainContext: NSManagedObjectContext, queue: GCDQueue, supportsUndo: Bool, bypassesQueueing: Bool) {
         
         let context = mainContext.temporaryContextInTransactionWithConcurrencyType(
             queue == .Main
                 ? .MainQueueConcurrencyType
                 : .PrivateQueueConcurrencyType
         )
+        self.transactionQueue = queue
         self.context = context
+        self.supportsUndo = supportsUndo
+        self.bypassesQueueing = bypassesQueueing
         
         context.parentTransaction = self
+        if !supportsUndo {
+            
+            context.undoManager = nil
+        }
+        else if context.undoManager == nil {
+            
+            context.undoManager = NSUndoManager()
+        }
     }
     
-    internal var bypassesQueueing: Bool {
+    internal func isRunningInAllowedQueue() -> Bool {
         
-        return false
+        return self.bypassesQueueing || self.transactionQueue.isCurrentExecutionContext()
     }
 }

CoreStore/Saving and Processing/CoreStore+Transaction.swift

@@ -2,7 +2,7 @@
 //  CoreStore+Transaction.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -30,36 +30,51 @@ import Foundation
 
 public extension CoreStore {
     
-    // MARK: Public
-    
     /**
-    Using the `defaultStack`, begins a transaction asynchronously where `NSManagedObject` creates, updates, and deletes can be made.
-    
-    - parameter closure: the block where creates, updates, and deletes can be made to the transaction. Transaction blocks are executed serially in a background queue, and all changes are made from a concurrent `NSManagedObjectContext`.
-    */
+     Using the `defaultStack`, begins a transaction asynchronously where `NSManagedObject` creates, updates, and deletes can be made.
+     
+     - parameter closure: the block where creates, updates, and deletes can be made to the transaction. Transaction blocks are executed serially in a background queue, and all changes are made from a concurrent `NSManagedObjectContext`.
+     */
     public static func beginAsynchronous(closure: (transaction: AsynchronousDataTransaction) -> Void) {
         
         self.defaultStack.beginAsynchronous(closure)
     }
     
     /**
-    Using the `defaultStack`, begins a transaction asynchronously where `NSManagedObject` creates, updates, and deletes can be made.
-    
-    - parameter closure: the block where creates, updates, and deletes can be made to the transaction. Transaction blocks are executed serially in a background queue, and all changes are made from a concurrent `NSManagedObjectContext`.
-    - returns: a `SaveResult` value indicating success or failure, or `nil` if the transaction was not comitted synchronously
-    */
+     Using the `defaultStack`, begins a transaction asynchronously where `NSManagedObject` creates, updates, and deletes can be made.
+     
+     - parameter closure: the block where creates, updates, and deletes can be made to the transaction. Transaction blocks are executed serially in a background queue, and all changes are made from a concurrent `NSManagedObjectContext`.
+     - returns: a `SaveResult` value indicating success or failure, or `nil` if the transaction was not comitted synchronously
+     */
     public static func beginSynchronous(closure: (transaction: SynchronousDataTransaction) -> Void) -> SaveResult? {
         
         return self.defaultStack.beginSynchronous(closure)
     }
     
     /**
-    Using the `defaultStack`, begins a non-contiguous transaction where `NSManagedObject` creates, updates, and deletes can be made. This is useful for making temporary changes, such as partially filled forms. A detached transaction object should typically be only used from the main queue.
-    
-    - returns: a `DetachedDataTransaction` instance where creates, updates, and deletes can be made.
-    */
-    public static func beginDetached() -> DetachedDataTransaction {
+     Using the `defaultStack`, begins a non-contiguous transaction where `NSManagedObject` creates, updates, and deletes can be made. This is useful for making temporary changes, such as partially filled forms. An unsafe transaction object should typically be only used from the main queue.
+     
+     - prameter supportsUndo: `undo()`, `redo()`, and `rollback()` methods are only available when this parameter is `true`, otherwise those method will raise an exception. Defaults to `false`. Note that turning on Undo support may heavily impact performance especially on iOS or watchOS where memory is limited.
+     - returns: a `UnsafeDataTransaction` instance where creates, updates, and deletes can be made.
+     */
+    @warn_unused_result
+    public static func beginUnsafe(supportsUndo supportsUndo: Bool = false) -> UnsafeDataTransaction {
         
-        return self.defaultStack.beginDetached()
+        return self.defaultStack.beginUnsafe(supportsUndo: supportsUndo)
+    }
+    
+    /**
+     Refreshes all registered objects `NSManagedObject`s in the `DataStack`.
+     */
+    public static func refreshAndMergeAllObjects() {
+        
+        self.defaultStack.refreshAndMergeAllObjects()
+    }
+    
+    @available(*, deprecated=1.3.1, renamed="beginUnsafe")
+    @warn_unused_result
+    public static func beginDetached() -> UnsafeDataTransaction {
+        
+        return self.beginUnsafe()
     }
 }

CoreStore/Saving and Processing/DataStack+Transaction.swift

@@ -2,7 +2,7 @@
 //  DataStack+Transaction.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -25,20 +25,20 @@
 
 import Foundation
 import CoreData
-import GCDKit
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
 
 
 // MARK: - DataStack
 
 public extension DataStack {
     
-    // MARK: Public
-    
     /**
-    Begins a transaction asynchronously where `NSManagedObject` creates, updates, and deletes can be made.
-    
-    - parameter closure: the block where creates, updates, and deletes can be made to the transaction. Transaction blocks are executed serially in a background queue, and all changes are made from a concurrent `NSManagedObjectContext`.
-    */
+     Begins a transaction asynchronously where `NSManagedObject` creates, updates, and deletes can be made.
+     
+     - parameter closure: the block where creates, updates, and deletes can be made to the transaction. Transaction blocks are executed serially in a background queue, and all changes are made from a concurrent `NSManagedObjectContext`.
+     */
     public func beginAsynchronous(closure: (transaction: AsynchronousDataTransaction) -> Void) {
         
         AsynchronousDataTransaction(
@@ -48,11 +48,11 @@ public extension DataStack {
     }
     
     /**
-    Begins a transaction synchronously where `NSManagedObject` creates, updates, and deletes can be made.
-    
-    - parameter closure: the block where creates, updates, and deletes can be made to the transaction. Transaction blocks are executed serially in a background queue, and all changes are made from a concurrent `NSManagedObjectContext`.
-    - returns: a `SaveResult` value indicating success or failure, or `nil` if the transaction was not comitted synchronously
-    */
+     Begins a transaction synchronously where `NSManagedObject` creates, updates, and deletes can be made.
+     
+     - parameter closure: the block where creates, updates, and deletes can be made to the transaction. Transaction blocks are executed serially in a background queue, and all changes are made from a concurrent `NSManagedObjectContext`.
+     - returns: a `SaveResult` value indicating success or failure, or `nil` if the transaction was not comitted synchronously
+     */
     public func beginSynchronous(closure: (transaction: SynchronousDataTransaction) -> Void) -> SaveResult? {
         
         return SynchronousDataTransaction(
@@ -62,14 +62,41 @@ public extension DataStack {
     }
     
     /**
-    Begins a non-contiguous transaction where `NSManagedObject` creates, updates, and deletes can be made. This is useful for making temporary changes, such as partially filled forms. A detached transaction object should typically be only used from the main queue.
-    
-    - returns: a `DetachedDataTransaction` instance where creates, updates, and deletes can be made.
-    */
-    public func beginDetached() -> DetachedDataTransaction {
+     Begins a non-contiguous transaction where `NSManagedObject` creates, updates, and deletes can be made. This is useful for making temporary changes, such as partially filled forms.
+     
+     - prameter supportsUndo: `undo()`, `redo()`, and `rollback()` methods are only available when this parameter is `true`, otherwise those method will raise an exception. Defaults to `false`. Note that turning on Undo support may heavily impact performance especially on iOS or watchOS where memory is limited.
+     - returns: a `UnsafeDataTransaction` instance where creates, updates, and deletes can be made.
+     */
+    @warn_unused_result
+    public func beginUnsafe(supportsUndo supportsUndo: Bool = false) -> UnsafeDataTransaction {
         
-        return DetachedDataTransaction(
+        return UnsafeDataTransaction(
             mainContext: self.rootSavingContext,
-            queue: .Main)
+            queue: .createSerial(
+                "com.coreStore.dataStack.unsafeTransactionQueue",
+                targetQueue: .UserInitiated
+            ),
+            supportsUndo: supportsUndo
+        )
+    }
+    
+    /**
+     Refreshes all registered objects `NSManagedObject`s in the `DataStack`.
+     */
+    public func refreshAndMergeAllObjects() {
+        
+        CoreStore.assert(
+            NSThread.isMainThread(),
+            "Attempted to refresh entities outside their designated queue."
+        )
+        
+        self.mainContext.refreshAndMergeAllObjects()
+    }
+    
+    @available(*, deprecated=1.3.1, renamed="beginUnsafe")
+    @warn_unused_result
+    public func beginDetached() -> UnsafeDataTransaction {
+        
+        return self.beginUnsafe()
     }
 }

CoreStore/Saving and Processing/Into.swift

@@ -2,7 +2,7 @@
 //  Into.swift
 //  CoreStore
 //
-//  Copyright (c) 2014 John Rommel Estropia
+//  Copyright © 2014 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -30,26 +30,24 @@ import CoreData
 // MARK: - Into
 
 /**
-A `Into` clause contains the destination entity and destination persistent store for a `create(...)` method. A common usage is to just indicate the entity:
-
-let person = transaction.create(Into(MyPersonEntity))
-
-For cases where multiple `NSPersistentStore`s contain the same entity, the destination configuration's name needs to be specified as well:
-
-let person = transaction.create(Into<MyPersonEntity>("Configuration1"))
-
-This helps the `NSManagedObjectContext` to determine which
-*/
+ An `Into` clause contains the destination entity and destination persistent store for a `create(...)` method. A common usage is to just indicate the entity:
+ ```
+ let person = transaction.create(Into(MyPersonEntity))
+ ```
+ For cases where multiple `NSPersistentStore`s contain the same entity, the destination configuration's name needs to be specified as well:
+ ```
+ let person = transaction.create(Into<MyPersonEntity>("Configuration1"))
+ ```
+ */
 public struct Into<T: NSManagedObject> {
     
-    // MARK: Public
-    
     /**
-    Initializes an `Into` clause.
-    Sample Usage:
-    
-    let person = transaction.create(Into<MyPersonEntity>())
-    */
+     Initializes an `Into` clause.
+     Sample Usage:
+     ```
+     let person = transaction.create(Into<MyPersonEntity>())
+     ```
+     */
     public init(){
         
         self.configuration = nil
@@ -58,13 +56,13 @@ public struct Into<T: NSManagedObject> {
     }
     
     /**
-    Initializes an `Into` clause with the specified entity type.
-    Sample Usage:
-    
-    let person = transaction.create(Into(MyPersonEntity))
-    
-    - parameter entity: the `NSManagedObject` type to be created
-    */
+     Initializes an `Into` clause with the specified entity type.
+     Sample Usage:
+     ```
+     let person = transaction.create(Into(MyPersonEntity))
+     ```
+     - parameter entity: the `NSManagedObject` type to be created
+     */
     public init(_ entity: T.Type) {
         
         self.configuration = nil
@@ -73,10 +71,13 @@ public struct Into<T: NSManagedObject> {
     }
     
