My app uses iCloud to let users sync their files via their private iCloud Drive, which does not use CloudKit. FileManager.default.url(forUbiquityContainerIdentifier: nil)?.appending(component: "Documents") I plan to transfer my app to another developer account, but I'm afraid it will affect the access of the app to the existing files in that folder. Apple documentation doesn't mention this case. Has anyone done this before and can confirm if the app will continue to work normally after transferring? Thanks

I've realized that I need to use migration plans, but those required versioned schemas. I think I've updated mine, but I wanted to confirm if this was the proper procedure. To start, none of my models were versioned. I've since wrapped them in a VersionedSchema like this: enum TagV1: VersionedSchema { static var versionIdentifier: Schema.Version = .init(1, 0, 0) static var models: [any PersistentModel.Type] { [Tag.self] } @Model final class Tag { var id = UUID() var name: String = "" // Relationships var transactions: [Transaction]? = nil init(name: String) { self.name = name } } } I also created a type alias to point to this. typealias Tag = TagV1.Tag This is what my container looks like in my app file. var sharedModelContainer: ModelContainer = { let schema = Schema([ Tag.self ]) let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false) do { return try ModelContainer(for: schema, configurations: [modelConfiguration]) } catch { fatalError("Could not create ModelContainer: \(error)") } }() The application builds and run successfully. Does this mean that my models are successfully versioned now? I'm trying to avoid an error I came across in earlier testing. That occurred because none of my models were versioned and I tried to setup a migration plan Cannot use staged migration with an unknown coordinator model version.

I've been struggling to get a ValueTransformer to work while developing in Xcode 16 for iOS 18. Despite thinking I had everything set up correctly, I keep encountering the following error whenever I create a tag: let tag = Tag(name: name, color: color.toPlatformColor()) // Converts it to NSColor or UIColor modelContext.insert(tag) SwiftData/DataUtilities.swift:184: Fatal error: Unable to determine the primitive for Attribute - name: color, options: [transformable with Optional("ColorTransformer")], valueType: UIColor, defaultValue: UIExtendedSRGBColorSpace 0 0 1 1, hashModifier: nil Here’s what I’m dealing with: Tag Model: @Model public final class Tag: Identifiable { var name: String = "" @Attribute(.transformable(by: ColorTransformer.self)) var color: PlatformColor = PlatformColor.blue init(name: String, color: PlatformColor) { self.name = name self.color = color } } ColorTransformer: final class ColorTransformer: ValueTransformer { override func transformedValue(_ value: Any?) -> Any? { guard let color = value as? PlatformColor else { return nil } do { let data = try NSKeyedArchiver.archivedData( withRootObject: color, requiringSecureCoding: true) return data } catch { assertionFailure("Failed to transform `PlatformColor` to `Data`") return nil } } override func reverseTransformedValue(_ value: Any?) -> Any? { guard let data = value as? NSData else { return PlatformColor.black } do { let color = try NSKeyedUnarchiver.unarchivedObject( ofClass: PlatformColor.self, from: data as Data) return color } catch { assertionFailure("Failed to transform `Data` to `PlatformColor`") return nil } } override class func transformedValueClass() -> AnyClass { return PlatformColor.self } override class func allowsReverseTransformation() -> Bool { return true } public static func register() { ValueTransformer.setValueTransformer(ColorTransformer(), forName: .colorTransformer) } } extension NSValueTransformerName { static let colorTransformer = NSValueTransformerName(rawValue: "ColorTransformer") } Platform Alias: #if os(macOS) typealias PlatformColor = NSColor #else typealias PlatformColor = UIColor #endif The ValueTransformer is registered when the ModelContainer is created at app startup: var sharedModelContainer: ModelContainer = { ColorTransformer.register() // Other configurations... }() I've also tried not aliasing the colors to see if that changes anything, but I still encounter the same issue. Any guidance or suggestions would be greatly appreciated!

