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Swift 3でコアデータの軽量移行を有効にする

コアデータの軽量移行を有効にする正しい方法を読んだ記事によると、addPersistentStoreWithTypeにオプションを渡すことです。

let mOptions = [NSMigratePersistentStoresAutomaticallyOption: true,
NSInferMappingModelAutomaticallyOption: true]

try coordinator!.addPersistentStoreWithType(
NSSQLiteStoreType, configuration: nil, URL: url, options: mOptions)

しかし、私のXcode 8Swift 3プロジェクトaddPersistentStoreWithTypeが呼び出されている場所が見つかりません。これが唯一のcore dataプロジェクトを作成したときに生成されたコード：

 // MARK: - Core Data stack

lazy var persistentContainer: NSPersistentContainer = {
    /*
     The persistent container for the application. This implementation
     creates and returns a container, having loaded the store for the
     application to it. This property is optional since there are legitimate
     error conditions that could cause the creation of the store to fail.
    */
    let container = NSPersistentContainer(name: "Habits")
    container.loadPersistentStores(completionHandler: { (storeDescription, error) in
        if let error = error as NSError? {
            // Replace this implementation with code to handle the error appropriately.
            // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.

            /*
             Typical reasons for an error here include:
             * The parent directory does not exist, cannot be created, or disallows writing.
             * The persistent store is not accessible, due to permissions or data protection when the device is locked.
             * The device is out of space.
             * The store could not be migrated to the current model version.
             Check the error message to determine what the actual problem was.
             */
            fatalError("Unresolved error \(error), \(error.userInfo)")
        }
    })
    return container
}()

// MARK: - Core Data Saving support

func saveContext () {
    let context = persistentContainer.viewContext
    if context.hasChanges {
        do {
            try context.save()
        } catch {
            // Replace this implementation with code to handle the error appropriately.
            // fatalError() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
            let nserror = error as NSError
            fatalError("Unresolved error \(nserror), \(nserror.userInfo)")
        }
    }
}

Swift 3？）を使用してXcode 8で軽量の移行を有効にするにはどうすればよいですか？

iosswiftxcodecore-dataswift3
17
James

これはNSPersistentStoreDescriptionを使用して行います。これは、Swift 3 updateでこれらすべてのオプションが移動される場所です。loadPersistentStoresを呼び出す前にこれを実行してください。

let description = NSPersistentStoreDescription()

description.shouldInferMappingModelAutomatically = true
description.shouldMigrateStoreAutomatically = true

container.persistentStoreDescriptions = [description]
32
Tom Harrington

Xcode 7で新しいプロジェクトを開始し、生成されたコアデータコードをコピーして新しい新しいプロジェクトに貼り付けるだけです！

Xcode 7でプロジェクトを作成し、Xcode 8に移行しました。これが生成されたコードです。 （軽量スタックの移行を有効にするための2つのオプションはすでに追加しています）

// MARK: - Core Data stack

lazy var applicationDocumentsDirectory: URL = {
    // The directory the application uses to store the Core Data store file. This code uses a directory named "com.MyApp" in the application's documents Application Support directory.
    let urls = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)
    return urls[urls.count-1]
}()

lazy var managedObjectModel: NSManagedObjectModel = {
    // The managed object model for the application. This property is not optional. It is a fatal error for the application not to be able to find and load its model.
    let modelURL = Bundle.main.url(forResource: "MyApp", withExtension: "momd")!
    return NSManagedObjectModel(contentsOf: modelURL)!
}()

lazy var persistentStoreCoordinator: NSPersistentStoreCoordinator = {
    // The persistent store coordinator for the application. This implementation creates and returns a coordinator, having added the store for the application to it. This property is optional since there are legitimate error conditions that could cause the creation of the store to fail.
    // Create the coordinator and store
    let coordinator = NSPersistentStoreCoordinator(managedObjectModel: self.managedObjectModel)
    let url = self.applicationDocumentsDirectory.appendingPathComponent("SingleViewCoreData.sqlite")
    var failureReason = "There was an error creating or loading the application's saved data."
    do {
        try coordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: url, options: [NSMigratePersistentStoresAutomaticallyOption: true,NSInferMappingModelAutomaticallyOption: true])
    } catch {
        // Report any error we got.
        var dict = [String: AnyObject]()
        dict[NSLocalizedDescriptionKey] = "Failed to initialize the application's saved data" as AnyObject?
        dict[NSLocalizedFailureReasonErrorKey] = failureReason as AnyObject?

        dict[NSUnderlyingErrorKey] = error as NSError
        let wrappedError = NSError(domain: "YOUR_ERROR_DOMAIN", code: 9999, userInfo: dict)
        // Replace this with code to handle the error appropriately.
        // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
        NSLog("Unresolved error \(wrappedError), \(wrappedError.userInfo)")
        abort()
    }

    return coordinator
}()

lazy var managedObjectContext: NSManagedObjectContext = {
    // Returns the managed object context for the application (which is already bound to the persistent store coordinator for the application.) This property is optional since there are legitimate error conditions that could cause the creation of the context to fail.
    let coordinator = self.persistentStoreCoordinator
    var managedObjectContext = NSManagedObjectContext(concurrencyType: .mainQueueConcurrencyType)
    managedObjectContext.persistentStoreCoordinator = coordinator
    return managedObjectContext
}()

// MARK: - Core Data Saving support

func saveContext () {
    if managedObjectContext.hasChanges {
        do {
            try managedObjectContext.save()
        } catch {
            // Replace this implementation with code to handle the error appropriately.
            // abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development.
            let nserror = error as NSError
            NSLog("Unresolved error \(nserror), \(nserror.userInfo)")
            abort()
        }
    }
}

上記をコピーして、アプリデリゲートに貼り付けることができます。

注意すべきことの1つは、この行を編集して、データモデルのURLを取得することです。

let modelURL = Bundle.main.url(forResource: "MyApp", withExtension: "momd")!
7
Sweeper

デフォルトでは、NSPersistentStoreのshouldInferMappingModelAutomaticallyとshouldMigrateStoreAutomaticallyはtrueであることに注意してください。

Appleリファレンス：

6
Michal

私の場合、置換ではなく新しい説明に追加します

let description = NSPersistentStoreDescription()
description.shouldInferMappingModelAutomatically = true
description.shouldMigrateStoreAutomatically = true
container.persistentStoreDescriptions.append(description)
4
Andrew Shon

新しいNSPersistentContainerでは、多くの実用的なデフォルトがあります。ほとんどの答えが与えるプロパティを設定する必要はありません。

コンテナーを作成してロードするだけです。

let container = NSPersistentContainer(name: dataModelName)
container.loadPersistentStores { storeDescription, error in
    // You may verify the default storeDescription has the right default for light migration
}
1
samwize