     /**
-    Initializes an `Into` clause with the specified entity class.
-    
-    - parameter entityClass: the `NSManagedObject` class type to be created
-    */
+     Initializes an `Into` clause with the specified entity class.
+     Sample Usage:
+     ```
+     let person = transaction.create(Into(MyPersonEntity))
+     ```
+     - parameter entityClass: the `NSManagedObject` class type to be created
+     */
     public init(_ entityClass: AnyClass) {
         
         self.configuration = nil
@@ -85,13 +86,13 @@ public struct Into<T: NSManagedObject> {
     }
     
     /**
-    Initializes an `Into` clause with the specified configuration.
-    Sample Usage:
-    
-    let person = transaction.create(Into<MyPersonEntity>("Configuration1"))
-    
-    - parameter configuration: the `NSPersistentStore` configuration name to associate the object to. This parameter is required if multiple configurations contain the created `NSManagedObject`'s entity type. Set to `nil` to use the default configuration.
-    */
+     Initializes an `Into` clause with the specified configuration.
+     Sample Usage:
+     ```
+     let person = transaction.create(Into<MyPersonEntity>("Configuration1"))
+     ```
+     - parameter configuration: the `NSPersistentStore` configuration name to associate the object to. This parameter is required if multiple configurations contain the created `NSManagedObject`'s entity type. Set to `nil` to use the default configuration.
+     */
     public init(_ configuration: String?) {
         
         self.configuration = configuration
@@ -100,14 +101,14 @@ public struct Into<T: NSManagedObject> {
     }
     
     /**
-    Initializes an `Into` clause with the specified entity type and configuration.
-    Sample Usage:
-    
-    let person = transaction.create(Into(MyPersonEntity.self, "Configuration1"))
-    
-    - parameter entity: the `NSManagedObject` type to be created
-    - parameter configuration: the `NSPersistentStore` configuration name to associate the object to. This parameter is required if multiple configurations contain the created `NSManagedObject`'s entity type. Set to `nil` to use the default configuration.
-    */
+     Initializes an `Into` clause with the specified entity type and configuration.
+     Sample Usage:
+     ```
+     let person = transaction.create(Into(MyPersonEntity.self, "Configuration1"))
+     ```
+     - parameter entity: the `NSManagedObject` type to be created
+     - parameter configuration: the `NSPersistentStore` configuration name to associate the object to. This parameter is required if multiple configurations contain the created `NSManagedObject`'s entity type. Set to `nil` to use the default configuration.
+     */
     public init(_ entity: T.Type, _ configuration: String?) {
         
         self.configuration = configuration
@@ -116,14 +117,14 @@ public struct Into<T: NSManagedObject> {
     }
     
     /**
-    Initializes an `Into` clause with the specified entity class and configuration.
-    Sample Usage:
-    
-    let person = transaction.create(Into(MyPersonEntity.self, "Configuration1"))
-    
-    - parameter entityClass: the `NSManagedObject` class type to be created
-    - parameter configuration: the `NSPersistentStore` configuration name to associate the object to. This parameter is required if multiple configurations contain the created `NSManagedObject`'s entity type. Set to `nil` to use the default configuration.
-    */
+     Initializes an `Into` clause with the specified entity class and configuration.
+     Sample Usage:
+     ```
+     let person = transaction.create(Into(MyPersonEntity.self, "Configuration1"))
+     ```
+     - parameter entityClass: the `NSManagedObject` class type to be created
+     - parameter configuration: the `NSPersistentStore` configuration name to associate the object to. This parameter is required if multiple configurations contain the created `NSManagedObject`'s entity type. Set to `nil` to use the default configuration.
+     */
     public init(_ entityClass: AnyClass, _ configuration: String?) {
         
         self.configuration = configuration

CoreStore/Saving and Processing/NSManagedObject+Transaction.swift

@@ -0,0 +1,61 @@
+//
+//  NSManagedObject+Transaction.swift
+//  CoreStore
+//
+//  Copyright © 2016 John Rommel Estropia
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+//
+
+import Foundation
+import CoreData
+
+
+// MARK: - NSManagedObject
+
+public extension NSManagedObject {
+    
+    /**
+     Returns this object's parent `UnsafeDataTransaction` instance if it was created from one. Returns `nil` if the parent transaction is either an `AsynchronousDataTransaction` or a `SynchronousDataTransaction`, or if the object is not managed by CoreStore.
+     
+     When using an `UnsafeDataTransaction` and passing around a temporary object, you can use this property to execute fetches and updates to the transaction without having to pass around both the object and the transaction instances.
+     
+     Note that the internal reference to the transaction is `weak`, and it is still the developer's responsibility to retain a strong reference to the `UnsafeDataTransaction`.
+     */
+    public var unsafeDataTransaction: UnsafeDataTransaction? {
+        
+        return self.managedObjectContext?.parentTransaction as? UnsafeDataTransaction
+    }
+    
+    
+    // MARK: Internal
+    
+    internal dynamic class func createInContext(context: NSManagedObjectContext) -> Self {
+        
+        return self.init(
+            entity: context.entityDescriptionForEntityType(self)!,
+            insertIntoManagedObjectContext: context
+        )
+    }
+    
+    internal func deleteFromContext() {
+        
+        self.managedObjectContext?.deleteObject(self)
+    }
+}

CoreStore/Saving and Processing/SaveResult.swift

@@ -2,7 +2,7 @@
 //  SaveResult.swift
 //  CoreStore
 //
-//  Copyright (c) 2014 John Rommel Estropia
+//  Copyright © 2014 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -29,46 +29,44 @@ import Foundation
 // MARK: - SaveResult
 
 /**
-The `SaveResult` indicates the result of a `commit(...)` for a transaction.
-The `SaveResult` can be treated as a boolean:
-
-    CoreStore.beginAsynchronous { transaction in
-        // ...
-        let result = transaction.commit()
-        if result {
-            // succeeded
-        }
-        else {
-            // failed
-        }
-    }
-
-or as an `enum`, where the resulting associated object can also be inspected:
-
-    CoreStore.beginAsynchronous { transaction in
-        // ...
-        let result = transaction.commit()
-        switch result {
-        case .Success(let hasChanges):
-            // hasChanges indicates if there were changes or not
-        case .Failure(let error):
-            // error is the NSError instance for the failure
-        }
-    }
-```
-*/
+ The `SaveResult` indicates the result of a `commit(...)` for a transaction.
+ The `SaveResult` can be treated as a boolean:
+ ```
+ CoreStore.beginAsynchronous { transaction in
+     // ...
+     let result = transaction.commit()
+     if result {
+        // succeeded
+     }
+     else {
+        // failed
+     }
+ }
+ ```
+ or as an `enum`, where the resulting associated object can also be inspected:
+ ```
+ CoreStore.beginAsynchronous { transaction in
+     // ...
+     let result = transaction.commit()
+     switch result {
+     case .Success(let hasChanges):
+        // hasChanges indicates if there were changes or not
+     case .Failure(let error):
+        // error is the NSError instance for the failure
+     }
+ }
+ ```
+ */
 public enum SaveResult {
     
-    // MARK: Public
-    
     /**
-    `SaveResult.Success` indicates that the `commit()` for the transaction succeeded, either because the save succeeded or because there were no changes to save. The associated value `hasChanges` indicates if there were saved changes or not.
-    */
+     `SaveResult.Success` indicates that the `commit()` for the transaction succeeded, either because the save succeeded or because there were no changes to save. The associated value `hasChanges` indicates if there were saved changes or not.
+     */
     case Success(hasChanges: Bool)
     
     /**
-    `SaveResult.Failure` indicates that the `commit()` for the transaction failed. The associated object for this value is the related `NSError` instance.
-    */
+     `SaveResult.Failure` indicates that the `commit()` for the transaction failed. The associated object for this value is the related `NSError` instance.
+     */
     case Failure(NSError)
     
     
@@ -103,6 +101,7 @@ extension SaveResult: BooleanType {
     public var boolValue: Bool {
         
         switch self {
+            
         case .Success: return true
         case .Failure: return false
         }

CoreStore/Saving and Processing/SynchronousDataTransaction.swift

@@ -2,7 +2,7 @@
 //  SynchronousDataTransaction.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -25,22 +25,24 @@
 
 import Foundation
 import CoreData
-import GCDKit
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
 
 
 // MARK: - SynchronousDataTransaction
 
 /**
-The `SynchronousDataTransaction` provides an interface for `NSManagedObject` creates, updates, and deletes. A transaction object should typically be only used from within a transaction block initiated from `DataStack.beginSynchronous(_:)`, or from `CoreStore.beginSynchronous(_:)`.
-*/
+ The `SynchronousDataTransaction` provides an interface for `NSManagedObject` creates, updates, and deletes. A transaction object should typically be only used from within a transaction block initiated from `DataStack.beginSynchronous(_:)`, or from `CoreStore.beginSynchronous(_:)`.
+ */
 public final class SynchronousDataTransaction: BaseDataTransaction {
     
-    // MARK: Public
-    
     /**
-    Saves the transaction changes and waits for completion synchronously. This method should not be used after the `commit()` method was already called once.
-    */
-    public func commit() {
+     Saves the transaction changes and waits for completion synchronously. This method should not be used after the `commit()` method was already called once.
+     
+     - returns: a `SaveResult` containing the success or failure information
+     */
+    public func commitAndWait() -> SaveResult {
         
         CoreStore.assert(
             self.transactionQueue.isCurrentExecutionContext(),
@@ -52,15 +54,18 @@ public final class SynchronousDataTransaction: BaseDataTransaction {
         )
         
         self.isCommitted = true
-        self.result = self.context.saveSynchronously()
+        
+        let result = self.context.saveSynchronously()
+        self.result = result
+        return result
     }
     
     /**
-    Begins a child transaction synchronously where `NSManagedObject` creates, updates, and deletes can be made. This method should not be used after the `commit()` method was already called once.
-    
-    - parameter closure: the block where creates, updates, and deletes can be made to the transaction. Transaction blocks are executed serially in a background queue, and all changes are made from a concurrent `NSManagedObjectContext`.
-    - returns: a `SaveResult` value indicating success or failure, or `nil` if the transaction was not comitted synchronously
-    */
+     Begins a child transaction synchronously where `NSManagedObject` creates, updates, and deletes can be made. This method should not be used after the `commit()` method was already called once.
+     
+     - parameter closure: the block where creates, updates, and deletes can be made to the transaction. Transaction blocks are executed serially in a background queue, and all changes are made from a concurrent `NSManagedObjectContext`.
+     - returns: a `SaveResult` value indicating success or failure, or `nil` if the transaction was not comitted synchronously
+     */
     public func beginSynchronous(closure: (transaction: SynchronousDataTransaction) -> Void) -> SaveResult? {
         
         CoreStore.assert(
@@ -82,11 +87,11 @@ public final class SynchronousDataTransaction: BaseDataTransaction {
     // MARK: BaseDataTransaction
     