I have been working on an app for the past few months, and one issue that I have encountered a few times is an error where quick subsequent deletions cause issues with detached tasks that are triggered from some user actions. Inside a Task.detached, I am building an isolated model context, querying for LineItems, then iterating over those items. The crash happens when accessing a Transaction property through a relationship. var byTransactionId: [UUID: [LineItem]] { return Dictionary(grouping: self) { item in item.transaction?.id ?? UUID() } } In this case, the transaction has been deleted, but the relationship existed when the fetch occurred, so the transaction value is non-nil. The crash occurs when accessing the id. This is the error. SwiftData/BackingData.swift:1035: Fatal error: This model instance was invalidated because its backing data could no longer be found the store. PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(backing: SwiftData.PersistentIdentifier.PersistentIdentifierBacking.managedObjectID(0xb43fea2c4bc3b3f5 <x-coredata://A9EFB8E3-CB47-48B2-A7C4-6EEA25D27E2E/Transaction/p1756>))) I see other posts about this error and am exploring some suggestions, but if anyone has any thoughts, they would be appreciated.

I am working on an app that will have about 200mb of data in a database. I would like to install a json file with 3-4 mb on the phone with the app, and then be able to send small packets of information to the user of the app as they are using the app, for example if they hit a button with a link to an instagram page, I can have the database/server send the link to the app, it will be just small bits of information going from the database to the phone, and perhaps I would do some location tracking and getting some information from the user to build up personal preferences etc. I'm wondering if coredata would be the best way to get smaller packets of information to the phone quickly or if I should think about firebase or something else. I was interested in using Cloudkit, but it seems like Cloudkit is really more about syncing devices and for getting information from the user to the database. It's been really hard to find any information about the strengths versus weaknesses of different databases and how they interact with mobile apps.

I'm working on an app that is using Core Data. I have a custom big number class that boils down to a double and an integer, plus math functions. I've been using transformable types to store these big numbers, but its forcing me to do a lot of ugly casts since the number class is used throughout the application. I figure I can either have my stored values be named differently (e.g. prefix with underscore) and have a computed variable to cast it to the correct type, or find some way to move the big number class to being an NSManagedObject. The issue with this is that the inverse relationships would be massive for the big number class, since multiple entities use the class in multiple properties already. Would it be recommended that I just keep using Transformable types and casts to handle this, or is there some standard way to handle a case like this in Core Data relationships?

I have an app and widget that share access to a SwiftData container using App Groups. I have implemented a SwiftData migration plan, but I am unsure whether I should allow the widget to perform the migration (in addition to the app). I am concerned about two possible issues: If the app and widget are run at approximately the same time (e.g. the user taps Open after doing a manual update in the App Store), then both the app and widget might try to perform the migration at the same time, which could lead to race conditions / data corruption. If the widget is first to run but the widget gets suspended for some reasons (e.g., iOS decides it's using too many resources), then the migration might be suspended leaving the database in an corrupted state. To me, it feels like the safest option is to only allow the app itself to perform the migration – this will ensure that the migration can only happen once in a safe state. However, this will lead to problems for the widget. For example, if the user does not open the app for several days after an automatic update, the widget will be in a broken state, since it will not be able to open the container until it has been migrated by the app. Possible solutions I'm considering: Allow both the app and widget to perform the migration and cross my fingers. (Ignore Issue 1 and Issue 2) Implement some kind of UserDefaults flag that is set to true during migration, so that the app and widget will avoid performing the migration concurrently. (Solves Issue 1 but not Issue 2) Only perform the migration in the app, and then add code to the widget to detect which container version the widget has access to, so that the widget can continue to work with a v1 container until the app eventually updates it to a v2 container. (Solves Issue 1 and Issue 2, but leads to very convoluted code – especially over time) Things I'm unsure about: Will iOS continue to use v1 of the widget until the app is opened for the first time, at which point v2 of the widget is installed? Or does iOS immediately update the widget to v2 on update? Does iOS immediately refresh the widget timeline on update? Does SwiftData already have some logic to avoid migrations being performed twice, even from different threads? If so, how does it respond if one process tries to access a container while another process is performing a migration? Does anyone have any recommendations about how to handle these possible issues? What are best practices? Cheers!

