WIP: ObjectRepresentable

Sources/LiveObject.swift

@@ -50,8 +50,6 @@ public final class LiveObject<O: DynamicObject>: ObjectRepresentation, Hashable
 
         return self.lazySnapshot
     }
-
-    public private(set) lazy var object: O = self.context.fetchExisting(self.objectID)!
     
     public func addObserver<T: AnyObject>(_ observer: T, _ callback: @escaping (LiveObject<O>) -> Void) {
         
@@ -76,27 +74,49 @@ public final class LiveObject<O: DynamicObject>: ObjectRepresentation, Hashable
 
     public typealias ObjectType = O
     
-    public static func cs_fromRaw(object: NSManagedObject) -> Self {
+    public func objectID() -> O.ObjectID {
         
-        return self.init(
+        return self.id
-            objectID: object.objectID,
-            context: object.managedObjectContext!
-        )
     }
     
-    public func cs_id() -> O.ObjectID {
+    public func asLiveObject(in dataStack: DataStack) -> LiveObject<O>? {
         
-        return self.objectID
+        let context = dataStack.unsafeContext()
+        if self.context == context {
+            
+            return self
+        }
+        return Self.init(objectID: self.id, context: context)
     }
     
-    public func cs_object() -> O? {
+    public func asEditable(in transaction: BaseDataTransaction) -> O? {
         
-        return self.context.fetchExisting(self.objectID)
+        return self.context.fetchExisting(self.id)
     }
     
-    public func cs_rawObject(in context: NSManagedObjectContext) -> NSManagedObject? {
+    public func asSnapshot(in dataStack: DataStack) -> ObjectSnapshot<O>? {
         
-        return self.object.cs_toRaw()
+        let context = dataStack.unsafeContext()
+        if self.context == context {
+            
+            return self.lazySnapshot
+        }
+        return .init(id: self.id, context: context)
+    }
+    
+    public func asSnapshot(in transaction: BaseDataTransaction) -> ObjectSnapshot<O>? {
+        
+        let context = transaction.unsafeContext()
+        if self.context == context {
+            
+            return self.lazySnapshot
+        }
+        return .init(id: self.id, context: context)
+    }
+    
+    public func asObjectMonitor(in dataStack: DataStack) -> ObjectMonitor<O>? {
+        
+        return .init(objectID: self.id, context: dataStack.unsafeContext())
     }
 
 
@@ -104,7 +124,7 @@ public final class LiveObject<O: DynamicObject>: ObjectRepresentation, Hashable
 
     public static func == (_ lhs: LiveObject, _ rhs: LiveObject) -> Bool {
 
-        return lhs.objectID == rhs.objectID
+        return lhs.id == rhs.id
             && lhs.context == rhs.context
     }
 
@@ -113,7 +133,7 @@ public final class LiveObject<O: DynamicObject>: ObjectRepresentation, Hashable
 
     public func hash(into hasher: inout Hasher) {
 
-        hasher.combine(self.objectID)
+        hasher.combine(self.id)
         hasher.combine(self.context)
     }
 
@@ -141,7 +161,7 @@ public final class LiveObject<O: DynamicObject>: ObjectRepresentation, Hashable
 
     fileprivate init(objectID: O.ObjectID, context: NSManagedObjectContext, initializer: @escaping (NSManagedObjectID, NSManagedObjectContext) -> ObjectSnapshot<O>) {
 
-        self.objectID = objectID
+        self.id = objectID
         self.context = context
         if #available(iOS 13.0, tvOS 13.0, watchOS 6.0, macOS 10.15, *) {
 
@@ -175,7 +195,7 @@ public final class LiveObject<O: DynamicObject>: ObjectRepresentation, Hashable
 
     // MARK: Private
     
-    private let objectID: O.ObjectID
+    private let id: O.ObjectID
     private let context: NSManagedObjectContext
 
     @Internals.LazyNonmutating(uninitialized: ())

Sources/ObjectMonitor.swift

@@ -122,6 +122,44 @@ public final class ObjectMonitor<D: DynamicObject>: ObjectRepresentation, Equata
     
