Hi, I'm using SwiftData in my app, and I want to sent data to iCloud with CloudKit, but I found that If the user turns off my App iCloud sync function in the settings App, the local data will also be deleted. A better way is maintaining the local data, just don't connect to iCloud.How should I do that? I need guidance!!! I'm just getting started with CloudKit And I would be appreciated!

As of 2025-05-03, when a macOS user enables iCloud Drive synchronization for Desktop & Documents in US region, does iCloud filter xattrs upon upload or later when downloading back to another macOS host? Or is it the case that iCloud has no filtering of third-party xattrs? Where can I find the technical document outlining exactly what iCloud does with xattrs set on macOS host files and folders synchronized with iCloud Drive?

In the future, is there any plans to have AppMigrationKit for macOS-Windows cross transfers (or Linux, ChromeOS, HarmonyOS NEXT, etc)? Additionally, will the migration framework remain just iOS <-> Android or will it extend to Windows tablets, ChromeOS Tablets, HarmonyOS NEXT, KaiOS, Series 30+, Linux mobile, etc.

I have one target building and filling the SwiftData store and then copying the same store file to another target of the app to use the contents. That worked fine from iOS 17 to iOS 26.0.1 Under iOS 26.1 I am getting following error: CoreData: error: This store file was previously used on a build with Persistence-1522 but is now running on a build with Persistence-1518. file:///Users/xxx/Library/Developer/CoreSimulator/Devices/0FE92EA2-57FA-4A5E-ABD0-DAB4DABC3E02/data/Containers/Data/Application/B44D3256-9B09-4A60-94E2-C5F11A6519E7/Documents/default.store What does it mean and how to get back to working app under iOS 26.1?

