Classe de configuração do Persistence

Persistence.swift

class PersistenceController: NSObject, ObservableObject {

    static let shared = PersistenceController()

    private let ckContainerID = "iCloud.com.devpoli.sample"
    private let appGroupContainerID = "group.com.devpoli.sample"

    lazy var persistentContainer: NSPersistentCloudKitContainer = {
        guard let modelURL = Bundle.main.url(forResource: "Sample", withExtension: "momd") else {
            fatalError("Unable to find data model in the bundle.")
        }

        guard let coreDataModel = NSManagedObjectModel(contentsOf: modelURL) else {
            fatalError("Unable to create the Core Data model.")
        }

        guard let appGroupURL = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: appGroupContainerID) else {
            fatalError("Unable to find App Group container")
        }

        let storeFolderUrl = appGroupURL.appending(component: "dataStore")
        let sharedStoreFolderUrl = storeFolderUrl.appending(path: "Shared")

        let fileManager = FileManager.default
        for folder in [sharedStoreFolderUrl] where !fileManager.fileExists(atPath: folder.path()) {
            do {
                try fileManager.createDirectory(at: folder, withIntermediateDirectories: true)
            } catch {
                fatalError("#\(#function): Failed to create the store folder: \(error)")
            }
        }

        let container = NSPersistentCloudKitContainer(name: "Sample")

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

        privateStoreDescription.url = appGroupURL.appending(component: "Sample.sqlite")
        privateStoreDescription.setOption(true as NSNumber, forKey: NSPersistentHistoryTrackingKey)
        privateStoreDescription.setOption(true as NSNumber, forKey: NSPersistentStoreRemoteChangeNotificationPostOptionKey)

        let cloudKitContainerOptions = NSPersistentCloudKitContainerOptions(containerIdentifier: ckContainerID)
        cloudKitContainerOptions.databaseScope = .private
        privateStoreDescription.cloudKitContainerOptions = cloudKitContainerOptions

        guard let sharedStoreDescription = privateStoreDescription.copy() as? NSPersistentStoreDescription else {
            fatalError("#\(#function): Copying the private store description returned an unexpected value.")
        }
        sharedStoreDescription.url = sharedStoreFolderUrl.appending(component: "SampleShared.sqlite")

        let sharedContainerOptions = NSPersistentCloudKitContainerOptions(containerIdentifier: ckContainerID)
        sharedContainerOptions.databaseScope = .shared
        sharedStoreDescription.cloudKitContainerOptions = sharedContainerOptions

        container.persistentStoreDescriptions.append(sharedStoreDescription)

        self._sharedPersistentStore = nil
        self._privatePersistentStore = nil

        container.loadPersistentStores { store, error in
            if let error = error as? NSError {
                fatalError("Unresolved error \(error), \(error.userInfo)")
            }

            guard let cloudKitContainerOptions = store.cloudKitContainerOptions else {
                return
            }

            if cloudKitContainerOptions.databaseScope == .private {
                self._privatePersistentStore = container.persistentStoreCoordinator.persistentStore(for: store.url!)
            } else if cloudKitContainerOptions.databaseScope == .shared {
                self._sharedPersistentStore = container.persistentStoreCoordinator.persistentStore(for: store.url!)
            }
        }

        container.viewContext.mergePolicy = NSMergeByPropertyObjectTrumpMergePolicy
        container.viewContext.transactionAuthor = TransactionAuthor.app

        container.viewContext.automaticallyMergesChangesFromParent = true

        do {
            try container.viewContext.setQueryGenerationFrom(.current)
        } catch {
            fatalError("#\(#function): Failed to pin viewContext to the current generation:\(error)")
        }

        return container
    }()

    private var _privatePersistentStore: NSPersistentStore?
    var privatePersistentStore: NSPersistentStore {
        return _privatePersistentStore!
    }

    private var _sharedPersistentStore: NSPersistentStore?
    var sharedPersistentStore: NSPersistentStore {
        return _sharedPersistentStore!
    }

    lazy var cloudKitContainer: CKContainer = {
        CKContainer(identifier: ckContainerID)
    }()
}