     // MARK: ObjectRepresentation
     
+    public func objectID() -> D.ObjectID {
+        
+        return self.id
+    }
+    
+    public func asLiveObject(in dataStack: DataStack) -> LiveObject<D>? {
+        
+        let context = dataStack.unsafeContext()
+        return .init(objectID: self.id, context: context)
+    }
+    
+    public func asEditable(in transaction: BaseDataTransaction) -> D? {
+        
+        return self.context.fetchExisting(self.id)
+    }
+    
+    public func asSnapshot(in dataStack: DataStack) -> ObjectSnapshot<D>? {
+        
+        let context = dataStack.unsafeContext()
+        return .init(id: self.id, context: context)
+    }
+    
+    public func asSnapshot(in transaction: BaseDataTransaction) -> ObjectSnapshot<D>? {
+        
+        let context = transaction.unsafeContext()
+        return .init(id: self.id, context: context)
+    }
+    
+    public func asObjectMonitor(in dataStack: DataStack) -> ObjectMonitor<D>? {
+        
+        let context = dataStack.unsafeContext()
+        if self.context == context {
+            
+            return self
+        }
+        return .init(objectID: self.id, context: dataStack.unsafeContext())
+    }
+    
     public typealias ObjectType = D
     
     public static func cs_fromRaw(object: NSManagedObject) -> Self {
@@ -181,14 +219,34 @@ public final class ObjectMonitor<D: DynamicObject>: ObjectRepresentation, Equata
     
     // MARK: Internal
     
-    internal convenience init<O: ObjectRepresentation>(dataStack: DataStack, object: O) where O.ObjectType == ObjectType {
+    internal init(objectID: ObjectType.ObjectID, context: NSManagedObjectContext) {
         
-        self.init(context: dataStack.mainContext, objectID: object.cs_id())
+        let fetchRequest = Internals.CoreStoreFetchRequest<NSManagedObject>()
-    }
+        fetchRequest.entity = objectID.entity
-    
+        fetchRequest.fetchLimit = 0
-    internal convenience init<O: ObjectRepresentation>(unsafeTransaction: UnsafeDataTransaction, object: O) where O.ObjectType == ObjectType {
+        fetchRequest.resultType = .managedObjectResultType
+        fetchRequest.sortDescriptors = []
+        fetchRequest.includesPendingChanges = false
+        fetchRequest.shouldRefreshRefetchedObjects = true
         
-        self.init(context: unsafeTransaction.context, objectID: object.cs_id())
+        let fetchedResultsController = Internals.CoreStoreFetchedResultsController(
+            context: context,
+            fetchRequest: fetchRequest,
+            from: From<ObjectType>([objectID.persistentStore?.configurationName]),
+            applyFetchClauses: Where<ObjectType>("SELF", isEqualTo: objectID).applyToFetchRequest
+        )
+        
+        let fetchedResultsControllerDelegate = Internals.FetchedResultsControllerDelegate()
+        
+        self.objectID = objectID
+        self.fetchedResultsController = fetchedResultsController
+        self.fetchedResultsControllerDelegate = fetchedResultsControllerDelegate
+        
+        fetchedResultsControllerDelegate.handler = self
+        fetchedResultsControllerDelegate.fetchedResultsController = fetchedResultsController
+        try! fetchedResultsController.performFetchFromSpecifiedStores()
+        
+        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) {
@@ -282,36 +340,6 @@ public final class ObjectMonitor<D: DynamicObject>: ObjectRepresentation, Equata
     private var didDeleteObjectKey: Void?
     private var didUpdateObjectKey: Void?
     
-    private init(context: NSManagedObjectContext, objectID: ObjectType.ObjectID) {
-        
-        let fetchRequest = Internals.CoreStoreFetchRequest<NSManagedObject>()
-        fetchRequest.entity = objectID.entity
-        fetchRequest.fetchLimit = 0
-        fetchRequest.resultType = .managedObjectResultType
-        fetchRequest.sortDescriptors = []
-        fetchRequest.includesPendingChanges = false
-        fetchRequest.shouldRefreshRefetchedObjects = true
-        
-        let fetchedResultsController = Internals.CoreStoreFetchedResultsController(
-            context: context,
-            fetchRequest: fetchRequest,
-            from: From<ObjectType>([objectID.persistentStore?.configurationName]),
-            applyFetchClauses: Where<ObjectType>("SELF", isEqualTo: objectID).applyToFetchRequest
-        )
-        
-        let fetchedResultsControllerDelegate = Internals.FetchedResultsControllerDelegate()
-        
-        self.objectID = objectID
-        self.fetchedResultsController = fetchedResultsController
-        self.fetchedResultsControllerDelegate = fetchedResultsControllerDelegate
-        
-        fetchedResultsControllerDelegate.handler = self
-        fetchedResultsControllerDelegate.fetchedResultsController = fetchedResultsController
-        try! fetchedResultsController.performFetchFromSpecifiedStores()
-        
-        self.lastCommittedAttributes = (self.object?.cs_toRaw().committedValues(forKeys: nil) as? [String: NSObject]) ?? [:]
-    }
-    
     private func registerChangeNotification(_ notificationKey: UnsafeRawPointer, name: Notification.Name, toObserver observer: AnyObject, callback: @escaping (_ monitor: ObjectMonitor<ObjectType>) -> Void) {
         