I'm looking for guidance how to mitigate this crash. It seems super deep inside Core Data' FRC fetchedObjects management. In my code, it's initiated by this viewContext.perform { [unowned self] in self.viewContext.mergeChanges(fromContextDidSave: notification) } which is directly followed by the stack trace below. Basically merging data from .NSManagedObjectContextDidSave notification from another NSManagedObjectContext. Nothing special, it works great for years, apart from these rare occurrences. Exception Type: EXC_CRASH (SIGABRT) Exception Codes: 0x0000000000000000, 0x0000000000000000 Exception Reason: -[__NSCFArray objectAtIndex:]: index (235) beyond bounds (234) Termination Reason: SIGNAL 6 Abort trap: 6 Triggered by Thread: 0 Last Exception Backtrace: 0 CoreFoundation 0x199e947cc __exceptionPreprocess + 164 (NSException.m:249) 1 libobjc.A.dylib 0x1971672e4 objc_exception_throw + 88 (objc-exception.mm:356) 2 CoreFoundation 0x199fc4258 _NSArrayRaiseBoundException + 368 (NSCFArray.m:22) 3 CoreFoundation 0x199e288a4 -[__NSCFArray objectAtIndex:] + 200 (NSCFArray.m:42) 4 CoreData 0x1a1e17338 -[_PFMutableProxyArray objectAtIndex:] + 40 (_PFArray.m:1860) 5 CoreData 0x1a1e1673c -[NSFetchedResultsController _updateFetchedObjectsWithInsertChange:] + 380 (NSFetchedResultsController.m:1582) 6 CoreData 0x1a1e1426c __82-[NSFetchedResultsController(PrivateMethods) _core_managedObjectContextDidChange:]_block_invoke + 2240 (NSFetchedResultsController.m:2171) 7 CoreData 0x1a1dcdf80 developerSubmittedBlockToNSManagedObjectContextPerform + 156 (NSManagedObjectContext.m:4002) 8 CoreData 0x1a1e41a44 -[NSManagedObjectContext performBlockAndWait:] + 216 (NSManagedObjectContext.m:4113) 9 CoreData 0x1a1e41034 -[NSFetchedResultsController _core_managedObjectContextDidChange:] + 124 (NSFetchedResultsController.m:2379) 10 CoreFoundation 0x199e632f4 __CFNOTIFICATIONCENTER_IS_CALLING_OUT_TO_AN_OBSERVER__ + 148 (CFNotificationCenter.c:701) 11 CoreFoundation 0x199e63210 ___CFXRegistrationPost_block_invoke + 88 (CFNotificationCenter.c:194) 12 CoreFoundation 0x199e63158 _CFXRegistrationPost + 436 (CFNotificationCenter.c:222) 13 CoreFoundation 0x199e6170c _CFXNotificationPost + 728 (CFNotificationCenter.c:1248) 14 Foundation 0x198a84ea4 -[NSNotificationCenter postNotificationName:object:userInfo:] + 92 (NSNotification.m:531) 15 CoreData 0x1a1e11650 -[NSManagedObjectContext _createAndPostChangeNotification:deletions:updates:refreshes:deferrals:wasMerge:] + 1736 (NSManagedObjectContext.m:8098) 16 CoreData 0x1a1e10e0c -[NSManagedObjectContext _postRefreshedObjectsNotificationAndClearList] + 164 (NSManagedObjectContext.m:7631) 17 CoreData 0x1a1e0fad8 -[NSManagedObjectContext _processRecentChanges:] + 100 (NSManagedObjectContext.m:7714) 18 CoreData 0x1a1e3563c -[NSManagedObjectContext _coreMergeChangesFromDidSaveDictionary:usingObjectIDs:withClientQueryGeneration:] + 3436 (NSManagedObjectContext.m:3723) 19 CoreData 0x1a1e34350 __116+[NSManagedObjectContext(_NSCoreDataSPI) _mergeChangesFromRemoteContextSave:intoContexts:withClientQueryGeneration:]_block_invoke_4 + 76 (NSManagedObjectContext.m:9531) 20 CoreData 0x1a1dcdf80 developerSubmittedBlockToNSManagedObjectContextPerform + 156 (NSManagedObjectContext.m:4002) 21 CoreData 0x1a1e41a44 -[NSManagedObjectContext performBlockAndWait:] + 216 (NSManagedObjectContext.m:4113) 22 CoreData 0x1a1e39880 +[NSManagedObjectContext _mergeChangesFromRemoteContextSave:intoContexts:withClientQueryGeneration:] + 2372 (NSManagedObjectContext.m:9537) 23 CoreData 0x1a1e344a0 -[NSManagedObjectContext mergeChangesFromContextDidSaveNotification:] + 292 (NSManagedObjectContext.m:0)