Hi all, I am using SwiftData and cloudkit and I am having an extremely persistent bug. I am building an education section on a app that's populated with lessons via a local JSON file. I don't need this lesson data to sync to cloudkit as the lessons are static, just need them imported into swiftdata so I've tried to use the modelcontainer like this: static func createSharedModelContainer() -> ModelContainer { // --- Define Model Groups --- let localOnlyModels: [any PersistentModel.Type] = [ Lesson.self, MiniLesson.self, Quiz.self, Question.self ] let cloudKitSyncModels: [any PersistentModel.Type] = [ User.self, DailyTip.self, UserSubscription.self, UserEducationProgress.self // User progress syncs ] However, what happens is that I still get Lesson and MiniLesson record types on cloudkit and for some reason as well, whenever I update the data models or delete and reinstall the app on simulator, the lessons duplicate (what seems to happen is that a set of lessons comes from the JSON file as it should), and then 1-2 seconds later, an older set of lessons gets synced from cloudkit. I can delete the old set of lessons if I just delete the lessons and mini lessons record types, but if I update the data model again, this error reccurrs. Sorry, I don't know if I managed to explain this well but essentially I just want to stop the lessons and minilessons from being uploaded to cloudkit as I think this will fix the problem. Am I doing something wrong with the code?

The stuff I've found by searching has confused me, so hopefully someone can help simplify it for me? I have an app (I use it for logging which books I've given away), and I could either add a bunch of things to the app, or I could have another app (possibly a CLI tool) to generate some reports I'd like.

I have a CoreData model with two configuration - but several problems. Notably the viewContext only shows data from the .private configuration. Here is the setup: The private configuration holds entities, for example, User and Course and the shared one holds entities, for example, Player and League. I setup the NSPersistentStoreDescriptions to use the same container but with a databaseScope of .private/.shared and with the configuration of "Private"/"Shared". loadPersistentStores() does not report an error. If I try container.initializeCloudKitSchema() only the .private configuration produces CKRecord types. If I create a companion app using one configuration (w/ all entities) the schema initialization creates all CKRecord types AND I can populate some data in the .private and a created CKShare. I see that data in the CloudKit dashboard. If I axe the companion app and run the real thing w/ two configurations, the viewContext only has the .private data. Why? If when querying history I use NSPersistentHistoryTransaction.fetchRequest I get a nil return when using two configurations (but non-nil when using one).