         Internals.setAssociatedRetainedObject(

Sources/ObjectRepresentation.swift

@@ -39,35 +39,66 @@ public protocol ObjectRepresentation {
     associatedtype ObjectType: DynamicObject
     
     /**
-     Used internally by CoreStore. Do not call directly.
+     The internal ID for the object.
      */
-    static func cs_fromRaw(object: NSManagedObject) -> Self
+    func objectID() -> ObjectType.ObjectID
     
     /**
-     Used internally by CoreStore. Do not call directly.
+     An instance that may be observed for object changes.
      */
-    func cs_id() -> ObjectType.ObjectID
+    func asLiveObject(in dataStack: DataStack) -> LiveObject<ObjectType>?
     
     /**
-     Used internally by CoreStore. Do not call directly.
+     An instance that may be mutated within a transaction.
      */
-    func cs_object() -> ObjectType?
+    func asEditable(in transaction: BaseDataTransaction) -> ObjectType?
     
     /**
-     Used internally by CoreStore. Do not call directly.
+     A thread-safe `struct` that is a full-copy of the object's properties
      */
-    func cs_rawObject(in context: NSManagedObjectContext) -> NSManagedObject?
+    func asSnapshot(in dataStack: DataStack) -> ObjectSnapshot<ObjectType>?
+    
+    /**
+     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 {}
+extension LiveObject {
+    
+    public static func cs_object(in context: NSManagedObjectContext) -> LiveObject<O>? {
+        
+        return nil
+    }
+}
 
-extension CoreStoreObject: ObjectRepresentation {}
+extension ObjectMonitor {
+    
+    public static func cs_object(in context: NSManagedObjectContext) -> LiveObject<D>? {
+        
+        return nil
+    }
+}
+
+extension NSManagedObject: ObjectRepresentation {
+    
+    
+}
+
+extension CoreStoreObject: ObjectRepresentation {
+    
+}
 
 extension DynamicObject where Self: ObjectRepresentation {
     
-    public func cs_object() -> Self? {
+    public static func cs_object(in context: NSManagedObjectContext) -> LiveObject<Self>? {
         
-        return self
+        fatalError()
     }
     
     public func cs_rawObject(in context: NSManagedObjectContext) -> NSManagedObject? {

Sources/ObjectSnapshot.swift

@@ -37,16 +37,55 @@ import AppKit
 // MARK: - ObjectSnapshot
 
 @dynamicMemberLookup
-public struct ObjectSnapshot<O: DynamicObject>: SnapshotResult, Identifiable, Hashable {
+public struct ObjectSnapshot<O: DynamicObject>: SnapshotResult, ObjectRepresentation, Hashable {
 
     // MARK: SnapshotResult
 
     public typealias ObjectType = O
-
+    
-
+    
-    // MARK: Identifiable
+    // MARK: ObjectRepresentation
-
+    
-    public let id: O.ObjectID
+    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()
+        if self.context == context {
+            
+            return self
+        }
+        return .init(id: self.id, context: context)
+    }
+    
+    public func asSnapshot(in transaction: BaseDataTransaction) -> ObjectSnapshot<O>? {
+        
+        let context = transaction.unsafeContext()
+        if self.context == context {
+            
+            return self
+        }
+        return .init(id: self.id, context: context)
+    }
+    
+    public func asObjectMonitor(in dataStack: DataStack) -> ObjectMonitor<O>? {
+        
+        return .init(objectID: self.id, context: dataStack.unsafeContext())
+    }
 
 
     // MARK: Equatable
@@ -79,6 +118,7 @@ public struct ObjectSnapshot<O: DynamicObject>: SnapshotResult, Identifiable, Ha
 
     // MARK: Private
 
+    private let id: O.ObjectID
     private let context: NSManagedObjectContext
     private let values: NSDictionary
 }