I'm experiencing a critical issue with SwiftData custom migrations where objects created during migration appear to be inserted successfully but aren't persisted or found by queries after migration completes. The migration logs show objects being created, but subsequent queries return zero results. I'm migrating from schema version V2 to V2_5, which involves: Renaming Person class to GroupData Keeping the same data structure but changing the class name while keeping the old class. Using a custom migration stage to copy data from old to new schema Below is an extract of my two schema and migration plan: Environment: Xcode 16.0, iOS 18.0, Swift 6.0 SchemaV2 enum LinkMapV2: VersionedSchema { static let versionIdentifier: Schema.Version = .init(2, 0, 0) static var models: [any PersistentModel.Type] { [AnnotationData.self, Person.self, History.self] } @Model final class Person { @Attribute(.unique) var id: UUID var name: String var photo: String var requirement: String var statue: Bool var annotationId: UUID? var number: Int = 0 init(id: UUID = UUID(), name: String = "", photo: String = "", requirement: String = "", status: Bool = false, annotationId: UUID? = nil, number: Int = 0) { self.id = id self.name = name self.photo = photo self.requirement = requirement self.statue = status self.annotationId = annotationId self.number = number } } } Schema V2_5 static let versionIdentifier: Schema.Version = .init(2, 5, 0) static var models: [any PersistentModel.Type] { [AnnotationData.self, Person.self, GroupData.self, History.self] } // Keep the old Person model for migration @Model final class Person { @Attribute(.unique) var id: UUID var name: String var photo: String var requirement: String var statue: Bool var annotationId: UUID? var number: Int = 0 init(id: UUID = UUID(), name: String = "", photo: String = "", requirement: String = "", status: Bool = false, annotationId: UUID? = nil, number: Int = 0) { self.id = id self.name = name self.photo = photo self.requirement = requirement self.statue = status self.annotationId = annotationId self.number = number } } // Add the new GroupData model that mirrors Person @Model final class GroupData { @Attribute(.unique) var id: UUID var name: String var photo: String var requirement: String var status: Bool var annotationId: UUID? var number: Int = 0 init(id: UUID = UUID(), name: String = "", photo: String = "", requirement: String = "", status: Bool = false, annotationId: UUID? = nil, number: Int = 0) { self.id = id self.name = name self.photo = photo self.requirement = requirement self.status = status self.annotationId = annotationId self.number = number } } } Migration Plan static let migrationV2toV2_5 = MigrationStage.custom( fromVersion: LinkMapV2.self, toVersion: LinkMapV2_5.self, willMigrate: { context in do { let persons = try context.fetch(FetchDescriptor<LinkMapV2.Person>()) print("=== MIGRATION STARTED ===") print("Found \(persons.count) Person objects to migrate") guard !persons.isEmpty else { print("No Person data requires migration") return } for person in persons { print("Migrating Person: '\(person.name)' with ID: \(person.id)") let newGroup = LinkMapV2_5.GroupData( id: person.id, // Keep the same ID name: person.name, photo: person.photo, requirement: person.requirement, status: person.statue, annotationId: person.annotationId, number: person.number ) context.insert(newGroup) print("Inserted new GroupData: '\(newGroup.name)'") // Don't delete the old Person yet to avoid issues // context.delete(person) } try context.save() print("=== MIGRATION COMPLETED ===") print("Successfully migrated \(persons.count) Person objects to GroupData") } catch { print("=== MIGRATION ERROR ===") print("Migration failed with error: \(error)") } }, didMigrate: { context in do { // Verify migration in didMigrate phase let groups = try context.fetch(FetchDescriptor<LinkMapV2_5.GroupData>()) let oldPersons = try context.fetch(FetchDescriptor<LinkMapV2_5.Person>()) print("=== MIGRATION VERIFICATION ===") print("New GroupData count: \(groups.count)") print("Remaining Person count: \(oldPersons.count)") // Now delete the old Person objects for person in oldPersons { context.delete(person) } if !oldPersons.isEmpty { try context.save() print("Cleaned up \(oldPersons.count) old Person objects") } // Print all migrated groups for debugging for group in groups { print("Migrated Group: '\(group.name)', Status: \(group.status), Number: \(group.number)") } } catch { print("Migration verification error: \(error)") } } ) And I've attached console output below: Console Output

I'm using SwiftData with CloutKit with a very simple app. Data syncs between iOS, iPadOS, and visionOS, but not macOS. From what I can tell, macOS is never getting CK messages unless I'm running the app from Xcode. I can listen for the CK messages and show a line in a debug overlay. This works perfectly when I run from Xcode. I can see the notifications and see updates in my app. However, if I just launch the app outside of Xcode I will never see any changes or notifications. It is as if the Mac app never even tries to contact CloudKit. Schema has been deployed in the CloudKit console. The app is based on the multi-platform Xcode template. Again, only the macOS version has this issue. Is there some extra permission or setting I need to set up in order to use CloudKit on macOS? @State private var publisher = NotificationCenter.default.publisher(for: NSPersistentCloudKitContainer.eventChangedNotification).receive(on: DispatchQueue.main) .onReceive(publisher) { notification in // Listen for changes in CK events if let userInfo = notification.userInfo, let event = userInfo[NSPersistentCloudKitContainer.eventNotificationUserInfoKey] as? NSPersistentCloudKitContainer.Event { let message = "CloudKit Sync: \(event.type.rawValue) - \(event.succeeded ? "Success" : "Failed") - \(event.description)" // Store for UI display syncNotifications.append(message) if syncNotifications.count > 10 { syncNotifications.removeFirst() } } } .overlay(alignment: .topTrailing) { if !syncNotifications.isEmpty { VStack(alignment: .leading) { ForEach(syncNotifications, id: \.self) { notification in Text(notification) .padding(8) } } .frame(width: 800, height: 500) .cornerRadius(8) .background(Color.secondary.opacity(0.2)) .padding() .transition(.move(edge: .top)) } }