Hi, I'm developing an app for iOS and MacOS with SwiftData and CloudKit syncing. I had sync working very well with a set of models. This schema was also pushed to CloudKit production. Last week I added several models, and several relationship properties linking my existing models to newly added models. The schema updated just fine and everything worked. Then things went sideways: earlier this week I decided I wanted to rename a property on one of my new models. So I renamed the property, removed the application support folder for my local debug app (on Mac OS), removed the app from the iOS Simulator (to clear its local database), and finally reset my CloudKit container to its Production schema. Basically, I tried to go back to the same state I had as when I first added the new models. However, this time things don't go so smoothly, even after starting the app several times, rebooting my machine, turning iCloud on and off in Xcode and MacOS and iOS. When I look in CloudKit console, I see only my old models there: none of the new ones are added. I'd love some pointers on how I can best debug this issue, as I feel completely stuck. On MacOS I have very little mac-logs.txt to go on. Since the logs are a bit lengthy I've added them as an attachment. I get a few warnings, but it is unclear what they are warning me about. One thing that does stand out is that I am running the CloudKit in Development mode here. However, the logs do state accountPartition=Prod . And when I query CKContainer.default() for the container environment, the response is sandbox, which matches Development! On iOS The logs show a few errors, but I cannot make sense of them. error: CoreData+CloudKit: -[NSCloudKitMirroringDelegate _performSetupRequest:]_block_invoke(1240): <NSCloudKitMirroringDelegate: 0x600003d09860>: Failed to set up CloudKit integration for store: <NSSQLCore: 0x103325c90> (URL: file:///Users/bastiaan/Library/Developer/CoreSimulator/Devices/BF847CE5-A3E2-4B4C-8CD5-616B75B29AFE/data/Containers/Data/Application/0A916F67-B9B2-457B-8FA7-8C42819EA9AA/Library/Application%20Support/default.store) <CKError 0x600000c433f0: "Partial Failure" (2/1011); "Failed to modify some record zones"; partial errors: { com.apple.coredata.cloudkit.zone:__defaultOwner__ = <CKError 0x600000c956b0: "Internal Error" (1/5005); "Couldn't create new PCS blob for zone <CKRecordZoneID: 0x600000c475d0; zoneName=com.apple.coredata.cloudkit.zone, ownerName=__defaultOwner__>"> }> error: CoreData+CloudKit: -[NSCloudKitMirroringDelegate recoverFromError:](2310): <NSCloudKitMirroringDelegate: 0x600003d09860> - Attempting recovery from error: <CKError 0x600000c433f0: "Partial Failure" (2/1011); "Failed to modify some record zones"; partial errors: { com.apple.coredata.cloudkit.zone:__defaultOwner__ = <CKError 0x600000c956b0: "Internal Error" (1/5005); "Couldn't create new PCS blob for zone <CKRecordZoneID: 0x600000c475d0; zoneName=com.apple.coredata.cloudkit.zone, ownerName=__defaultOwner__>"> }> error: CoreData+CloudKit: -[NSCloudKitMirroringDelegate _recoverFromPartialError:forStore:inMonitor:]_block_invoke(2773): <NSCloudKitMirroringDelegate: 0x600003d09860>: Found unknown error as part of a partial failure: <CKError 0x600000c956b0: "Internal Error" (1/5005); "Couldn't create new PCS blob for zone <CKRecordZoneID: 0x600000c475d0; zoneName=com.apple.coredata.cloudkit.zone, ownerName=__defaultOwner__>"> error: CoreData+CloudKit: -[NSCloudKitMirroringDelegate _recoverFromPartialError:forStore:inMonitor:](2820): <NSCloudKitMirroringDelegate: 0x600003d09860>: Error recovery failed because the following fatal errors were found: { "<CKRecordZoneID: 0x600000c8fd50; zoneName=com.apple.coredata.cloudkit.zone, ownerName=__defaultOwner__>" = "<CKError 0x600000c956b0: \"Internal Error\" (1/5005); \"Couldn't create new PCS blob for zone <CKRecordZoneID: 0x600000c475d0; zoneName=com.apple.coredata.cloudkit.zone, ownerName=__defaultOwner__>\">"; } And in CloudKit logs I see: 06/11/2024, 9:09:59 UTC 738513AC-9326-42DE-B4E2-DA51F6462943 iOS;18.1 ZoneFetch EphemeralGroup { "time":"06/11/2024, 9:09:59 UTC" "database":"PRIVATE" "zone":"com.apple.coredata.cloudkit.zone" "userId":"_0d9445f850459ec351330ca0fde4134f" "operationId":"611BA98C9B10D3F2" "operationGroupName":"EphemeralGroup" "operationType":"ZoneFetch" "platform":"iPhone" "clientOS":"iOS;18.1" "overallStatus":"USER_ERROR" "error":"ZONE_NOT_FOUND" "requestId":"738513AC-9326-42DE-B4E2-DA51F6462943" "executionTimeMs":"53" "interfaceType":"NATIVE" } Any pointers are greatly appreciated! Bastiaan

In a document based SwiftData app for macOS, how do you go about opening a (modal) child window connected to the ModelContainer of the currently open document? Using .sheet() does not really result in a good UX, as the appearing view lacks the standard window toolbar. Using a separate WindowGroup with an argument would achieve the desired UX. However, as WindowGroup arguments need to be Hashable and Codable, there is no way to pass a ModelContainer or a ModelContext there: WindowGroup(id: "myWindowGroup", for: MyWindowGroupArguments.self) { $args in ViewThatOpensInAWindow(args: args) } Is there any other way?

