workaround an NSFetchedResultsController bug in Xcode 7 targeted on iOS 8 devices where errant index paths cause crashes

2026-01-15 05:33:31 +01:00 · 2015-09-10 16:57:35 +09:00
parent 4c6bc4f494
commit 5461bb0736
4 changed files with 200 additions and 126 deletions
--- a/CoreStore.xcodeproj/project.pbxproj
+++ b/CoreStore.xcodeproj/project.pbxproj
@@ -13,6 +13,7 @@
 		2F291E2719C6D3CF007AF63F /* CoreStore.swift in Sources */ = {isa = PBXBuildFile; fileRef = 2F291E2619C6D3CF007AF63F /* CoreStore.swift */; };
 		B504D0D61B02362500B2BBB1 /* CoreStore+Setup.swift in Sources */ = {isa = PBXBuildFile; fileRef = B504D0D51B02362500B2BBB1 /* CoreStore+Setup.swift */; };
 		B51BE06A1B47FC4B0069F532 /* NSManagedObjectModel+Setup.swift in Sources */ = {isa = PBXBuildFile; fileRef = B51BE0691B47FC4B0069F532 /* NSManagedObjectModel+Setup.swift */; };
+		B54A6A551BA15F2A007870FD /* FetchedResultsControllerDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = B54A6A541BA15F2A007870FD /* FetchedResultsControllerDelegate.swift */; settings = {ASSET_TAGS = (); }; };
 		B56007111B3F6BD500A9A8F9 /* Into.swift in Sources */ = {isa = PBXBuildFile; fileRef = B56007101B3F6BD500A9A8F9 /* Into.swift */; };
 		B56007141B3F6C2800A9A8F9 /* SectionBy.swift in Sources */ = {isa = PBXBuildFile; fileRef = B56007131B3F6C2800A9A8F9 /* SectionBy.swift */; };
 		B56007161B4018AB00A9A8F9 /* MigrationChain.swift in Sources */ = {isa = PBXBuildFile; fileRef = B56007151B4018AB00A9A8F9 /* MigrationChain.swift */; };
@@ -115,6 +116,7 @@
 		2F291E2619C6D3CF007AF63F /* CoreStore.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; lineEnding = 0; path = CoreStore.swift; sourceTree = "<group>"; };
 		B504D0D51B02362500B2BBB1 /* CoreStore+Setup.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "CoreStore+Setup.swift"; sourceTree = "<group>"; };
 		B51BE0691B47FC4B0069F532 /* NSManagedObjectModel+Setup.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "NSManagedObjectModel+Setup.swift"; sourceTree = "<group>"; };
+		B54A6A541BA15F2A007870FD /* FetchedResultsControllerDelegate.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = FetchedResultsControllerDelegate.swift; sourceTree = "<group>"; };
 		B56007101B3F6BD500A9A8F9 /* Into.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = Into.swift; sourceTree = "<group>"; };
 		B56007131B3F6C2800A9A8F9 /* SectionBy.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = SectionBy.swift; sourceTree = "<group>"; };
 		B56007151B4018AB00A9A8F9 /* MigrationChain.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = MigrationChain.swift; sourceTree = "<group>"; };
@@ -434,6 +436,7 @@
 				B51BE0691B47FC4B0069F532 /* NSManagedObjectModel+Setup.swift */,
 				B5E84F2D1AFF849C0064E85B /* WeakObject.swift */,
 				B5E834BA1B7691F3001D3D50 /* Functions.swift */,
+				B54A6A541BA15F2A007870FD /* FetchedResultsControllerDelegate.swift */,
 			);
 			path = Internal;
 			sourceTree = "<group>";
@@ -576,6 +579,7 @@
 				B504D0D61B02362500B2BBB1 /* CoreStore+Setup.swift in Sources */,
 				B5D1E22C19FA9FBC003B2874 /* NSError+CoreStore.swift in Sources */,
 				B5E84F131AFF847B0064E85B /* Where.swift in Sources */,
+				B54A6A551BA15F2A007870FD /* FetchedResultsControllerDelegate.swift in Sources */,
 				B5A261211B64BFDB006EB6D3 /* MigrationType.swift in Sources */,
