Revert ObjectMonitor to previous implementation

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

@@ -16,13 +16,13 @@ class ObjectObserverDemoViewController: UIViewController, ObjectObserver {
     
     func setPalette<O: ObjectRepresentation>(_ newValue: O?) where O.ObjectType == Palette {
         
-        guard self.monitor?.objectID() != newValue?.objectID() else {
+        guard self.monitor?.object?.objectID() != newValue?.objectID() else {
             
             return
         }
         if let newValue = newValue {
             
-            self.monitor = newValue.asObjectMonitor(in: ColorsDemo.stack)
+            self.monitor = newValue.asReadOnly(in: ColorsDemo.stack).map(ColorsDemo.stack.monitorObject(_:))
         }
         else {
             

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

@@ -73,9 +73,30 @@ extension Palette {
         
         return "H: \(self.hue.value)˚, S: \(round(self.saturation.value * 100.0))%, B: \(round(self.brightness.value * 100.0))%"
     }
-    
+}
+
+extension LiveObject where ObjectType == Palette {
+
+    var color: UIColor {
+
+        return UIColor(
+            hue: CGFloat(self.hue) / 360.0,
+            saturation: CGFloat(self.saturation),
+            brightness: CGFloat(self.brightness),
+            alpha: 1.0
+        )
+    }
+
+    var colorText: String {
+
+        return "H: \(self.hue)˚, S: \(round(self.saturation * 100.0))%, B: \(round(self.brightness * 100.0))%"
+    }
+}
+
+extension Palette {
+
     func setInitialValues(in transaction: BaseDataTransaction) {
-        
+
         self.hue .= Palette.randomHue()
         self.saturation .= Float(1.0)
         self.brightness .= Float(arc4random_uniform(70) + 30) / 100.0

CoreStoreDemo/CoreStoreDemo/SwiftUI Demo/SwiftUIView.swift

@@ -20,22 +20,6 @@ struct SwiftUIView: View {
     @ObservedObject
     var palettes: LiveList<Palette>
 
-    @available(iOS 13.0.0, *)
-    struct ColorCell: View {
-
-        @ObservedObject
-        var palette: LiveObject<Palette>
-
-        var body: some View {
-            HStack {
-                Color(palette.color)
-                    .cornerRadius(5)
-                    .frame(width: 30, height: 30, alignment: .leading)
-                Text(palette.colorText)
-            }
-        }
-    }
-
     var body: some View {
         NavigationView {
             List {
@@ -124,6 +108,22 @@ struct SwiftUIView: View {
     private var needsShowAlert = false
 }
 
+@available(iOS 13.0.0, *)
+struct ColorCell: View {
+
+    @ObservedObject
+    var palette: LiveObject<Palette>
+
+    var body: some View {
+        HStack {
+            Color(palette.color)
+                .cornerRadius(5)
+                .frame(width: 30, height: 30, alignment: .leading)
+            Text(palette.colorText)
+        }
+    }
+}
+
 @available(iOS 13.0.0, *)
 struct DetailView: View {
 

Sources/DiffableDataSource.CollectionView.swift

@@ -42,7 +42,7 @@ extension DiffableDataSource {
         public typealias ObjectType = O
 
         @nonobjc
-        public init(collectionView: UICollectionView, dataStack: DataStack, cellProvider: @escaping (UICollectionView, IndexPath, ObjectType) -> UICollectionViewCell?, supplementaryViewProvider: @escaping (UICollectionView, String, IndexPath) -> UICollectionReusableView? = { _, _, _ in nil }) {
+        public init(collectionView: UICollectionView, dataStack: DataStack, cellProvider: @escaping (UICollectionView, IndexPath, O) -> UICollectionViewCell?, supplementaryViewProvider: @escaping (UICollectionView, String, IndexPath) -> UICollectionReusableView? = { _, _, _ in nil }) {
 
             self.collectionView = collectionView
             self.cellProvider = cellProvider
@@ -77,7 +77,7 @@ extension DiffableDataSource {
             collectionView.dataSource = self
         }
 