     /**
-    Creates a new `NSManagedObject` with the specified entity type.
-    
-    - parameter into: the `Into` clause indicating the destination `NSManagedObject` entity type and the destination configuration
-    - returns: a new `NSManagedObject` instance of the specified entity type.
-    */
+     Creates a new `NSManagedObject` with the specified entity type.
+     
+     - parameter into: the `Into` clause indicating the destination `NSManagedObject` entity type and the destination configuration
+     - returns: a new `NSManagedObject` instance of the specified entity type.
+     */
     public override func create<T: NSManagedObject>(into: Into<T>) -> T {
         
         CoreStore.assert(
@@ -98,11 +103,12 @@ public final class SynchronousDataTransaction: BaseDataTransaction {
     }
     
     /**
-    Returns an editable proxy of a specified `NSManagedObject`. This method should not be used after the `commit()` method was already called once.
-    
-    - parameter object: the `NSManagedObject` type to be edited
-    - returns: an editable proxy for the specified `NSManagedObject`.
-    */
+     Returns an editable proxy of a specified `NSManagedObject`. This method should not be used after the `commit()` method was already called once.
+     
+     - parameter object: the `NSManagedObject` type to be edited
+     - returns: an editable proxy for the specified `NSManagedObject`.
+     */
+    @warn_unused_result
     public override func edit<T: NSManagedObject>(object: T?) -> T? {
         
         CoreStore.assert(
@@ -114,12 +120,13 @@ public final class SynchronousDataTransaction: BaseDataTransaction {
     }
     
     /**
-    Returns an editable proxy of the object with the specified `NSManagedObjectID`. This method should not be used after the `commit()` method was already called once.
-    
-    - parameter into: an `Into` clause specifying the entity type
-    - parameter objectID: the `NSManagedObjectID` for the object to be edited
-    - returns: an editable proxy for the specified `NSManagedObject`.
-    */
+     Returns an editable proxy of the object with the specified `NSManagedObjectID`. This method should not be used after the `commit()` method was already called once.
+     
+     - parameter into: an `Into` clause specifying the entity type
+     - parameter objectID: the `NSManagedObjectID` for the object to be edited
+     - returns: an editable proxy for the specified `NSManagedObject`.
+     */
+    @warn_unused_result
     public override func edit<T: NSManagedObject>(into: Into<T>, _ objectID: NSManagedObjectID) -> T? {
         
         CoreStore.assert(
@@ -131,10 +138,10 @@ public final class SynchronousDataTransaction: BaseDataTransaction {
     }
     
     /**
-    Deletes a specified `NSManagedObject`. This method should not be used after the `commit()` method was already called once.
-    
-    - parameter object: the `NSManagedObject` type to be deleted
-    */
+     Deletes a specified `NSManagedObject`. This method should not be used after the `commit()` method was already called once.
+     
+     - parameter object: the `NSManagedObject` type to be deleted
+     */
     public override func delete(object: NSManagedObject?) {
         
         CoreStore.assert(
@@ -146,12 +153,12 @@ public final class SynchronousDataTransaction: BaseDataTransaction {
     }
     
     /**
-    Deletes the specified `NSManagedObject`s.
-    
-    - parameter object1: the `NSManagedObject` to be deleted
-    - parameter object2: another `NSManagedObject` to be deleted
-    - parameter objects: other `NSManagedObject`s to be deleted
-    */
+     Deletes the specified `NSManagedObject`s.
+     
+     - parameter object1: the `NSManagedObject` to be deleted
+     - parameter object2: another `NSManagedObject` to be deleted
+     - parameter objects: other `NSManagedObject`s to be deleted
+     */
     public override func delete(object1: NSManagedObject?, _ object2: NSManagedObject?, _ objects: NSManagedObject?...) {
         
         CoreStore.assert(
@@ -159,15 +166,15 @@ public final class SynchronousDataTransaction: BaseDataTransaction {
             "Attempted to delete an entities from an already committed \(typeName(self))."
         )
         
-        super.delete([object1, object2] + objects)
+        super.delete(([object1, object2] + objects).flatMap { $0 })
     }
     
     /**
-    Deletes the specified `NSManagedObject`s.
-    
-    - parameter objects: the `NSManagedObject`s to be deleted
-    */
-    public override func delete(objects: [NSManagedObject?]) {
+     Deletes the specified `NSManagedObject`s.
+     
+     - parameter objects: the `NSManagedObject`s to be deleted
+     */
+    public override func delete<S: SequenceType where S.Generator.Element: NSManagedObject>(objects: S) {
         
         CoreStore.assert(
             !self.isCommitted,
@@ -178,21 +185,39 @@ public final class SynchronousDataTransaction: BaseDataTransaction {
     }
     
     /**
-    Rolls back the transaction by resetting the `NSManagedObjectContext`. After calling this method, all `NSManagedObjects` fetched within the transaction will become invalid. This method should not be used after the `commit()` method was already called once.
-    */
-    public override func rollback() {
+     Rolls back the transaction by resetting the `NSManagedObjectContext`. After calling this method, all `NSManagedObjects` fetched within the transaction will become invalid. This method should not be used after the `commit()` method was already called once.
+     */
+    @available(*, deprecated=1.3.4, message="Resetting the context is inherently unsafe. This method will be removed in the near future. Use `beginUnsafe()` to create transactions with `undo` support.")
+    public func rollback() {
         
         CoreStore.assert(
             !self.isCommitted,
             "Attempted to rollback an already committed \(typeName(self))."
         )
+        CoreStore.assert(
+            self.transactionQueue.isCurrentExecutionContext(),
+            "Attempted to rollback a \(typeName(self)) outside its designated queue."
+        )
         
-        super.rollback()
+        self.context.reset()
+    }
+    
+    @available(*, deprecated=1.5.2, renamed="commitAndWait")
+    public func commit() {
+        
+        self.commitAndWait()
     }
     
     
     // MARK: Internal
     
+    internal init(mainContext: NSManagedObjectContext, queue: GCDQueue, closure: (transaction: SynchronousDataTransaction) -> Void) {
+        
+        self.closure = closure
+        
+        super.init(mainContext: mainContext, queue: queue, supportsUndo: false, bypassesQueueing: false)
+    }
+    
     internal func performAndWait() -> SaveResult? {
         
         self.transactionQueue.sync {
@@ -210,13 +235,6 @@ public final class SynchronousDataTransaction: BaseDataTransaction {
         return self.result
     }
     
-    internal init(mainContext: NSManagedObjectContext, queue: GCDQueue, closure: (transaction: SynchronousDataTransaction) -> Void) {
-        
-        self.closure = closure
-        
-        super.init(mainContext: mainContext, queue: queue)
-    }
-    
     
     // MARK: Private
     

CoreStore/Saving and Processing/UnsafeDataTransaction.swift

@@ -0,0 +1,172 @@
+//
+//  UnsafeDataTransaction.swift
+//  CoreStore
+//
+//  Copyright © 2015 John Rommel Estropia
+//
+//  Permission is hereby granted, free of charge, to any person obtaining a copy
+//  of this software and associated documentation files (the "Software"), to deal
+//  in the Software without restriction, including without limitation the rights
+//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+//  copies of the Software, and to permit persons to whom the Software is
+//  furnished to do so, subject to the following conditions:
+//
+//  The above copyright notice and this permission notice shall be included in all
+//  copies or substantial portions of the Software.
+//
+//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+//  SOFTWARE.
+//
+
+import Foundation
+import CoreData
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
+
+
+@available(*, deprecated=1.3.1, renamed="UnsafeDataTransaction")
+public typealias DetachedDataTransaction = UnsafeDataTransaction
+
+
+// MARK: - UnsafeDataTransaction
+
+/**
+ The `UnsafeDataTransaction` provides an interface for non-contiguous `NSManagedObject` creates, updates, and deletes. This is useful for making temporary changes, such as partially filled forms. An unsafe transaction object should typically be only used from the main queue.
+ */
+public final class UnsafeDataTransaction: BaseDataTransaction {
+    
+    /**
+     Saves the transaction changes asynchronously. For a `UnsafeDataTransaction`, multiple commits are allowed, although it is the developer's responsibility to ensure a reasonable leeway to prevent blocking the main thread.
+     
+     - parameter completion: the block executed after the save completes. Success or failure is reported by the `SaveResult` argument of the block.
+     */
+    public func commit(completion: (result: SaveResult) -> Void) {
+        
+        self.context.saveAsynchronouslyWithCompletion { (result) -> Void in
+            
+            self.result = result
+            completion(result: result)
+        }
+    }
+    
+    /**
+     Saves the transaction changes and waits for completion synchronously. For a `UnsafeDataTransaction`, multiple commits are allowed, although it is the developer's responsibility to ensure a reasonable leeway to prevent blocking the main thread.
+     
+     - returns: a `SaveResult` containing the success or failure information
+     */
+    public func commitAndWait() -> SaveResult {
+        
+        let result = self.context.saveSynchronously()
+        self.result = result
+        return result
+    }
+    
+    /**
+     Rolls back the transaction.
+     */
+    public func rollback() {
+        
+        CoreStore.assert(
+            self.supportsUndo,
+            "Attempted to rollback a \(typeName(self)) with Undo support disabled."
+        )
+        self.context.rollback()
+    }
+    
+    /**
+     Undo's the last change made to the transaction.
+     */
+    public func undo() {
+        
+        CoreStore.assert(
+            self.supportsUndo,
+            "Attempted to undo a \(typeName(self)) with Undo support disabled."
+        )
+        self.context.undo()
+    }
+    
+    /**
+     Immediately flushes all pending changes to the transaction's observers. This is useful in conjunction with `ListMonitor`s and `ObjectMonitor`s created from `UnsafeDataTransaction`s used to manage temporary "scratch" data.
+     
+     - Important: Note that unlike `commit()`, `flush()` does not propagate/save updates to the `DataStack` and the persistent store. However, the flushed changes will be seen by children transactions created further from the current transaction (i.e. through `transaction.beginUnsafe()`)
+     - throws: an error thrown from `closure`, or an error thrown by Core Data (usually validation errors or conflict errors)
+     */
+    public func flush() throws {
+        
+        try self.context.save()
+    }
+    
+    /**
+     Flushes all pending changes to the transaction's observers at the end of the `closure`'s execution. This is useful in conjunction with `ListMonitor`s and `ObjectMonitor`s created from `UnsafeDataTransaction`s used to manage temporary "scratch" data.
+     
+     - Important: Note that unlike `commit()`, `flush()` does not propagate/save updates to the `DataStack` and the persistent store. However, the flushed changes will be seen by children transactions created further from the current transaction (i.e. through `transaction.beginUnsafe()`)
+     - parameter closure: the closure where changes can be made prior to the flush
+     - throws: an error thrown from `closure`, or an error thrown by Core Data (usually validation errors or conflict errors)
+     */
+    public func flush(@noescape closure: () throws -> Void) throws {
+        
+        try closure()
+        try self.context.save()
+    }
+    
+    /**
+     Redo's the last undone change to the transaction.
+     */
+    public func redo() {
+        
+        CoreStore.assert(
+            self.supportsUndo,
+            "Attempted to redo a \(typeName(self)) with Undo support disabled."
+        )
+        self.context.redo()
+    }
+    
+    /**
+     Begins a child transaction where `NSManagedObject` creates, updates, and deletes can be made. This is useful for making temporary changes, such as partially filled forms.
+     
+     - prameter supportsUndo: `undo()`, `redo()`, and `rollback()` methods are only available when this parameter is `true`, otherwise those method will raise an exception. Defaults to `false`. Note that turning on Undo support may heavily impact performance especially on iOS or watchOS where memory is limited.
+     - returns: a `UnsafeDataTransaction` instance where creates, updates, and deletes can be made.
+     */
+    @warn_unused_result
+    public func beginUnsafe(supportsUndo supportsUndo: Bool = false) -> UnsafeDataTransaction {
+        
+        return UnsafeDataTransaction(
+            mainContext: self.context,
+            queue: self.transactionQueue,
+            supportsUndo: supportsUndo
+        )
+    }
+    
+    /**
+     Returns the `NSManagedObjectContext` for this unsafe transaction. Use only for cases where external frameworks need an `NSManagedObjectContext` instance to work with.
+     
+     - Important: Note that it is the developer's responsibility to ensure the following:
+     - that the `UnsafeDataTransaction` that owns this context should be strongly referenced and prevented from being deallocated during the context's lifetime
+     - that all saves will be done either through the `UnsafeDataTransaction`'s `commit(...)` method, or by calling `save()` manually on the context, its parent, and all other ancestor contexts if there are any.
+     */
+    public var internalContext: NSManagedObjectContext {
+        
+        return self.context
+    }
+    
+    @available(*, deprecated=1.3.1, renamed="beginUnsafe")
+    @warn_unused_result
+    public func beginDetached() -> UnsafeDataTransaction {
+        
+        return self.beginUnsafe()
+    }
+    
+    
+    // MARK: Internal
+    
+    internal init(mainContext: NSManagedObjectContext, queue: GCDQueue, supportsUndo: Bool) {
+        
+        super.init(mainContext: mainContext, queue: queue, supportsUndo: supportsUndo, bypassesQueueing: true)
+    }
+}