 				B5E84F141AFF847B0064E85B /* DataStack+Querying.swift in Sources */,
 				B56007141B3F6C2800A9A8F9 /* SectionBy.swift in Sources */,
--- a/CoreStore/Internal/FetchedResultsControllerDelegate.swift
+++ b/CoreStore/Internal/FetchedResultsControllerDelegate.swift
@@ -0,0 +1,175 @@
+//
+//  FetchedResultsControllerDelegate.swift
+//  CoreStore
+//
+//  Copyright (c) 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
+
+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
+
+internal final class FetchedResultsControllerDelegate: NSObject, NSFetchedResultsControllerDelegate {
+    
+    // MARK: Internal
+    
+    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) {
+        
+        self.deletedSections = []
+        self.insertedSections = []
+        
+        self.handler?.controllerWillChangeContent(controller)
+    }
+    
+    @objc dynamic func controllerDidChangeContent(controller: NSFetchedResultsController) {
+        
+        self.handler?.controllerDidChangeContent(controller)
+    }
+    
+    @objc dynamic func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
+        
+        if #available(iOS 9, *) {
+            
+            self.handler?.controller(
+                controller,
+                didChangeObject: anObject,
+                atIndexPath: indexPath,
+                forChangeType: type,
+                newIndexPath: newIndexPath
+            )
+            return
+        }
+        
+        // Workaround 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 type {
+            
+        case .Move:
+            guard let indexPath = indexPath, let newIndexPath = newIndexPath else {
+                
+                return
+            }
+            if indexPath == newIndexPath
+                && self.deletedSections.contains(indexPath.section) {
+                    
+                    self.handler?.controller(
+                        controller,
+                        didChangeObject: anObject,
+                        atIndexPath: nil,
+                        forChangeType: .Insert,
+                        newIndexPath: indexPath
+                    )
+                    return
+            }
+            
+        case .Update:
+            guard let section = indexPath?.section else {
+                
+                return
+            }
+            if self.deletedSections.contains(section)
+                || self.insertedSections.contains(section) {
+                    
+                    return
+            }
+            
+        default:
+            break
+        }
+        
+        self.handler?.controller(
+            controller,
+            didChangeObject: anObject,
+            atIndexPath: indexPath,
+            forChangeType: type,
+            newIndexPath: newIndexPath
+        )
+    }
+    
+    @objc dynamic func controller(controller: NSFetchedResultsController, didChangeSection sectionInfo: NSFetchedResultsSectionInfo, atIndex sectionIndex: Int, forChangeType type: NSFetchedResultsChangeType) {
+        
+        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>()
+}
--- a/CoreStore/Observing/ListMonitor.swift
+++ b/CoreStore/Observing/ListMonitor.swift
@@ -955,7 +955,7 @@ extension ListMonitor: FetchedResultsControllerHandler {
    