I have an iOS app that writes files to its iCloud ubiquity container. The container is specified in Signing & Capabilities as iCloud.com.myappbusiness.myappid where "com.myappbusiness.myappid" is the bundle identifier. It works most of the time but for some users (less than 1%) it stops working at some point, most likely after any update of my app. Device reboot or app reinstallation does not help. What seems to help is turning off iCloud for the app in the iOS Settings (at which point the app saves files to the device locally) and then turning it on again. I cannot replicate the issue and have to rely on user feedback. I have tried various fixes over the past half a year, added retries after timeout, error handlers, tracing, etc. But the error always appears to someone after another app update. I have narrowed it down to the three lines of code below that check for the existence of the app iCloud container: NSFileManager* fileManager = [[NSFileManager alloc] init]; NSURL* containerUrl = [[fileManager URLForUbiquityContainerIdentifier:nil] URLByAppendingPathComponent:@"Documents"]; BOOL doesExist = [fileManager fileExistsAtPath:containerUrl.path]; doesExist returns NO when the issue happens. I.e. the app does not see its container and it looks like it does not exist. The folder should exist as this happens to long term users that have used the app before. Regarding the containerUrl, I can see it in the log that I get from the affected users and it is the correct path to the container, e.g. /private/var/mobile/Library/Mobile Documents/iCloud~com~myappbusiness~myappid/Documents I have tried the code above as it is and also within a file coordinator handler: [[[NSFileCoordinator alloc] initWithFilePresenter:nil] coordinateWritingItemAtURL:targetFileUrl options:NSFileCoordinatorWritingForReplacing error:&error byAccessor:^(NSURL * _Nonnull newURL) { ... the code here ... }]; I have run out of ideas what else to try. Is there anything obviously wrong with this approach or am I missing something in the code here? Is this a permission issue? Do I need to recreate the Documents folder if it's not accessible?

struct ModelContainerSetup { static let shared = ModelContainerSetup() private static let containerIdentifier = "iCloud.Journal" func setupModelContainer() -> ModelContainer { let schema = Schema([User.self]) let modelConfiguration = ModelConfiguration( schema: schema, isStoredInMemoryOnly: false, cloudKitDatabase: .private(Self.containerIdentifier) ) do { return try ModelContainer(for: schema, configurations: [modelConfiguration]) } catch { fatalError("Could not create ModelContainer: \(error)") } } **Expected Behavior: ** When CloudKit storage is full, the app should continue functioning with local storage Data should persist locally even if cloud sync fails Sync should resume when storage becomes available **Actual Behavior: ** ModelContainer initialization fails completely Local data also stops getting saved **Environment: ** iOS 17.0+ SwiftData Private CloudKit database Ideal Behaviour: When iCloud fails, the data should still be saved locally. I do not want to have two different containers so that I can maintain data consistency.

Hello, I'm currently developing an app using SwiftData. I want the app to use CloudKit to sync data, so I made sure all my model properties are optional. I've defined a Codable enum as follows: enum Size: Int, Codable { case small case medium case large } I've defined a Drink SwiftData model as follows: @Model class Drink { var name: String? var size: Size? init( name: String? = nil, size: Size? = nil ) { self.name = name self.size = size } } In one of my Views, I want to use a @Query to fetch the data, and use a Predicate to filter the data. The Predicate uses the size enumeration of the Drink model. Here is the code: struct DrinksView: View { @Query var drinks: [Drink] init() { let smallRawValue: Int = Size.small.rawValue let filter: Predicate<Drink> = #Predicate<Drink> { drink in if let size: Size = drink.size { return size.rawValue == smallRawValue } else { return false } } _drinks = Query(filter: filter) } var body: some View { List { ForEach(drinks) { drink in Text(drink.name ?? "Unknown Drink") } } } } The code compiles, but when I run the app, it crashes with the following error: Thread 1: Fatal error: Couldn't find \Drink.size!.rawValue on Drink with fields [SwiftData.Schema.PropertyMetadata(name: "name", keypath: \Drink.name, defaultValue: nil, metadata: nil), SwiftData.Schema.PropertyMetadata(name: "size", keypath: \Drink.size, defaultValue: nil, metadata: nil)] How can I filter my data using this optional variable on the Drink model? Thanks, Axel