CoreStore/Setting Up/CoreStore+Setup.swift

@@ -2,7 +2,7 @@
 //  CoreStore+Setup.swift
 //  CoreStore
 //
-//  Copyright (c) 2015 John Rommel Estropia
+//  Copyright © 2015 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -25,7 +25,9 @@
 
 import Foundation
 import CoreData
-import GCDKit
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
 
 
 // MARK: - CoreStore
@@ -33,24 +35,48 @@ import GCDKit
 public extension CoreStore {
     
     /**
-    Adds an in-memory store to the `defaultStack`.
+     Returns the `defaultStack`'s model version. The version string is the same as the name of the version-specific .xcdatamodeld file.
+     */
+    public static var modelVersion: String {
+        
+        return self.defaultStack.modelVersion
+    }
     
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`.
-    - returns: the `NSPersistentStore` added to the stack.
-    */
+    /**
+     Returns the entity name-to-class type mapping from the `defaultStack`'s model.
+     */
+    public static var entityTypesByName: [String: NSManagedObject.Type] {
+        
+        return self.defaultStack.entityTypesByName
+    }
+    
+    /**
+     Returns the `NSEntityDescription` for the specified `NSManagedObject` subclass from `defaultStack`'s model.
+     */
+    public static func entityDescriptionForType(type: NSManagedObject.Type) -> NSEntityDescription? {
+        
+        return self.defaultStack.entityDescriptionForType(type)
+    }
+    
+    /**
+     Adds an in-memory store to the `defaultStack`.
+     
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`.
+     - returns: the `NSPersistentStore` added to the stack.
+     */
     public static func addInMemoryStoreAndWait(configuration configuration: String? = nil) throws -> NSPersistentStore {
         
         return try self.defaultStack.addInMemoryStoreAndWait(configuration: configuration)
     }
     
     /**
-    Adds to the `defaultStack` an SQLite store from the given SQLite file name.
-    
-    - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory. A new SQLite file will be created if it does not exist.
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to nil.
-    - parameter resetStoreOnModelMismatch: Set to true to delete the store on model mismatch; or set to false to throw exceptions on failure instead. Typically should only be set to true when debugging, or if the persistent store can be recreated easily. If not specified, defaults to false
-    - returns: the `NSPersistentStore` added to the stack.
-    */
+     Adds to the `defaultStack` an SQLite store from the given SQLite file name.
+     
+     - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory (or the "Caches" directory on tvOS). A new SQLite file will be created if it does not exist.
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to nil.
+     - parameter resetStoreOnModelMismatch: Set to true to delete the store on model mismatch; or set to false to throw exceptions on failure instead. Typically should only be set to true when debugging, or if the persistent store can be recreated easily. If not specified, defaults to false
+     - returns: the `NSPersistentStore` added to the stack.
+     */
     public static func addSQLiteStoreAndWait(fileName fileName: String, configuration: String? = nil, resetStoreOnModelMismatch: Bool = false) throws -> NSPersistentStore {
         
         return try self.defaultStack.addSQLiteStoreAndWait(
@@ -61,13 +87,13 @@ public extension CoreStore {
     }
     
     /**
-    Adds to the `defaultStack` an SQLite store from the given SQLite file URL.
-    
-    - parameter fileURL: the local file URL for the SQLite persistent store. A new SQLite file will be created if it does not exist. If not specified, defaults to a file URL pointing to a "<Application name>.sqlite" file in the "Application Support" directory.
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to nil.
-    - parameter resetStoreOnModelMismatch: Set to true to delete the store on model mismatch; or set to false to throw exceptions on failure instead. Typically should only be set to true when debugging, or if the persistent store can be recreated easily. If not specified, defaults to false.
-    - returns: the `NSPersistentStore` added to the stack.
-    */
+     Adds to the `defaultStack` an SQLite store from the given SQLite file URL.
+     
+     - parameter fileURL: the local file URL for the SQLite persistent store. A new SQLite file will be created if it does not exist. If not specified, defaults to a file URL pointing to a "<Application name>.sqlite" file in the "Application Support" directory (or the "Caches" directory on tvOS).
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to nil.
+     - parameter resetStoreOnModelMismatch: Set to true to delete the store on model mismatch; or set to false to throw exceptions on failure instead. Typically should only be set to true when debugging, or if the persistent store can be recreated easily. If not specified, defaults to false.
+     - returns: the `NSPersistentStore` added to the stack.
+     */
     public static func addSQLiteStoreAndWait(fileURL: NSURL = defaultSQLiteStoreURL, configuration: String? = nil, resetStoreOnModelMismatch: Bool = false) throws -> NSPersistentStore {
         
         return try self.defaultStack.addSQLiteStoreAndWait(

CoreStore/Setting Up/DataStack.swift

@@ -2,7 +2,7 @@
 //  DataStack.swift
 //  CoreStore
 //
-//  Copyright (c) 2014 John Rommel Estropia
+//  Copyright © 2014 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -25,32 +25,38 @@
 
 import Foundation
 import CoreData
-import GCDKit
+#if USE_FRAMEWORKS
+    import GCDKit
+#endif
 
 
-internal let applicationSupportDirectory = NSFileManager.defaultManager().URLsForDirectory(.ApplicationSupportDirectory, inDomains: .UserDomainMask).first!
+#if os(tvOS)
+    internal let deviceDirectorySearchPath = NSSearchPathDirectory.CachesDirectory
+#else
+    internal let deviceDirectorySearchPath = NSSearchPathDirectory.ApplicationSupportDirectory
+#endif
+
+internal let defaultDirectory = NSFileManager.defaultManager().URLsForDirectory(deviceDirectorySearchPath, inDomains: .UserDomainMask).first!
 
 internal let applicationName = (NSBundle.mainBundle().objectForInfoDictionaryKey("CFBundleName") as? String) ?? "CoreData"
 
-internal let defaultSQLiteStoreURL = applicationSupportDirectory.URLByAppendingPathComponent(applicationName, isDirectory: false).URLByAppendingPathExtension("sqlite")
+internal let defaultSQLiteStoreURL = defaultDirectory.URLByAppendingPathComponent(applicationName, isDirectory: false).URLByAppendingPathExtension("sqlite")
 
 
 // MARK: - DataStack
 
 /**
-The `DataStack` encapsulates the data model for the Core Data stack. Each `DataStack` can have multiple data stores, usually specified as a "Configuration" in the model editor. Behind the scenes, the DataStack manages its own `NSPersistentStoreCoordinator`, a root `NSManagedObjectContext` for disk saves, and a shared `NSManagedObjectContext` designed as a read-only model interface for `NSManagedObjects`.
-*/
+ The `DataStack` encapsulates the data model for the Core Data stack. Each `DataStack` can have multiple data stores, usually specified as a "Configuration" in the model editor. Behind the scenes, the DataStack manages its own `NSPersistentStoreCoordinator`, a root `NSManagedObjectContext` for disk saves, and a shared `NSManagedObjectContext` designed as a read-only model interface for `NSManagedObjects`.
+ */
 public final class DataStack {
     
-    // MARK: Public
-    
     /**
-    Initializes a `DataStack` from an `NSManagedObjectModel`.
-    
-    - parameter modelName: the name of the (.xcdatamodeld) model file. If not specified, the application name will be used.
-    - parameter bundle: an optional bundle to load models from. If not specified, the main bundle will be used.
-    - parameter migrationChain: the `MigrationChain` that indicates the sequence of model versions to be used as the order for incremental migration. If not specified, will default to a non-migrating data stack.
-    */
+     Initializes a `DataStack` from an `NSManagedObjectModel`.
+     
+     - parameter modelName: the name of the (.xcdatamodeld) model file. If not specified, the application name will be used.
+     - parameter bundle: an optional bundle to load models from. If not specified, the main bundle will be used.
+     - parameter migrationChain: the `MigrationChain` that indicates the sequence of model versions to be used as the order for progressive migrations. If not specified, will default to a non-migrating data stack.
+     */
     public required init(modelName: String = applicationName, bundle: NSBundle = NSBundle.mainBundle(), migrationChain: MigrationChain = nil) {
         
         CoreStore.assert(
@@ -74,26 +80,53 @@ public final class DataStack {
     }
     
     /**
-    Returns the `DataStack`'s model version. The version string is the same as the name of the version-specific .xcdatamodeld file.
-    */
+     Returns the `DataStack`'s model version. The version string is the same as the name of the version-specific .xcdatamodeld file.
+     */
     public var modelVersion: String {
         
         return self.model.currentModelVersion!
     }
     
     /**
-    Adds an in-memory store to the stack.
+     Returns the entity name-to-class type mapping from the `DataStack`'s model.
+     */
+    public var entityTypesByName: [String: NSManagedObject.Type] {
+        
+        return self.model.entityTypesMapping()
+    }
     
