Files
CoreStore/CoreStore/Saving and Processing/BaseDataTransaction.swift
John Rommel Estropia 4ce3d5de3c undo interface
2015-12-05 18:21:21 +09:00

227 lines
8.8 KiB
Swift

//
// BaseDataTransaction.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
#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`.
*/
public /*abstract*/ class BaseDataTransaction {
// MARK: Object management
/**
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.
*/
public func create<T: NSManagedObject>(into: Into<T>) -> T {
CoreStore.assert(
self.bypassesQueueing || self.transactionQueue.isCurrentExecutionContext(),
"Attempted to create an entity of type \(typeName(T)) outside its designated queue."
)
let context = self.context
let entityClass = (into.entityClass as! NSManagedObject.Type)
if into.inferStoreIfPossible {
switch context.parentStack!.persistentStoreForEntityClass(entityClass, configuration: nil, inferStoreIfPossible: true) {
case (let persistentStore?, _):
let object = entityClass.createInContext(context) as! T
context.assignObject(object, toPersistentStore: persistentStore)
return object
case (.None, true):
fatalError("Attempted to create an entity of type \(typeName(entityClass)) with ambiguous destination persistent store, but the configuration name was not specified.")
default:
fatalError("Attempted to create an entity of type \(typeName(entityClass)), but a destination persistent store containing the entity type could not be found.")
}
}
else {
switch context.parentStack!.persistentStoreForEntityClass(entityClass, configuration: into.configuration, inferStoreIfPossible: false) {
case (let persistentStore?, _):
let object = entityClass.createInContext(context) as! T
context.assignObject(object, toPersistentStore: persistentStore)
return object
default:
if let configuration = into.configuration {
fatalError("Attempted to create an entity of type \(typeName(entityClass)) into the configuration \"\(configuration)\", which it doesn't belong to.")
}
else {
fatalError("Attempted to create an entity of type \(typeName(entityClass)) into the default configuration, which it doesn't belong to.")
}
}
}
}
/**
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(),
"Attempted to update an entity of type \(typeName(object)) outside its designated queue."
)
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`.
*/
@warn_unused_result
public func edit<T: NSManagedObject>(into: Into<T>, _ objectID: NSManagedObjectID) -> T? {
CoreStore.assert(
self.bypassesQueueing || self.transactionQueue.isCurrentExecutionContext(),
"Attempted to update an entity of type \(typeName(T)) outside its designated queue."
)
CoreStore.assert(
into.inferStoreIfPossible
|| (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 self.fetchExisting(objectID) as? T
}
/**
Deletes a specified `NSManagedObject`.
- parameter object: the `NSManagedObject` to be deleted
*/
public func delete(object: NSManagedObject?) {
CoreStore.assert(
self.bypassesQueueing || self.transactionQueue.isCurrentExecutionContext(),
"Attempted to delete an entity outside its designated queue."
)
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
*/
public func delete(object1: NSManagedObject?, _ object2: NSManagedObject?, _ objects: NSManagedObject?...) {
self.delete(([object1, object2] + objects).flatMap { $0 })
}
/**
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(),
"Attempted to delete entities outside their designated queue."
)
let context = self.context
objects.forEach { context.fetchExisting($0)?.deleteFromContext() }
}
// MARK: Internal
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, 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()
}
}
}