将数据迁移到应用程序组会禁用 iCloud 同步

Question

我正在向我现有的应用程序添加 Today Extension。我添加了一个应用程序组并使用这篇文章成功地将我的核心数据的数据迁移到了应用程序组的商店。我的应用程序同时使用 NSPersistentCloudKitContainer（当 iCloud 开启时）和一个 NSPersistentContainer（iCloud 关闭时）。虽然两个容器中的数据都成功迁移，但在使用 NSPersistentCloudKitContainer 时，我无法再在我的设备之间同步。在控制台中，我收到以下两个错误：

CoreData: 错误: CoreData+CloudKit: -[NSCloudKitMirroringDelegate _performSetupRequest:]_block_invoke(837): : 无法为商店设置 CloudKit 集成: (URL: file://path/name.sqlite)

错误域=NSCocoaErrorDomain 代码=134060 “发生核心数据错误。” UserInfo={NSLocalizedFailureReason=镜像委托无法初始化，因为它的存储已从协调器中删除。}

第一条错误消息的路径是切换到 App Groups 之前的 oldURL 的路径。所以我相信我只需要告诉 iCloud 不要尝试在该商店位置集成 CloudKit 并使用应用程序组的商店位置。

但我不知道如何做到这一点。任何人都可以帮忙吗？

核心数据代码：

class CoreDataManager {
    static let sharedManager = CoreDataManager()
    private init() {}

    lazy var persistentContainer: NSPersistentContainer = {
        var useCloudSync = UserDefaults.standard.bool(forKey: "useCloudSync")

        //Get the correct container
        let containerToUse: NSPersistentContainer?
        if useCloudSync {
           containerToUse = NSPersistentCloudKitContainer(name: "App")
        } else {
            containerToUse = NSPersistentContainer(name: "App")      
        }

        guard let container = containerToUse else {
            fatalError("Couldn't get a container")
        }

        //Set the storeDescription
        let storeURL = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "group.App")!.appendingPathComponent("\(container.name).sqlite")

        var defaultURL: URL?
        if let storeDescription = container.persistentStoreDescriptions.first, let url = storeDescription.url {
            defaultURL = FileManager.default.fileExists(atPath: url.path) ? url : nil
        }

        if defaultURL == nil {
            container.persistentStoreDescriptions = [NSPersistentStoreDescription(url: storeURL)]
        }


        let description = container.persistentStoreDescriptions.first else {
            fatalError("Hey Listen! ###\(#function): Failed to retrieve a persistent store description.")
        }

        description.setOption(true as NSNumber, forKey: NSPersistentStoreRemoteChangeNotificationPostOptionKey)
        if !useCloudSync {
            description.setOption(true as NSNumber, forKey: NSPersistentHistoryTrackingKey)
        }

        container.loadPersistentStores(completionHandler: { (storeDescription, error) in

            //migrate from old url to use app groups
            if let url = defaultURL, url.absoluteString != storeURL.absoluteString {
                let coordinator = container.persistentStoreCoordinator
                if let oldStore = coordinator.persistentStore(for: url) {
                    do {
                        try coordinator.migratePersistentStore(oldStore, to: storeURL, options: nil, withType: NSSQLiteStoreType)
                    } catch {
                        print("Hey Listen! Error migrating persistent store")
                        print(error.localizedDescription)
                    }

                    // delete old store
                    let fileCoordinator = NSFileCoordinator(filePresenter: nil)
                    fileCoordinator.coordinate(writingItemAt: url, options: .forDeleting, error: nil, byAccessor: { url in
                        do {
                            try FileManager.default.removeItem(at: url)
                        } catch {
                            print("Hey Listen! Error deleting old persistent store")
                            print(error.localizedDescription)
                        }
                    })
                }
            }
         }

         return container
   }
}

Answer 1

如果您仍然面临同样的问题，您应该为 storeDescription 添加以下行

storeDescription.cloudKitContainerOptions = NSPersistentCloudKitContainerOptions(containerIdentifier: "iCloud.com.yourapp.identifier")

来源：https : //developer.apple.com/videos/play/wwdc2019/202/

以下是我的 CoreDataStack：

import CoreData

class CoreDataStack {
    // MARK: - Core Data stack

    static var persistentContainer: NSPersistentCloudKitContainer = {
        /*
         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 = NSPersistentCloudKitContainer(name: "data")
        
        let storeURL = URL.storeURL(for: "group.com.myapp", databaseName: "data")
        let storeDescription = NSPersistentStoreDescription(url: storeURL)
        storeDescription.cloudKitContainerOptions = NSPersistentCloudKitContainerOptions(containerIdentifier: "iCloud.com.myapp")
        container.persistentStoreDescriptions = [storeDescription]
        
        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

    static 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)")
            }
        }
    }
}

public extension URL {
    /// Returns a URL for the given app group and database pointing to the sqlite database.
    static func storeURL(for appGroup: String, databaseName: String) -> URL {
        guard let fileContainer = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: appGroup) else {
            fatalError("Shared file container could not be created.")
        }

        return fileContainer.appendingPathComponent("\(databaseName).sqlite")
    }
}