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`.
-    - returns: the `NSPersistentStore` added to the stack.
-    */
+    /**
+     Returns the `NSEntityDescription` for the specified `NSManagedObject` subclass.
+     */
+    public func entityDescriptionForType(type: NSManagedObject.Type) -> NSEntityDescription? {
+        
+        return NSEntityDescription.entityForName(
+            self.model.entityNameForClass(type),
+            inManagedObjectContext: self.mainContext
+        )
+    }
+    
+    /**
+     Returns the `NSManagedObjectID` for the specified object URI if it exists in the persistent store.
+     */
+    public func objectIDForURIRepresentation(url: NSURL) -> NSManagedObjectID? {
+        
+        return self.coordinator.managedObjectIDForURIRepresentation(url)
+    }
+    
+    /**
+     Adds an in-memory store to the stack.
+     
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`.
+     - returns: the `NSPersistentStore` added to the stack.
+     */
     public func addInMemoryStoreAndWait(configuration configuration: String? = nil) throws -> NSPersistentStore {
         
         let coordinator = self.coordinator;
         
         var store: NSPersistentStore?
         var storeError: NSError?
-        coordinator.performBlockAndWait {
+        coordinator.performSynchronously {
             
             do {
                 
@@ -125,17 +158,17 @@ public final class DataStack {
     }
     
     /**
-    Adds to the stack an SQLite store from the given SQLite file name.
-    
-    - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory. A new SQLite file will be created if it does not exist. Note that if you have multiple configurations, you will need to specify a different `fileName` explicitly for each of them.
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`, the "Default" configuration. Note that if you have multiple configurations, you will need to specify a different `fileName` explicitly for each of them.
-    - parameter resetStoreOnModelMismatch: Set to true to delete the store on model mismatch; or set to false to throw exceptions on failure instead. Typically should only be set to true when debugging, or if the persistent store can be recreated easily. If not specified, defaults to false
-    - returns: the `NSPersistentStore` added to the stack.
-    */
+     Adds to the stack an SQLite store from the given SQLite file name.
+     
+     - parameter fileName: the local filename for the SQLite persistent store in the "Application Support" directory (or the "Caches" directory on tvOS). A new SQLite file will be created if it does not exist. Note that if you have multiple configurations, you will need to specify a different `fileName` explicitly for each of them.
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`, the "Default" configuration. Note that if you have multiple configurations, you will need to specify a different `fileName` explicitly for each of them.
+     - parameter resetStoreOnModelMismatch: Set to true to delete the store on model mismatch; or set to false to throw exceptions on failure instead. Typically should only be set to true when debugging, or if the persistent store can be recreated easily. If not specified, defaults to false
+     - returns: the `NSPersistentStore` added to the stack.
+     */
     public func addSQLiteStoreAndWait(fileName fileName: String, configuration: String? = nil, resetStoreOnModelMismatch: Bool = false) throws -> NSPersistentStore {
         
         return try self.addSQLiteStoreAndWait(
-            fileURL: applicationSupportDirectory.URLByAppendingPathComponent(
+            fileURL: defaultDirectory.URLByAppendingPathComponent(
                 fileName,
                 isDirectory: false
             ),
@@ -145,13 +178,13 @@ public final class DataStack {
     }
     
     /**
-    Adds to the stack an SQLite store from the given SQLite file URL.
-    
-    - parameter fileURL: the local file URL for the SQLite persistent store. A new SQLite file will be created if it does not exist. If not specified, defaults to a file URL pointing to a "<Application name>.sqlite" file in the "Application Support" directory. Note that if you have multiple configurations, you will need to specify a different `fileURL` explicitly for each of them.
-    - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`, the "Default" configuration. Note that if you have multiple configurations, you will need to specify a different `fileURL` explicitly for each of them.
-    - parameter resetStoreOnModelMismatch: Set to true to delete the store on model mismatch; or set to false to throw exceptions on failure instead. Typically should only be set to true when debugging, or if the persistent store can be recreated easily. If not specified, defaults to false.
-    - returns: the `NSPersistentStore` added to the stack.
-    */
+     Adds to the stack an SQLite store from the given SQLite file URL.
+     
+     - parameter fileURL: the local file URL for the SQLite persistent store. A new SQLite file will be created if it does not exist. If not specified, defaults to a file URL pointing to a "<Application name>.sqlite" file in the "Application Support" directory (or the "Caches" directory on tvOS). Note that if you have multiple configurations, you will need to specify a different `fileURL` explicitly for each of them.
+     - parameter configuration: an optional configuration name from the model file. If not specified, defaults to `nil`, the "Default" configuration. Note that if you have multiple configurations, you will need to specify a different `fileURL` explicitly for each of them.
+     - parameter resetStoreOnModelMismatch: Set to true to delete the store on model mismatch; or set to false to throw exceptions on failure instead. Typically should only be set to true when debugging, or if the persistent store can be recreated easily. If not specified, defaults to false.
+     - returns: the `NSPersistentStore` added to the stack.
+     */
     public func addSQLiteStoreAndWait(fileURL fileURL: NSURL = defaultSQLiteStoreURL, configuration: String? = nil, resetStoreOnModelMismatch: Bool = false) throws -> NSPersistentStore {
         
         CoreStore.assert(
@@ -162,35 +195,32 @@ public final class DataStack {
         let coordinator = self.coordinator;
         if let store = coordinator.persistentStoreForURL(fileURL) {
             
-            if store.type == NSSQLiteStoreType
-                && store.configurationName == (configuration ?? Into.defaultConfigurationName) {
+            guard store.type == NSSQLiteStoreType
+                && store.configurationName == (configuration ?? Into.defaultConfigurationName) else {
                     
-                    return store
+                    let error = NSError(coreStoreErrorCode: .DifferentPersistentStoreExistsAtURL)
+                    CoreStore.handleError(
+                        error,
+                        "Failed to add SQLite \(typeName(NSPersistentStore)) at \"\(fileURL)\" because a different \(typeName(NSPersistentStore)) at that URL already exists."
+                    )
+                    
+                    throw error
             }
             
-            let error = NSError(coreStoreErrorCode: .DifferentPersistentStoreExistsAtURL)
-            CoreStore.handleError(
-                error,
-                "Failed to add SQLite \(typeName(NSPersistentStore)) at \"\(fileURL)\" because a different \(typeName(NSPersistentStore)) at that URL already exists."
-            )
-            
-            throw error
+            return store
         }
         
         let fileManager = NSFileManager.defaultManager()
-        do {
-            
-            try fileManager.createDirectoryAtURL(
-                fileURL.URLByDeletingLastPathComponent!,
-                withIntermediateDirectories: true,
-                attributes: nil
-            )
-        }
-        catch _ { }
+        _ = try? fileManager.createDirectoryAtURL(
+            fileURL.URLByDeletingLastPathComponent!,
+            withIntermediateDirectories: true,
+            attributes: nil
+        )
         
         var store: NSPersistentStore?
         var storeError: NSError?
-        coordinator.performBlockAndWait {
+        let options = self.optionsForSQLiteStore()
+        coordinator.performSynchronously {
             
             do {
                 
@@ -198,7 +228,7 @@ public final class DataStack {
                     NSSQLiteStoreType,
                     configuration: configuration,
                     URL: fileURL,
-                    options: [NSSQLitePragmasOption: ["journal_mode": "WAL"]]
+                    options: options
                 )
             }
             catch {
@@ -219,7 +249,7 @@ public final class DataStack {
                 fileManager.removeSQLiteStoreAtURL(fileURL)
                 
                 var store: NSPersistentStore?
-                coordinator.performBlockAndWait {
+                coordinator.performSynchronously {
                     
                     do {
                         
@@ -259,17 +289,32 @@ public final class DataStack {
     internal let mainContext: NSManagedObjectContext
     internal let model: NSManagedObjectModel
     internal let migrationChain: MigrationChain
-    internal let childTransactionQueue: GCDQueue = .createSerial("com.corestore.datastack.childtransactionqueue")
+    internal let childTransactionQueue: GCDQueue = .createSerial("com.coreStore.dataStack.childTransactionQueue")
     internal let migrationQueue: NSOperationQueue = {
         
         let migrationQueue = NSOperationQueue()
         migrationQueue.maxConcurrentOperationCount = 1
         migrationQueue.name = "com.coreStore.migrationOperationQueue"
-        migrationQueue.qualityOfService = .Utility
-        migrationQueue.underlyingQueue = dispatch_queue_create("com.coreStore.migrationQueue", DISPATCH_QUEUE_SERIAL)
+        #if USE_FRAMEWORKS
+            
+            migrationQueue.qualityOfService = .Utility
+            migrationQueue.underlyingQueue = dispatch_queue_create("com.coreStore.migrationQueue", DISPATCH_QUEUE_SERIAL)
+        #else
+            
+            if #available(iOS 8.0, *) {
+                
+                migrationQueue.qualityOfService = .Utility
+                migrationQueue.underlyingQueue = dispatch_queue_create("com.coreStore.migrationQueue", DISPATCH_QUEUE_SERIAL)
+            }
+        #endif
         return migrationQueue
     }()
     
+    internal func optionsForSQLiteStore() -> [String: AnyObject] {
+        
+        return [NSSQLitePragmasOption: ["journal_mode": "WAL"]]
+    }
+    
     internal func entityNameForEntityClass(entityClass: AnyClass) -> String? {
         
         return self.model.entityNameForClass(entityClass)
@@ -330,11 +375,17 @@ public final class DataStack {
             self.configurationStoreMapping[configurationName] = persistentStore
             for entityDescription in (self.coordinator.managedObjectModel.entitiesForConfiguration(configurationName) ?? []) {
                 
-                if self.entityConfigurationsMapping[entityDescription.managedObjectClassName] == nil {
+                let managedObjectClassName = entityDescription.managedObjectClassName
+                CoreStore.assert(
+                    NSClassFromString(managedObjectClassName) != nil,
+                    "The class \(typeName(managedObjectClassName)) for the entity \(typeName(entityDescription.name)) does not exist. Check if the subclass type and module name are properly configured."
+                )
+                
+                if self.entityConfigurationsMapping[managedObjectClassName] == nil {
                     
-                    self.entityConfigurationsMapping[entityDescription.managedObjectClassName] = []
+                    self.entityConfigurationsMapping[managedObjectClassName] = []
                 }
-                self.entityConfigurationsMapping[entityDescription.managedObjectClassName]?.insert(configurationName)
+                self.entityConfigurationsMapping[managedObjectClassName]?.insert(configurationName)
             }
         }
     }
@@ -348,13 +399,16 @@ public final class DataStack {
     
     deinit {
         
-        for store in self.coordinator.persistentStores {
+        let coordinator = self.coordinator
+        coordinator.performAsynchronously {
             
-            do {
+            withExtendedLifetime(coordinator) { coordinator in
                 
-                try self.coordinator.removePersistentStore(store)
+                coordinator.persistentStores.forEach {
+                    
+                    _ = try? coordinator.removePersistentStore($0)
+                }
             }
-            catch _ { }
         }
     }
 }

CoreStore/Setting Up/PersistentStoreResult.swift

@@ -2,7 +2,7 @@
 //  PersistentStoreResult.swift
 //  CoreStore
 //
-//  Copyright (c) 2014 John Rommel Estropia
+//  Copyright © 2014 John Rommel Estropia
 //
 //  Permission is hereby granted, free of charge, to any person obtaining a copy
 //  of this software and associated documentation files (the "Software"), to deal
@@ -30,42 +30,40 @@ import CoreData
 // MARK: - PersistentStoreResult
 