-        public func apply(_ snapshot: ListSnapshot<ObjectType>, animatingDifferences: Bool = true) {
+        public func apply(_ snapshot: ListSnapshot<O>, animatingDifferences: Bool = true) {
 
             let diffableSnapshot = snapshot.diffableSnapshot
 //            if #available(iOS 13.0, tvOS 13.0, watchOS 6.0, macOS 10.15, *) {
@@ -199,7 +199,7 @@ extension DiffableDataSource {
         private weak var collectionView: UICollectionView?
 
         private let dataStack: DataStack
-        private let cellProvider: (UICollectionView, IndexPath, ObjectType) -> UICollectionViewCell?
+        private let cellProvider: (UICollectionView, IndexPath, O) -> UICollectionViewCell?
         private let supplementaryViewProvider: (UICollectionView, String, IndexPath) -> UICollectionReusableView?
         private var rawDataSource: Any!
 

Sources/DiffableDataSource.TableView.swift

@@ -48,7 +48,7 @@ extension DiffableDataSource {
         public typealias ObjectType = O
         
         @nonobjc
-        public init(tableView: UITableView, dataStack: DataStack, cellProvider: @escaping (UITableView, IndexPath, ObjectType) -> UITableViewCell?) {
+        public init(tableView: UITableView, dataStack: DataStack, cellProvider: @escaping (UITableView, IndexPath, O) -> UITableViewCell?) {
 
             self.tableView = tableView
             self.cellProvider = cellProvider
@@ -82,7 +82,7 @@ extension DiffableDataSource {
             tableView.dataSource = self
         }
 
-        public func apply(_ snapshot: ListSnapshot<ObjectType>, animatingDifferences: Bool = true) {
+        public func apply(_ snapshot: ListSnapshot<O>, animatingDifferences: Bool = true) {
 
             let diffableSnapshot = snapshot.diffableSnapshot
 //            if #available(iOS 13.0, tvOS 13.0, watchOS 6.0, macOS 10.15, *) {
@@ -221,7 +221,7 @@ extension DiffableDataSource {
         private weak var tableView: UITableView?
         
         private let dataStack: DataStack
-        private let cellProvider: (UITableView, IndexPath, ObjectType) -> UITableViewCell?
+        private let cellProvider: (UITableView, IndexPath, O) -> UITableViewCell?
         private var rawDataSource: Any!
         
 //        @available(iOS 13.0, tvOS 13.0, watchOS 6.0, macOS 10.15, *)

Sources/LiveObject.swift

@@ -88,10 +88,15 @@ public final class LiveObject<O: DynamicObject>: ObjectRepresentation, Hashable
         }
         return Self.init(objectID: self.id, context: context)
     }
+
+    public func asReadOnly(in dataStack: DataStack) -> O? {
+
+        return dataStack.unsafeContext().fetchExisting(self.id)
+    }
     
     public func asEditable(in transaction: BaseDataTransaction) -> O? {
         
-        return self.context.fetchExisting(self.id)
+        return transaction.unsafeContext().fetchExisting(self.id)
     }
     
     public func asSnapshot(in dataStack: DataStack) -> ObjectSnapshot<O>? {
@@ -113,11 +118,6 @@ public final class LiveObject<O: DynamicObject>: ObjectRepresentation, Hashable
         }
         return .init(objectID: self.id, context: context)
     }
-    
-    public func asObjectMonitor(in dataStack: DataStack) -> ObjectMonitor<O>? {
-        
-        return .init(objectID: self.id, context: dataStack.unsafeContext())
-    }
 
 
     // MARK: Equatable
@@ -354,12 +354,4 @@ extension LiveObject where O: CoreStoreObject {
 
         return self.snapshot[dynamicMember: member]
     }
-
-    /**
-     Returns the value for the property identified by a given key.
-     */
-    public subscript<T>(dynamicMember member: KeyPath<O, T>) -> T {
-
-        return self.object[keyPath: member]
-    }
 }

