folder structure

Sources/Transactions/SynchronousDataTransaction.swift

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+//
+//  SynchronousDataTransaction.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
+
+
+// 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(_:)`.
+ */
+public final class SynchronousDataTransaction: BaseDataTransaction {
+    
+    /**
+     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(),
+            "Attempted to commit a \(typeName(self)) outside its designated queue."
+        )
+        CoreStore.assert(
+            !self.isCommitted,
+            "Attempted to commit a \(typeName(self)) more than once."
+        )
+        
+        self.isCommitted = true
+        
+        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
+     */
+    public func beginSynchronous(closure: (transaction: SynchronousDataTransaction) -> Void) -> SaveResult? {
+        
+        CoreStore.assert(
+            self.transactionQueue.isCurrentExecutionContext(),
+            "Attempted to begin a child transaction from a \(typeName(self)) outside its designated queue."
+        )
+        CoreStore.assert(
+            !self.isCommitted,
+            "Attempted to begin a child transaction from an already committed \(typeName(self))."
+        )
+        
+        return SynchronousDataTransaction(
+            mainContext: self.context,
+            queue: self.childTransactionQueue,
+            closure: closure).performAndWait()
+    }
+    
+    
+    // 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.
+     */
+    public override func create<T: NSManagedObject>(into: Into<T>) -> T {
+        
+        CoreStore.assert(
+            !self.isCommitted,
+            "Attempted to create an entity of type \(typeName(T)) from an already committed \(typeName(self))."
+        )
+        
+        return super.create(into)
+    }
+    
+    /**
+     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(
+            !self.isCommitted,
+            "Attempted to update an entity of type \(typeName(object)) from an already committed \(typeName(self))."
+        )
+        
+        return super.edit(object)
+    }
+    
+    /**
+     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(
+            !self.isCommitted,
+            "Attempted to update an entity of type \(typeName(T)) from an already committed \(typeName(self))."
+        )
+        
+        return super.edit(into, objectID)
+    }
+    
+    /**
+     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(
+            !self.isCommitted,
+            "Attempted to delete an entity of type \(typeName(object)) from an already committed \(typeName(self))."
+        )
+        
+        super.delete(object)
+    }
+    
+    /**
+     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(
+            !self.isCommitted,
+            "Attempted to delete an entities from an already committed \(typeName(self))."
+        )
+        
+        super.delete(([object1, object2] + objects).flatMap { $0 })
+    }
+    
+    /**
+     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,
+            "Attempted to delete an entities from an already committed \(typeName(self))."
+        )
+        
+        super.delete(objects)
+    }
+    
+    
+    // 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 {
+            
+            self.closure(transaction: self)
+            
+            if !self.isCommitted && self.hasChanges {
+                
+                CoreStore.log(
+                    .Warning,
+                    message: "The closure for the \(typeName(self)) completed without being committed. All changes made within the transaction were discarded."
+                )
+            }
+        }
+        return self.result
+    }
+    
+    
+    // MARK: Private
+    
+    private let closure: (transaction: SynchronousDataTransaction) -> Void
+    
+    
+    // MARK: Deprecated
+    
+    @available(*, deprecated=1.3.4, obsoleted=2.0.0, 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."
+        )
+        
+        self.context.reset()
+    }
+    
+    @available(*, deprecated=1.5.2, renamed="commitAndWait")
+    public func commit() {
+        
+        self.commitAndWait()
+    }
+}