 /**
-The `PersistentStoreResult` indicates the result of an asynchronous initialization of a persistent store.
-The `PersistentStoreResult` can be treated as a boolean:
-
-    try! CoreStore.addSQLiteStore(completion: { (result: PersistentStoreResult) -> Void in
-        if result {
-            // succeeded
-        }
-        else {
-            // failed
-        }
-    })
-
-or as an `enum`, where the resulting associated object can also be inspected:
-
-    try! CoreStore.addSQLiteStore(completion: { (result: PersistentStoreResult) -> Void in
-        switch result {
-        case .Success(let persistentStore):
-            // persistentStore is the related NSPersistentStore instance
-        case .Failure(let error):
-            // error is the NSError instance for the failure
-        }
-    })
-```
-*/
+ The `PersistentStoreResult` indicates the result of an asynchronous initialization of a persistent store.
+ The `PersistentStoreResult` can be treated as a boolean:
+ ```
+ try! CoreStore.addSQLiteStore(completion: { (result: PersistentStoreResult) -> Void in
+     if result {
+        // succeeded
+     }
+     else {
+        // failed
+     }
+ })
+ ```
+ or as an `enum`, where the resulting associated object can also be inspected:
+ ```
+ try! CoreStore.addSQLiteStore(completion: { (result: PersistentStoreResult) -> Void in
+     switch result {
+     case .Success(let persistentStore):
+        // persistentStore is the related NSPersistentStore instance
+     case .Failure(let error):
+        // error is the NSError instance for the failure
+     }
+ })
+ ```
+ */
 public enum PersistentStoreResult {
     
-    // MARK: Public
-    
     /**
-    `PersistentStoreResult.Success` indicates that the persistent store process succeeded. The associated object for this `enum` value is the related `NSPersistentStore` instance.
-    */
+     `PersistentStoreResult.Success` indicates that the persistent store process succeeded. The associated object for this `enum` value is the related `NSPersistentStore` instance.
+     */
     case Success(NSPersistentStore)
     
     /**
-    `PersistentStoreResult.Failure` indicates that the persistent store process failed. The associated object for this value is the related `NSError` instance.
-    */
+     `PersistentStoreResult.Failure` indicates that the persistent store process failed. The associated object for this value is the related `NSError` instance.
+     */
     case Failure(NSError)
     
     
@@ -88,9 +86,7 @@ public enum PersistentStoreResult {
     
     internal init(_ errorCode: CoreStoreErrorCode, userInfo: [NSObject: AnyObject]?) {
         
-        self.init(NSError(
-            coreStoreErrorCode: errorCode,
-            userInfo: userInfo))
+        self.init(NSError(coreStoreErrorCode: errorCode, userInfo: userInfo))
     }
 }
 
@@ -99,8 +95,6 @@ public enum PersistentStoreResult {
 
 extension PersistentStoreResult: BooleanType {
     
-    // MARK: Public
-    
     public var boolValue: Bool {
         
         switch self {

CoreStoreDemo/CoreStoreDemo.xcodeproj/project.pbxproj

@@ -35,11 +35,11 @@
 		B569651A1B30888A0075EE4A /* FetchingResultsViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = B56965191B30888A0075EE4A /* FetchingResultsViewController.swift */; };
 		B569651C1B30889A0075EE4A /* QueryingResultsViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = B569651B1B30889A0075EE4A /* QueryingResultsViewController.swift */; };
 		B56965291B3582D30075EE4A /* MigrationDemo.xcdatamodeld in Sources */ = {isa = PBXBuildFile; fileRef = B56965271B3582D30075EE4A /* MigrationDemo.xcdatamodeld */; };
-		B583A9201AF5F542001F76AF /* CoreStore.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = B583A91B1AF5F4F4001F76AF /* CoreStore.framework */; };
-		B583A9211AF5F542001F76AF /* CoreStore.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = B583A91B1AF5F4F4001F76AF /* CoreStore.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
-		B5D9C9191B20AB1900E64F0E /* GCDKit.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = B5D9C9181B20AB1900E64F0E /* GCDKit.framework */; };
-		B5D9C91A1B20AB1900E64F0E /* GCDKit.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = B5D9C9181B20AB1900E64F0E /* GCDKit.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 		B5E599321B5240F50084BD5F /* OrganismTableViewCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5E599311B5240F50084BD5F /* OrganismTableViewCell.swift */; };
+		B5E89ACD1C52929C003B04A9 /* GCDKit.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = B5BDC9241C202429008147CD /* GCDKit.framework */; };
+		B5E89ACE1C52929C003B04A9 /* GCDKit.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = B5BDC9241C202429008147CD /* GCDKit.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
+		B5E89AD01C5292A2003B04A9 /* CoreStore.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = B5BDC9211C202429008147CD /* CoreStore.framework */; };
+		B5E89AD11C5292A2003B04A9 /* CoreStore.framework in Embed Frameworks */ = {isa = PBXBuildFile; fileRef = B5BDC9211C202429008147CD /* CoreStore.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 		B5EE25851B36E23C0000406B /* OrganismV1.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5EE25841B36E23C0000406B /* OrganismV1.swift */; };
 		B5EE25871B36E2520000406B /* OrganismV2.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5EE25861B36E2520000406B /* OrganismV2.swift */; };
 		B5EE258C1B36E40D0000406B /* MigrationsDemoViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5EE258B1B36E40D0000406B /* MigrationsDemoViewController.swift */; };
@@ -47,46 +47,15 @@
 		B5EE259E1B3EC1B20000406B /* OrganismProtocol.swift in Sources */ = {isa = PBXBuildFile; fileRef = B5EE259D1B3EC1B20000406B /* OrganismProtocol.swift */; };
 /* End PBXBuildFile section */
 
-/* Begin PBXContainerItemProxy section */
-		B583A91A1AF5F4F4001F76AF /* PBXContainerItemProxy */ = {
-			isa = PBXContainerItemProxy;
-			containerPortal = B583A9141AF5F4F3001F76AF /* CoreStore.xcodeproj */;
-			proxyType = 2;
-			remoteGlobalIDString = 2F03A53019C5C6DA005002A5;
-			remoteInfo = CoreStore;
-		};
-		B583A91C1AF5F4F4001F76AF /* PBXContainerItemProxy */ = {
-			isa = PBXContainerItemProxy;
-			containerPortal = B583A9141AF5F4F3001F76AF /* CoreStore.xcodeproj */;
-			proxyType = 2;
-			remoteGlobalIDString = 2F03A53B19C5C6DA005002A5;
-			remoteInfo = CoreStoreTests;
-		};
-		B583A91E1AF5F512001F76AF /* PBXContainerItemProxy */ = {
-			isa = PBXContainerItemProxy;
-			containerPortal = B583A9141AF5F4F3001F76AF /* CoreStore.xcodeproj */;
-			proxyType = 1;
-			remoteGlobalIDString = 2F03A52F19C5C6DA005002A5;
-			remoteInfo = CoreStore;
-		};
-		B583A9221AF5F542001F76AF /* PBXContainerItemProxy */ = {
-			isa = PBXContainerItemProxy;
-			containerPortal = B583A9141AF5F4F3001F76AF /* CoreStore.xcodeproj */;
-			proxyType = 1;
-			remoteGlobalIDString = 2F03A52F19C5C6DA005002A5;
-			remoteInfo = CoreStore;
-		};
-/* End PBXContainerItemProxy section */
-
 /* Begin PBXCopyFilesBuildPhase section */
-		B583A9241AF5F542001F76AF /* Embed Frameworks */ = {
+		B5E89ACF1C52929C003B04A9 /* Embed Frameworks */ = {
 			isa = PBXCopyFilesBuildPhase;
 			buildActionMask = 2147483647;
 			dstPath = "";
 			dstSubfolderSpec = 10;
 			files = (
-				B5D9C91A1B20AB1900E64F0E /* GCDKit.framework in Embed Frameworks */,
-				B583A9211AF5F542001F76AF /* CoreStore.framework in Embed Frameworks */,
+				B5E89ACE1C52929C003B04A9 /* GCDKit.framework in Embed Frameworks */,
+				B5E89AD11C5292A2003B04A9 /* CoreStore.framework in Embed Frameworks */,
 			);
 			name = "Embed Frameworks";
 			runOnlyForDeploymentPostprocessing = 0;
@@ -124,8 +93,8 @@
 		B56965191B30888A0075EE4A /* FetchingResultsViewController.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = FetchingResultsViewController.swift; sourceTree = "<group>"; };
 		B569651B1B30889A0075EE4A /* QueryingResultsViewController.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = QueryingResultsViewController.swift; sourceTree = "<group>"; };
 		B56965281B3582D30075EE4A /* MigrationDemo.xcdatamodel */ = {isa = PBXFileReference; lastKnownFileType = wrapper.xcdatamodel; path = MigrationDemo.xcdatamodel; sourceTree = "<group>"; };
-		B583A9141AF5F4F3001F76AF /* CoreStore.xcodeproj */ = {isa = PBXFileReference; lastKnownFileType = "wrapper.pb-project"; name = CoreStore.xcodeproj; path = ../CoreStore.xcodeproj; sourceTree = "<group>"; };
-		B5D9C9181B20AB1900E64F0E /* GCDKit.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; path = GCDKit.framework; sourceTree = BUILT_PRODUCTS_DIR; };
+		B5BDC9211C202429008147CD /* CoreStore.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; path = CoreStore.framework; sourceTree = BUILT_PRODUCTS_DIR; };
+		B5BDC9241C202429008147CD /* GCDKit.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; path = GCDKit.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		B5E599311B5240F50084BD5F /* OrganismTableViewCell.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; name = OrganismTableViewCell.swift; path = "CoreStoreDemo/MIgrations Demo/OrganismTableViewCell.swift"; sourceTree = SOURCE_ROOT; };
 		B5EE25801B36E1B00000406B /* MigrationDemoV2.xcdatamodel */ = {isa = PBXFileReference; lastKnownFileType = wrapper.xcdatamodel; path = MigrationDemoV2.xcdatamodel; sourceTree = "<group>"; };
 		B5EE25841B36E23C0000406B /* OrganismV1.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = OrganismV1.swift; sourceTree = "<group>"; };
@@ -141,10 +110,10 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				B5E89ACD1C52929C003B04A9 /* GCDKit.framework in Frameworks */,
+				B5E89AD01C5292A2003B04A9 /* CoreStore.framework in Frameworks */,
 				B52977E11B120F8A003D50A5 /* CoreLocation.framework in Frameworks */,
 				B52977DF1B120F83003D50A5 /* MapKit.framework in Frameworks */,
-				B5D9C9191B20AB1900E64F0E /* GCDKit.framework in Frameworks */,
-				B583A9201AF5F542001F76AF /* CoreStore.framework in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
@@ -175,9 +144,9 @@
 		B52977E21B120F90003D50A5 /* Frameworks */ = {
 			isa = PBXGroup;
 			children = (
-				B583A9141AF5F4F3001F76AF /* CoreStore.xcodeproj */,
-				B5D9C9181B20AB1900E64F0E /* GCDKit.framework */,
 				B52977E01B120F8A003D50A5 /* CoreLocation.framework */,
+				B5BDC9211C202429008147CD /* CoreStore.framework */,
+				B5BDC9241C202429008147CD /* GCDKit.framework */,
 				B52977DE1B120F83003D50A5 /* MapKit.framework */,
 			);
 			name = Frameworks;
@@ -275,15 +244,6 @@
 			path = "Migrations Demo";
 			sourceTree = "<group>";
 		};
-		B583A9151AF5F4F3001F76AF /* Products */ = {
-			isa = PBXGroup;
-			children = (
-				B583A91B1AF5F4F4001F76AF /* CoreStore.framework */,
-				B583A91D1AF5F4F4001F76AF /* CoreStoreTests.xctest */,
-			);
-			name = Products;
-			sourceTree = "<group>";
-		};
 /* End PBXGroup section */
 