I created 2 different schemas, and made a small change to one of them. I added a property to the model called "version". To see if the migration went through, I setup the migration plan to set version to "1.1.0" in willMigrate. In the didMigrate, I looped through the new version of Tags to check if version was set, and if not, set it. I did this incase the willMigrate didn't do what it was supposed to. The app built and ran successfully, but version was not set in the Tag I created in the app. Here's the migration: enum MigrationPlanV2: SchemaMigrationPlan { static var schemas: [any VersionedSchema.Type] { [DataSchemaV1.self, DataSchemaV2.self] } static let stage1 = MigrationStage.custom( fromVersion: DataSchemaV1.self, toVersion: DataSchemaV2.self, willMigrate: { context in let oldTags = try? context.fetch(FetchDescriptor<DataSchemaV1.Tag>()) for old in oldTags ?? [] { let new = Tag(name: old.name, version: "Version 1.1.0") context.delete(old) context.insert(new) } try? context.save() }, didMigrate: { context in let newTags = try? context.fetch(FetchDescriptor<DataSchemaV2.Tag>()) for tag in newTags ?? []{ if tag.version == nil { tag.version = "1.1.0" } } } ) static var stages: [MigrationStage] { [stage1] } } Here's the model container: var sharedModelContainer: ModelContainer = { let schema = Schema(versionedSchema: DataSchemaV2.self) let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false) do { return try ModelContainer( for: schema, migrationPlan: MigrationPlanV2.self, configurations: [modelConfiguration]) } catch { fatalError("Could not create ModelContainer: \(error)") } }() I ran a similar test prior to this, and got the same result. It's like the code in my willMigrate isn't running. I also had print statements in there that I never saw printed to the console. I tried to check the CloudKit console for any information, but I'm having issues with that as well (separate post). Anyways, how can I confirm that my migration was successful here?

Only development environment can real sync. But product environment can't sync. And when run my device show this error: CoreData: Already have a mirrored relationship registered for this key: CD_M2M_Event_items:B269B612-37A6-4ED7-9FDB-601E88BF56A8:8DC64E4A-E893-4465-8B21-48CF1C52A4BC <NSCKMirroredRelationship: 0x302bb9950> (entity: NSCKMirroredRelationship; id: 0xa049af3fb0190928 <x-coredata://BEB6E57C-891C-4E71-B92F-7BAA0844913E/NSCKMirroredRelationship/p1747>; data: { cdEntityName = Event; ckRecordID = "B5908A8A-079E-482C-9F2E-1309BF071F0E"; ckRecordSystemFields = nil; isPending = 0; isUploaded = 0; needsDelete = 0; recordName = "B269B612-37A6-4ED7-9FDB-601E88BF56A8"; recordZone = "0xa049af3f6a5909a8 <x-coredata://BEB6E57C-891C-4E71-B92F-7BAA0844913E/NSCKRecordZoneMetadata/p1>"; relatedEntityName = Item; relatedRecordName = "8DC64E4A-E893-4465-8B21-48CF1C52A4BC"; relationshipName = items; }) <decode: bad range for [%@] got [offs:941 len:665 within:0]> And my product core data sync data only to October 24, 2024. The data before October 24 was synchronized normally, Nothing after October 24 is synced.

In CloudKit console, i have a key named "Name" with String data type and i want to filter my query by that key. I can only query two record with name "Star" and "Kaizen", and i can't query the rest of the records. Can you help me with that.

I'm studying sharing through this link. I followed the first steps by changing the bundle identifier of the project, the tests and placing my own container in the config and in the info.plist. https://github.com/apple/sample-cloudkit-zonesharing The app appears and in the log it appears that it has managed to access my iCloud, but when I click on share and share something, the following message appears in the console, on the simulator and on the iPhone: "No options were found, providing default value for access type" "No options were found, providing default values ​​for permissions" "connection invalidated" And finally, when I click on the shared link, the following message appears: "Item unavailable The owner stopped sharing, or you don't have permission to open it."

While reading CkSyncEngine demo project code, I don't find the code to remove items in syncEngine.state.pendingRecordZoneChanges explicitly. I suspect it might occur in two possible places: nextRecordZoneChangeBatch() or ``nextRecordZoneChangeBatch()`, but I can't figure out how it occurs. nextRecordZoneChangeBatch() has the following code: let batch = await CKSyncEngine.RecordZoneChangeBatch(pendingChanges: changes) { recordID in if let contact = contacts[recordID.recordName] { let record = contact.lastKnownRecord ?? CKRecord(recordType: Contact.recordType, recordID: recordID) contact.populateRecord(record) return record } else { // We might have pending changes that no longer exist in our database. We can remove those from the state. syncEngine.state.remove(pendingRecordZoneChanges: [ .saveRecord(recordID) ]) return nil } } (I'll ignore the syncEngine.state.remove(pendingRecordZoneChanges:) in the else clause, because it's unrelated) Could it be that CKSyncEngine.RecordZoneChangeBatch.init(pendingChanges:,recordProvider:) automatically remove a CKRecord when the recordProvider: closure returns a non-nil value? I checked its document, but it doesn't say anything about this. Thanks for any help.