Sources/ObjectMonitor.swift

@@ -40,17 +40,22 @@ import CoreData
  Observers registered via `addObserver(_:)` are not retained. `ObjectMonitor` only keeps a `weak` reference to all observers, thus keeping itself free from retain-cycles.
  */
 @available(macOS 10.12, *)
-public final class ObjectMonitor<O: DynamicObject>: ObjectRepresentation, Equatable {
+public final class ObjectMonitor<O: DynamicObject>: Equatable {
+
+    /**
+     The object type represented by this `ObjectMonitor`
+     */
+    public typealias ObjectType = O
     
     /**
      Returns the `DynamicObject` instance being observed, or `nil` if the object was already deleted.
      */
-    public var object: ObjectType? {
+    public var object: O? {
         
         return self.fetchedResultsController
             .fetchedObjects?
             .first
-            .flatMap({ ObjectType.cs_fromRaw(object: $0) })
+            .flatMap({ O.cs_fromRaw(object: $0) })
     }
     
     /**
@@ -72,7 +77,7 @@ public final class ObjectMonitor<O: DynamicObject>: ObjectRepresentation, Equata
      
      - parameter observer: an `ObjectObserver` to send change notifications to
      */
-    public func addObserver<U: ObjectObserver>(_ observer: U) where U.ObjectEntityType == ObjectType {
+    public func addObserver<U: ObjectObserver>(_ observer: U) where U.ObjectEntityType == O {
         
         self.unregisterObserver(observer)
         self.registerObserver(
@@ -99,7 +104,7 @@ public final class ObjectMonitor<O: DynamicObject>: ObjectRepresentation, Equata
      
      - parameter observer: an `ObjectObserver` to unregister notifications to
      */
-    public func removeObserver<U: ObjectObserver>(_ observer: U) where U.ObjectEntityType == ObjectType {
+    public func removeObserver<U: ObjectObserver>(_ observer: U) where U.ObjectEntityType == O {
         
         self.unregisterObserver(observer)
     }
@@ -120,50 +125,9 @@ public final class ObjectMonitor<O: DynamicObject>: ObjectRepresentation, Equata
     public let userInfo = UserInfo()
     
     
-    // MARK: ObjectRepresentation
-    
-    public func objectID() -> O.ObjectID {
-        
-        return self.id
-    }
-    
-    public func asLiveObject(in dataStack: DataStack) -> LiveObject<O>? {
-        
-        let context = dataStack.unsafeContext()
-        return .init(objectID: self.id, context: context)
-    }
-    
-    public func asEditable(in transaction: BaseDataTransaction) -> O? {
-        
-        return self.context.fetchExisting(self.id)
-    }
-    
-    public func asSnapshot(in dataStack: DataStack) -> ObjectSnapshot<O>? {
-        
-        let context = dataStack.unsafeContext()
-        return .init(objectID: self.id, context: context)
-    }
-    
-    public func asSnapshot(in transaction: BaseDataTransaction) -> ObjectSnapshot<O>? {
-        
-        let context = transaction.unsafeContext()
-        return .init(objectID: self.id, context: context)
-    }
-    
-    public func asObjectMonitor(in dataStack: DataStack) -> ObjectMonitor<O>? {
-        
-        let context = dataStack.unsafeContext()
-        if self.context == context {
-            
-            return self
-        }
-        return .init(objectID: self.id, context: dataStack.unsafeContext())
-    }
-    
-    
     // MARK: Equatable
     
-    public static func == (lhs: ObjectMonitor<ObjectType>, rhs: ObjectMonitor<ObjectType>) -> Bool {
+    public static func == (lhs: ObjectMonitor<O>, rhs: ObjectMonitor<O>) -> Bool {
         
         return lhs === rhs
     }
@@ -173,7 +137,7 @@ public final class ObjectMonitor<O: DynamicObject>: ObjectRepresentation, Equata
         return lhs.fetchedResultsController === rhs.fetchedResultsController
     }
     
-    public static func ~= (lhs: ObjectMonitor<ObjectType>, rhs: ObjectMonitor<ObjectType>) -> Bool {
+    public static func ~= (lhs: ObjectMonitor<O>, rhs: ObjectMonitor<O>) -> Bool {
         
         return lhs === rhs
     }
@@ -194,7 +158,7 @@ public final class ObjectMonitor<O: DynamicObject>: ObjectRepresentation, Equata
     