 /* Begin PBXNativeTarget section */
@@ -294,13 +254,11 @@
 				B54AAD451AF4D26E00848AE0 /* Sources */,
 				B54AAD461AF4D26E00848AE0 /* Frameworks */,
 				B54AAD471AF4D26E00848AE0 /* Resources */,
-				B583A9241AF5F542001F76AF /* Embed Frameworks */,
+				B5E89ACF1C52929C003B04A9 /* Embed Frameworks */,
 			);
 			buildRules = (
 			);
 			dependencies = (
-				B583A91F1AF5F512001F76AF /* PBXTargetDependency */,
-				B583A9231AF5F542001F76AF /* PBXTargetDependency */,
 			);
 			name = CoreStoreDemo;
 			productName = CoreStoreDemo;
@@ -333,12 +291,6 @@
 			mainGroup = B54AAD401AF4D26E00848AE0;
 			productRefGroup = B54AAD4A1AF4D26E00848AE0 /* Products */;
 			projectDirPath = "";
-			projectReferences = (
-				{
-					ProductGroup = B583A9151AF5F4F3001F76AF /* Products */;
-					ProjectRef = B583A9141AF5F4F3001F76AF /* CoreStore.xcodeproj */;
-				},
-			);
 			projectRoot = "";
 			targets = (
 				B54AAD481AF4D26E00848AE0 /* CoreStoreDemo */,
@@ -346,23 +298,6 @@
 		};
 /* End PBXProject section */
 
-/* Begin PBXReferenceProxy section */
-		B583A91B1AF5F4F4001F76AF /* CoreStore.framework */ = {
-			isa = PBXReferenceProxy;
-			fileType = wrapper.framework;
-			path = CoreStore.framework;
-			remoteRef = B583A91A1AF5F4F4001F76AF /* PBXContainerItemProxy */;
-			sourceTree = BUILT_PRODUCTS_DIR;
-		};
-		B583A91D1AF5F4F4001F76AF /* CoreStoreTests.xctest */ = {
-			isa = PBXReferenceProxy;
-			fileType = wrapper.cfbundle;
-			path = CoreStoreTests.xctest;
-			remoteRef = B583A91C1AF5F4F4001F76AF /* PBXContainerItemProxy */;
-			sourceTree = BUILT_PRODUCTS_DIR;
-		};
-/* End PBXReferenceProxy section */
-
 /* Begin PBXResourcesBuildPhase section */
 		B54AAD471AF4D26E00848AE0 /* Resources */ = {
 			isa = PBXResourcesBuildPhase;
@@ -415,19 +350,6 @@
 		};
 /* End PBXSourcesBuildPhase section */
 
-/* Begin PBXTargetDependency section */
-		B583A91F1AF5F512001F76AF /* PBXTargetDependency */ = {
-			isa = PBXTargetDependency;
-			name = CoreStore;
-			targetProxy = B583A91E1AF5F512001F76AF /* PBXContainerItemProxy */;
-		};
-		B583A9231AF5F542001F76AF /* PBXTargetDependency */ = {
-			isa = PBXTargetDependency;
-			name = CoreStore;
-			targetProxy = B583A9221AF5F542001F76AF /* PBXContainerItemProxy */;
-		};
-/* End PBXTargetDependency section */
-
 /* Begin PBXVariantGroup section */
 		B54AAD571AF4D26E00848AE0 /* Main.storyboard */ = {
 			isa = PBXVariantGroup;

CoreStoreDemo/CoreStoreDemo/AppDelegate.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/05/02.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import UIKit

CoreStoreDemo/CoreStoreDemo/Fetching and Querying Demo/FetchingAndQueryingDemoViewController.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/06/12.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import UIKit
@@ -37,7 +37,7 @@ private struct Static {
                 cachedTimeZone.daylightSavingTimeOffset = rawTimeZone.daylightSavingTimeOffset
             }
             
-            transaction.commit()
+            transaction.commitAndWait()
         }
         
         return dataStack
@@ -99,10 +99,10 @@ class FetchingAndQueryingDemoViewController: UIViewController, UITableViewDataSo
     func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
         switch self.segmentedControl?.selectedSegmentIndex {
             
-        case .Some(Section.Fetching.rawValue):
+        case Section.Fetching.rawValue?:
             return self.fetchingItems.count
             
-        case .Some(Section.Querying.rawValue):
+        case Section.Querying.rawValue?:
             return self.queryingItems.count
             
         default:
@@ -116,10 +116,10 @@ class FetchingAndQueryingDemoViewController: UIViewController, UITableViewDataSo
         
         switch self.segmentedControl?.selectedSegmentIndex {
             
-        case .Some(Section.Fetching.rawValue):
+        case Section.Fetching.rawValue?:
             cell.textLabel?.text = self.fetchingItems[indexPath.row].title
             
-        case .Some(Section.Querying.rawValue):
+        case Section.Querying.rawValue?:
             cell.textLabel?.text = self.queryingItems[indexPath.row].title
             
         default:
@@ -138,10 +138,10 @@ class FetchingAndQueryingDemoViewController: UIViewController, UITableViewDataSo
         
         switch self.segmentedControl?.selectedSegmentIndex {
             
-        case .Some(Section.Fetching.rawValue):
+        case Section.Fetching.rawValue?:
             self.performSegueWithIdentifier("FetchingResultsViewController", sender: indexPath)
             
-        case .Some(Section.Querying.rawValue):
+        case Section.Querying.rawValue?:
             self.performSegueWithIdentifier("QueryingResultsViewController", sender: indexPath)
             
         default:

CoreStoreDemo/CoreStoreDemo/Fetching and Querying Demo/FetchingResultsViewController.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/06/17.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import UIKit

CoreStoreDemo/CoreStoreDemo/Fetching and Querying Demo/QueryingResultsViewController.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/06/17.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import UIKit
@@ -16,19 +16,19 @@ class QueryingResultsViewController: UITableViewController {
         
         switch value {
             
-        case .Some(let array as [AnyObject]):
+        case (let array as [AnyObject])?:
             self.values = array.map { (item: AnyObject) -> (title: String, detail: String) in
                 (
                     title: item.description,
-                    detail: _stdlib_getDemangledTypeName(item)
+                    detail: String(reflecting: item.dynamicType)
                 )
             }
             
-        case .Some(let item):
+        case let item?:
             self.values = [
                 (
                     title: item.description,
-                    detail: _stdlib_getDemangledTypeName(item)
+                    detail: String(reflecting: item.dynamicType)
                 )
             ]
             

CoreStoreDemo/CoreStoreDemo/Fetching and Querying Demo/TimeZone.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/06/15.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import Foundation

CoreStoreDemo/CoreStoreDemo/List and Object Observers Demo/ListObserverDemoViewController.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/05/02.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import UIKit
@@ -12,6 +12,41 @@ import CoreStore
 
 private struct Static {
     
+    enum Filter: String {
+        
+        case All = "All Colors"
+        case Light = "Light Colors"
+        case Dark = "Dark Colors"
+        
+        func next() -> Filter {
+            
+            switch self {
+                
+            case All: return .Light
+            case Light: return .Dark
+            case Dark: return .All
+            }
+        }
+        
+        func whereClause() -> Where {
+            
+            switch self {
+                
+            case .All: return Where(true)
+            case .Light: return Where("brightness >= 0.9")
+            case .Dark: return Where("brightness <= 0.4")
+            }
+        }
+    }
+    
+    static var filter = Filter.All {
+        
+        didSet {
+            
+            self.palettes.refetch(self.filter.whereClause())
+        }
+    }
+    
     static let palettes: ListMonitor<Palette> = {
         
         try! CoreStore.addSQLiteStoreAndWait(
@@ -47,21 +82,35 @@ class ListObserverDemoViewController: UITableViewController, ListSectionObserver
         
         super.viewDidLoad()
         
-        self.navigationItem.leftBarButtonItems = [
+        let navigationItem = self.navigationItem
+        navigationItem.leftBarButtonItems = [
             self.editButtonItem(),
             UIBarButtonItem(
                 barButtonSystemItem: .Trash,
                 target: self,
-                action: "resetBarButtonItemTouched:"
+                action: #selector(self.resetBarButtonItemTouched(_:))
             )
         ]
-        self.navigationItem.rightBarButtonItem = UIBarButtonItem(
-            barButtonSystemItem: .Add,
+        
+        let filterBarButton = UIBarButtonItem(
+            title: Static.filter.rawValue,
+            style: .Plain,
             target: self,
-            action: "addBarButtonItemTouched:"
+            action: #selector(self.filterBarButtonItemTouched(_:))
         )
+        navigationItem.rightBarButtonItems = [
+            UIBarButtonItem(
+                barButtonSystemItem: .Add,
+                target: self,
+                action: #selector(self.addBarButtonItemTouched(_:))
+            ),
+            filterBarButton
+        ]
+        self.filterBarButton = filterBarButton
         
         Static.palettes.addObserver(self)
+        
+        self.setTableEnabled(!Static.palettes.isPendingRefetch)
     }
     
     override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
@@ -70,7 +119,7 @@ class ListObserverDemoViewController: UITableViewController, ListSectionObserver
         
         switch (segue.identifier, segue.destinationViewController, sender) {
             
-        case (.Some("ObjectObserverDemoViewController"), let destinationViewController as ObjectObserverDemoViewController, let palette as Palette):
+        case ("ObjectObserverDemoViewController"?, let destinationViewController as ObjectObserverDemoViewController, let palette as Palette):
             destinationViewController.palette = palette
             
         default:
@@ -150,6 +199,18 @@ class ListObserverDemoViewController: UITableViewController, ListSectionObserver
         self.tableView.endUpdates()
     }
     
+    func listMonitorWillRefetch(monitor: ListMonitor<Palette>) {
+        
+        self.setTableEnabled(false)
+    }
+    
+    func listMonitorDidRefetch(monitor: ListMonitor<Palette>) {
+        
+        self.filterBarButton?.title = Static.filter.rawValue
+        self.tableView.reloadData()
+        self.setTableEnabled(true)
+    }
+    
     
     // MARK: ListObjectObserver
     
@@ -195,6 +256,8 @@ class ListObserverDemoViewController: UITableViewController, ListSectionObserver
     
     // MARK: Private
     
+    private var filterBarButton: UIBarButtonItem?
+    
     @IBAction private dynamic func resetBarButtonItemTouched(sender: AnyObject?) {
         
         CoreStore.beginAsynchronous { (transaction) -> Void in
@@ -204,6 +267,11 @@ class ListObserverDemoViewController: UITableViewController, ListSectionObserver
         }
     }
     