    // MARK: FetchedResultsControllerHandler
    
-    private func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
+    internal func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
        
        switch type {
            
@@ -990,7 +990,6 @@ extension ListMonitor: FetchedResultsControllerHandler {
            )
            
        case .Move:
-            CoreStore.log(.Notice, message: "\(indexPath!) - \(newIndexPath!)")
            NSNotificationCenter.defaultCenter().postNotificationName(
                ListMonitorDidMoveObjectNotification,
                object: self,
@@ -1003,7 +1002,7 @@ extension ListMonitor: FetchedResultsControllerHandler {
        }
    }
    
-    private func controller(controller: NSFetchedResultsController, didChangeSection sectionInfo: NSFetchedResultsSectionInfo, atIndex sectionIndex: Int, forChangeType type: NSFetchedResultsChangeType) {
+    internal func controller(controller: NSFetchedResultsController, didChangeSection sectionInfo: NSFetchedResultsSectionInfo, atIndex sectionIndex: Int, forChangeType type: NSFetchedResultsChangeType) {
        
        switch type {
            
@@ -1032,7 +1031,7 @@ extension ListMonitor: FetchedResultsControllerHandler {
        }
    }
    
-    private func controllerWillChangeContent(controller: NSFetchedResultsController) {
+    internal func controllerWillChangeContent(controller: NSFetchedResultsController) {
        
        self.taskGroup.enter()
        NSNotificationCenter.defaultCenter().postNotificationName(
@@ -1041,7 +1040,7 @@ extension ListMonitor: FetchedResultsControllerHandler {
        )
    }
    
-    private func controllerDidChangeContent(controller: NSFetchedResultsController) {
+   internal func controllerDidChangeContent(controller: NSFetchedResultsController) {
        
        NSNotificationCenter.defaultCenter().postNotificationName(
            ListMonitorDidChangeListNotification,
@@ -1050,80 +1049,13 @@ extension ListMonitor: FetchedResultsControllerHandler {
        self.taskGroup.leave()
    }
    
-    private func controller(controller: NSFetchedResultsController, sectionIndexTitleForSectionName sectionName: String?) -> String? {
+   internal func controller(controller: NSFetchedResultsController, sectionIndexTitleForSectionName sectionName: String?) -> String? {
        
        return self.sectionIndexTransformer(sectionName: sectionName)
    }
 }


-// MARK: - FetchedResultsControllerHandler
-
-private 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
-
-private final class FetchedResultsControllerDelegate: NSObject, NSFetchedResultsControllerDelegate {
-    
-    // MARK: NSFetchedResultsControllerDelegate
-    
-    @objc dynamic func controllerWillChangeContent(controller: NSFetchedResultsController) {
-        
-        self.handler?.controllerWillChangeContent(controller)
-    }
-    
-    @objc dynamic func controllerDidChangeContent(controller: NSFetchedResultsController) {
-        
-        self.handler?.controllerDidChangeContent(controller)
-    }
-    
-    @objc dynamic func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?) {
-        
-        self.handler?.controller(controller, didChangeObject: anObject, atIndexPath: indexPath, forChangeType: type, newIndexPath: newIndexPath)
-    }
-    
-    @objc dynamic func controller(controller: NSFetchedResultsController, didChangeSection sectionInfo: NSFetchedResultsSectionInfo, atIndex sectionIndex: Int, forChangeType type: NSFetchedResultsChangeType) {
-        
-        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
-    
-    weak var handler: FetchedResultsControllerHandler?
-    weak var fetchedResultsController: NSFetchedResultsController? {
-        
-        didSet {
-            
-            oldValue?.delegate = nil
-            self.fetchedResultsController?.delegate = self
-        }
-    }
-    
-    deinit {
-        
-        self.fetchedResultsController?.delegate = nil
-    }
-}
-
-
 private let ListMonitorWillChangeListNotification = "ListMonitorWillChangeListNotification"
 private let ListMonitorDidChangeListNotification = "ListMonitorDidChangeListNotification"
 private let ListMonitorWillRefetchListNotification = "ListMonitorWillRefetchListNotification"
--- a/CoreStore/Observing/ObjectMonitor.swift
+++ b/CoreStore/Observing/ObjectMonitor.swift
@@ -268,7 +268,17 @@ 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 {
            
@@ -279,7 +289,7 @@ extension ObjectMonitor: FetchedResultsControllerHandler {
                userInfo: [UserInfoKeyObject: anObject]
            )
            
-        case .Update, .Move where indexPath == newIndexPath:
+        case .Update:
            NSNotificationCenter.defaultCenter().postNotificationName(
                ObjectMonitorDidUpdateObjectNotification,
                object: self,
@@ -291,58 +301,11 @@ 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
-        )
-    }
-}
-
-
-// MARK: - FetchedResultsControllerHandler
-
-private protocol FetchedResultsControllerHandler: class {
-    
-    func controller(controller: NSFetchedResultsController, didChangeObject anObject: AnyObject, atIndexPath indexPath: NSIndexPath?, forChangeType type: NSFetchedResultsChangeType, newIndexPath: NSIndexPath?)
-    
-    func controllerWillChangeContent(controller: NSFetchedResultsController)
-}
-
-
-// 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: AnyObject, 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
+        return sectionName
    }
 }