     // MARK: Internal
     
-    internal init(objectID: ObjectType.ObjectID, context: NSManagedObjectContext) {
+    internal init(objectID: O.ObjectID, context: NSManagedObjectContext) {
         
         let fetchRequest = Internals.CoreStoreFetchRequest<NSManagedObject>()
         fetchRequest.entity = objectID.entity
@@ -207,8 +171,8 @@ public final class ObjectMonitor<O: DynamicObject>: ObjectRepresentation, Equata
         let fetchedResultsController = Internals.CoreStoreFetchedResultsController(
             context: context,
             fetchRequest: fetchRequest,
-            from: From<ObjectType>([objectID.persistentStore?.configurationName]),
+            from: From<O>([objectID.persistentStore?.configurationName]),
-            applyFetchClauses: Where<ObjectType>("SELF", isEqualTo: objectID).applyToFetchRequest
+            applyFetchClauses: Where<O>("SELF", isEqualTo: objectID).applyToFetchRequest
         )
         
         let fetchedResultsControllerDelegate = Internals.FetchedResultsControllerDelegate()
@@ -224,7 +188,7 @@ public final class ObjectMonitor<O: DynamicObject>: ObjectRepresentation, Equata
         self.lastCommittedAttributes = (self.object?.cs_toRaw().committedValues(forKeys: nil) as? [String: NSObject]) ?? [:]
     }
     
-    internal func registerObserver<U: AnyObject>(_ observer: U, willChangeObject: @escaping (_ observer: U, _ monitor: ObjectMonitor<ObjectType>, _ object: ObjectType) -> Void, didDeleteObject: @escaping (_ observer: U, _ monitor: ObjectMonitor<ObjectType>, _ object: ObjectType) -> Void, didUpdateObject: @escaping (_ observer: U, _ monitor: ObjectMonitor<ObjectType>, _ object: ObjectType, _ changedPersistentKeys: Set<String>) -> Void) {
+    internal func registerObserver<U: AnyObject>(_ observer: U, willChangeObject: @escaping (_ observer: U, _ monitor: ObjectMonitor<O>, _ object: O) -> Void, didDeleteObject: @escaping (_ observer: U, _ monitor: ObjectMonitor<O>, _ object: O) -> Void, didUpdateObject: @escaping (_ observer: U, _ monitor: ObjectMonitor<O>, _ object: O, _ changedPersistentKeys: Set<String>) -> Void) {
         
         Internals.assert(
             Thread.isMainThread,
@@ -320,7 +284,7 @@ public final class ObjectMonitor<O: DynamicObject>: ObjectRepresentation, Equata
         return self.fetchedResultsController.managedObjectContext
     }
     
-    private func registerChangeNotification(_ notificationKey: UnsafeRawPointer, name: Notification.Name, toObserver observer: AnyObject, callback: @escaping (_ monitor: ObjectMonitor<ObjectType>) -> Void) {
+    private func registerChangeNotification(_ notificationKey: UnsafeRawPointer, name: Notification.Name, toObserver observer: AnyObject, callback: @escaping (_ monitor: ObjectMonitor<O>) -> Void) {
         
         Internals.setAssociatedRetainedObject(
             Internals.NotificationObserver(
@@ -340,7 +304,7 @@ public final class ObjectMonitor<O: DynamicObject>: ObjectRepresentation, Equata
         )
     }
     
-    private func registerObjectNotification(_ notificationKey: UnsafeRawPointer, name: Notification.Name, toObserver observer: AnyObject, callback: @escaping (_ monitor: ObjectMonitor<ObjectType>, _ object: ObjectType) -> Void) {
+    private func registerObjectNotification(_ notificationKey: UnsafeRawPointer, name: Notification.Name, toObserver observer: AnyObject, callback: @escaping (_ monitor: ObjectMonitor<O>, _ object: O) -> Void) {
         