+    @IBAction private dynamic func filterBarButtonItemTouched(sender: AnyObject?) {
+        
+        Static.filter = Static.filter.next()
+    }
+    
     @IBAction private dynamic func addBarButtonItemTouched(sender: AnyObject?) {
         
         CoreStore.beginAsynchronous { (transaction) -> Void in
@@ -214,5 +282,23 @@ class ListObserverDemoViewController: UITableViewController, ListSectionObserver
             transaction.commit()
         }
     }
+    
+    private func setTableEnabled(enabled: Bool) {
+        
+        UIView.animateWithDuration(
+            0.2,
+            delay: 0,
+            options: .BeginFromCurrentState,
+            animations: { () -> Void in
+                
+                if let tableView = self.tableView {
+                    
+                    tableView.alpha = enabled ? 1.0 : 0.5
+                    tableView.userInteractionEnabled = enabled
+                }
+            },
+            completion: nil
+        )
+    }
 }
 

CoreStoreDemo/CoreStoreDemo/List and Object Observers Demo/ObjectObserverDemoViewController.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/05/06.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import UIKit
@@ -22,6 +22,11 @@ class ObjectObserverDemoViewController: UIViewController, ObjectObserver {
         }
         set {
             
+            guard self.monitor?.object != newValue else {
+                
+                return
+            }
+            
             if let palette = newValue {
                 
                 self.monitor = CoreStore.monitorObject(palette)
@@ -56,7 +61,7 @@ class ObjectObserverDemoViewController: UIViewController, ObjectObserver {
                 let palette = transaction.create(Into(Palette))
                 palette.setInitialValues()
                 
-                transaction.commit()
+                transaction.commitAndWait()
             }
             
             let palette = CoreStore.fetchOne(From(Palette), OrderBy(.Ascending("hue")))!
@@ -80,11 +85,6 @@ class ObjectObserverDemoViewController: UIViewController, ObjectObserver {
     
     // MARK: ObjectObserver
     
-    func objectMonitor(monitor: ObjectMonitor<Palette>, willUpdateObject object: Palette) {
-        
-        // none
-    }
-    
     func objectMonitor(monitor: ObjectMonitor<Palette>, didUpdateObject object: Palette, changedPersistentKeys: Set<KeyPath>) {
         
         self.reloadPaletteInfo(object, changedKeys: changedPersistentKeys)

CoreStoreDemo/CoreStoreDemo/List and Object Observers Demo/ObserversViewController.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/05/24.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import UIKit

CoreStoreDemo/CoreStoreDemo/List and Object Observers Demo/Palette.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/05/05.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import Foundation

CoreStoreDemo/CoreStoreDemo/List and Object Observers Demo/PaletteTableViewCell.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/05/05.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import UIKit

CoreStoreDemo/CoreStoreDemo/Loggers Demo/CustomLoggerViewController.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/06/05.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import UIKit
@@ -62,7 +62,7 @@ class CustomLoggerViewController: UIViewController, CoreStoreLogger {
             case .Warning: levelString = "Warning"
             case .Fatal: levelString = "Fatal"
             }
-            self?.textView?.insertText("\(fileName.stringValue.lastPathComponent):\(lineNumber) \(functionName)\n  ↪︎ [Log:\(levelString)] \(message)\n\n")
+            self?.textView?.insertText("\((fileName.stringValue as NSString).lastPathComponent):\(lineNumber) \(functionName)\n  ↪︎ [Log:\(levelString)] \(message)\n\n")
         }
     }
     
@@ -70,7 +70,7 @@ class CustomLoggerViewController: UIViewController, CoreStoreLogger {
         
         GCDQueue.Main.async { [weak self] in
             
-            self?.textView?.insertText("\(fileName.stringValue.lastPathComponent):\(lineNumber) \(functionName)\n  ↪︎ [Error] \(message): \(error)\n\n")
+            self?.textView?.insertText("\((fileName.stringValue as NSString).lastPathComponent):\(lineNumber) \(functionName)\n  ↪︎ [Error] \(message): \(error)\n\n")
         }
     }
     
@@ -83,13 +83,13 @@ class CustomLoggerViewController: UIViewController, CoreStoreLogger {
         
         GCDQueue.Main.async { [weak self] in
             
-            self?.textView?.insertText("\(fileName.stringValue.lastPathComponent):\(lineNumber) \(functionName)\n  ↪︎ [Assert] \(message)\n\n")
+            self?.textView?.insertText("\((fileName.stringValue as NSString).lastPathComponent):\(lineNumber) \(functionName)\n  ↪︎ [Assert] \(message)\n\n")
         }
     }
     
     @noreturn func fatalError(message: String, fileName: StaticString, lineNumber: Int, functionName: StaticString) {
         
-        Swift.fatalError("\(fileName.stringValue.lastPathComponent):\(lineNumber) \(functionName)\n  ↪︎ [Abort] \(message)")
+        Swift.fatalError("\((fileName.stringValue as NSString).lastPathComponent):\(lineNumber) \(functionName)\n  ↪︎ [Abort] \(message)")
     }
     
     
@@ -102,20 +102,20 @@ class CustomLoggerViewController: UIViewController, CoreStoreLogger {
         
         switch self.segmentedControl?.selectedSegmentIndex {
             
-        case .Some(0):
+        case 0?:
             self.dataStack.beginAsynchronous { (transaction) -> Void in
                 
                 transaction.create(Into(Palette))
             }
             
-        case .Some(1):
+        case 1?:
             do {
                 
                 try self.dataStack.addSQLiteStoreAndWait(fileName: "emptyStore.sqlite", configuration: "invalidStore")
             }
             catch _ { }
             
-        case .Some(2):
+        case 2?:
             self.dataStack.beginAsynchronous { (transaction) -> Void in
                 
                 transaction.commit()

CoreStoreDemo/CoreStoreDemo/MIgrations Demo/MigrationsDemoViewController.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/06/21.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import UIKit
@@ -37,6 +37,15 @@ class MigrationsDemoViewController: UIViewController {
         
         super.viewDidAppear(animated)
         
+        let alert = UIAlertController(
+            title: "Migrations Demo",
+            message: "This demo shows how to run progressive migrations and how to support multiple model versions in a single project.\n\nThe persistent store contains 10000 organisms, which gain/lose properties when the migration evolves/devolves them.\n\nYou can use the \"mutate\" button to change an organism's properties then migrate to a different model to see how its value gets affected.",
+            preferredStyle: .Alert
+        )
+        alert.addAction(UIAlertAction(title: "OK", style: .Cancel, handler: nil))
+        self.presentViewController(alert, animated: true, completion: nil)
+        
+        
         let modelMetadata = withExtendedLifetime(DataStack(modelName: "MigrationDemo")) {
             (dataStack: DataStack) -> ModelMetadata in
             
@@ -153,36 +162,46 @@ class MigrationsDemoViewController: UIViewController {
             fileName: "MigrationDemo.sqlite",
             completion: { [weak self] (result) -> Void in
                 
-                guard let strongSelf = self else {
+                guard let `self` = self else {
                     
                     return
                 }
                 
                 guard case .Success = result else {
                     
-                    strongSelf.setEnabled(true)
+                    self.setEnabled(true)
                     return
                 }
                 
-                strongSelf.setDataStack(dataStack, model: model, scrollToSelection: true)
+                self.setDataStack(dataStack, model: model, scrollToSelection: true)
                 
-                let count = dataStack.queryValue(From(model.entityType), Select<Int>(.Count("dna")))
+                let count = dataStack.queryValue(
+                    From(model.entityType),
+                    Select<Int>(.Count("dna"))
+                )
                 if count > 0 {
                     
-                    strongSelf.setEnabled(true)
+                    self.setEnabled(true)
                 }
                 else {
                     
-                    dataStack.beginAsynchronous { (transaction) -> Void in
+                    for i: Int64 in 0 ..< 20 {
                         
-                        for i: Int64 in 1 ..< 10000 {
+                        dataStack.beginAsynchronous { (transaction) -> Void in
                             
-                            let organism = transaction.create(Into(model.entityType)) as! OrganismProtocol
-                            organism.dna = i
-                            organism.mutate()
+                            for j: Int64 in 0 ..< 500 {
+                                
+                                let organism = transaction.create(Into(model.entityType)) as! OrganismProtocol
+                                organism.dna = (i * 500) + j + 1
+                                organism.mutate()
+                            }
+                            
+                            transaction.commit()
                         }
+                    }
+                    dataStack.beginAsynchronous { [weak self] (transaction) -> Void in
                         
-                        transaction.commit { result -> Void in
+                        transaction.commit { _ in
                             
                             self?.setEnabled(true)
                         }
@@ -258,7 +277,7 @@ class MigrationsDemoViewController: UIViewController {
         
         self.progressView?.setProgress(Float(progress.fractionCompleted), animated: true)
         self.titleLabel?.text = "Migrating: \(progress.localizedDescription)"
-        self.organismLabel?.text = "Incremental step \(progress.localizedAdditionalDescription)"
+        self.organismLabel?.text = "Progressive step \(progress.localizedAdditionalDescription)"
     }
     
     private func updateDisplay(reloadData reloadData: Bool, scrollToSelection: Bool, animated: Bool) {
@@ -276,7 +295,7 @@ class MigrationsDemoViewController: UIViewController {
         }
         
         self.titleLabel?.text = organismType
-        self.organismLabel?.text = "\n".join(lines)
+        self.organismLabel?.text = lines.joinWithSeparator("\n")
         self.progressView?.progress = 0
         
         self.headerContainer?.setNeedsLayout()

CoreStoreDemo/CoreStoreDemo/MIgrations Demo/OrganismProtocol.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/06/27.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import Foundation

CoreStoreDemo/CoreStoreDemo/MIgrations Demo/OrganismV1.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/06/21.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import Foundation

CoreStoreDemo/CoreStoreDemo/MIgrations Demo/OrganismV2.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/06/21.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import Foundation

CoreStoreDemo/CoreStoreDemo/MIgrations Demo/OrganismV2ToV3MigrationPolicy.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/06/27.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import CoreData

CoreStoreDemo/CoreStoreDemo/MIgrations Demo/OrganismV3.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/06/27.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import Foundation

CoreStoreDemo/CoreStoreDemo/Stack Setup Demo/FemaleAccount.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/06/06.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import Foundation

CoreStoreDemo/CoreStoreDemo/Stack Setup Demo/MaleAccount.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/06/06.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import Foundation

CoreStoreDemo/CoreStoreDemo/Stack Setup Demo/StackSetupDemoViewController.swift

@@ -3,7 +3,7 @@
 //  CoreStoreDemo
 //
 //  Created by John Rommel Estropia on 2015/05/24.
-//  Copyright (c) 2015 John Rommel Estropia. All rights reserved.
+//  Copyright © 2015 John Rommel Estropia. All rights reserved.
 //
 
 import UIKit
@@ -43,7 +43,7 @@ private struct Static {
             account2.name = "Jane Doe HCD"
             account2.friends = 314
             
-            transaction.commit()
+            transaction.commitAndWait()
         }
         
         return dataStack
@@ -77,7 +77,7 @@ private struct Static {
             account2.name = "#janedoe_hcd"
             account2.friends = 100
             
-            transaction.commit()
+            transaction.commitAndWait()
         }
         
         return dataStack