         Internals.setAssociatedRetainedObject(
             Internals.NotificationObserver(
@@ -354,7 +318,7 @@ public final class ObjectMonitor<O: DynamicObject>: ObjectRepresentation, Equata
                             
                             return
                     }
-                    callback(self, ObjectType.cs_fromRaw(object: object))
+                    callback(self, O.cs_fromRaw(object: object))
                 }
             ),
             forKey: notificationKey,

Sources/ObjectRepresentation.swift

@@ -47,9 +47,14 @@ public protocol ObjectRepresentation {
      An instance that may be observed for object changes.
      */
     func asLiveObject(in dataStack: DataStack) -> LiveObject<ObjectType>?
+
+    /**
+     A read-only instance in the `DataStack`.
+     */
+    func asReadOnly(in dataStack: DataStack) -> ObjectType?
     
     /**
-     An instance that may be mutated within a transaction.
+     An instance that may be mutated within a `BaseDataTransaction`.
      */
     func asEditable(in transaction: BaseDataTransaction) -> ObjectType?
     
@@ -62,11 +67,6 @@ public protocol ObjectRepresentation {
      A thread-safe `struct` that is a full-copy of the object's properties
      */
     func asSnapshot(in transaction: BaseDataTransaction) -> ObjectSnapshot<ObjectType>?
-    
-    /**
-     An instance that may be observed for property-specific changes.
-     */
-    func asObjectMonitor(in dataStack: DataStack) -> ObjectMonitor<ObjectType>?
 }
 
 extension NSManagedObject: ObjectRepresentation {}
@@ -88,6 +88,16 @@ extension DynamicObject where Self: ObjectRepresentation {
         return .init(objectID: self.cs_id(), context: context)
     }
 
+    public func asReadOnly(in dataStack: DataStack) -> Self? {
+
+        let context = dataStack.unsafeContext()
+        if self.cs_toRaw().managedObjectContext == context {
+
+            return self
+        }
+        return context.fetchExisting(self.cs_id())
+    }
+
     public func asEditable(in transaction: BaseDataTransaction) -> Self? {
 
         let context = transaction.unsafeContext()
@@ -109,10 +119,4 @@ extension DynamicObject where Self: ObjectRepresentation {
         let context = transaction.unsafeContext()
         return .init(objectID: self.cs_id(), context: context)
     }
-
-    public func asObjectMonitor(in dataStack: DataStack) -> ObjectMonitor<Self>? {
-
-        let context = dataStack.unsafeContext()
-        return .init(objectID: self.cs_id(), context: context)
-    }
 }

Sources/ObjectSnapshot.swift

@@ -56,10 +56,15 @@ public struct ObjectSnapshot<O: DynamicObject>: SnapshotResult, ObjectRepresenta
         let context = dataStack.unsafeContext()
         return .init(objectID: self.id, context: context)
     }
+
+    public func asReadOnly(in dataStack: DataStack) -> O? {
+
+        return dataStack.unsafeContext().fetchExisting(self.id)
+    }
     
     public func asEditable(in transaction: BaseDataTransaction) -> O? {
         
-        return self.context.fetchExisting(self.id)
+        return transaction.unsafeContext().fetchExisting(self.id)
     }
     
     public func asSnapshot(in dataStack: DataStack) -> ObjectSnapshot<O>? {
@@ -81,11 +86,6 @@ public struct ObjectSnapshot<O: DynamicObject>: SnapshotResult, ObjectRepresenta
         }
         return .init(objectID: self.id, context: context)
     }
-    
-    public func asObjectMonitor(in dataStack: DataStack) -> ObjectMonitor<O>? {
-        
-        return .init(objectID: self.id, context: dataStack.unsafeContext())
-    }
 
 
     // MARK: Equatable
@@ -112,7 +112,7 @@ public struct ObjectSnapshot<O: DynamicObject>: SnapshotResult, ObjectRepresenta
 
         self.id = objectID
         self.context = context
-        self.values = O.cs_snapshotDictionary(id: id, context: context) as NSDictionary
+        self.values = O.cs_snapshotDictionary(id: objectID, context: context) as NSDictionary
     }