Setup I am running a versionedSchema for my SwiftData model and attempting a migration. The new version contains a new attribute, with a type of a new custom enum defined in the @Model class, a default value, and a private(set). Migration was completed with a migrationPlan with nil values for willMigrate and didMigrate. Example - Previous Version @Model class MyNumber { var num: Int init() { // Init Code } } Example - Newest Version @Model class MyNumber { var num: Int private(set) var rounding: RoundAmount = MyNumber.RoundAmount.thirtyMinute init() { // Init Code } enum RoundAmount { case fiveMinute, tenMinute, thirtyMinute } } Issue Running this code, I get a swiftData error for “SwiftData/ModelCoders.swift:1585: nil value passed for a non-optional keyPath, /MyNumber.rounding” I assume this means a failure of the swiftData lightweight migration? I have reverted the version, removed private(set) and re-tried the migration with no success. Using the versionedSchema with migrationPlans, are lightweight migrations possible? Could this be an issue with the use of a custom enum? Other changes in my actual project migrated successfully so I’m lost on why I’m having this issue.

I get this error, i have my own DIKit, and i want to use swiftdata for showing info from persisten model. It works all over the app, but i get this error with my .sheet. // JobCreationView.swift // Features // // Created by Jens Vik on 26/03/2025. // import SwiftUI import DesignKit import DIKit import PresentationKit import CoreKit import DomainKit import SwiftData public struct JobCreationView: View { @Binding var isPresented: Bool // Inject view model using DIKit's property wrapper @Injected((any JobCreationViewModelProtocol).self) private var viewModel // Form state @Injected(ModelContext.self) private var modelContext @State private var date = Date() @State private var isASAP = false @State private var price = "" @State private var jobType = "Fiks" @State private var description = "" // Available job types private let jobTypes = ["Fiks", "Fiksit"] @Query private var userContexts: [UserContextModel] public init(isPresented: Binding<Bool>) { self._isPresented = isPresented print("DEBUG: JobCreationView initialized") } public var body: some View { let city = userContexts.first?.city ?? "Loading..." NavigationView { Form { Section(header: Text("Location")) { Text(city) } Section(header: Text("Details")) { TextField("Price", text: $price) .keyboardType(.numberPad) Picker("Job Type", selection: $jobType) { ForEach(jobTypes, id: \.self) { type in Text(type).tag(type) } } .pickerStyle(SegmentedPickerStyle()) TextEditor(text: $description) .frame(minHeight: 100) .overlay( RoundedRectangle(cornerRadius: 8) .stroke(Color.gray.opacity(0.2), lineWidth: 1) ) } } .navigationBarTitle("Create Job", displayMode: .inline) .navigationBarItems( leading: Button("Cancel") { isPresented = false }, trailing: Button("Post") { // Post functionality will be added later isPresented = false } .disabled( (!isASAP && date < Date()) || price.isEmpty || description.isEmpty) ) } } } How bad is this macro error? error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift" error: the replacement path doesn't exist: "/var/folders/dn/x3x4wwkd335_rl91by3tqx5w0000gn/T/swift-generated-sources/@_swiftmacro_10FeatureKit15JobCreationViewV12userContexts33_CDDE5BE156468A2E8CC9B6A7E34B1006LL5QueryfMa.swift"

Description: I'm experiencing a critical issue with SwiftData custom migrations where objects created during migration appear to be inserted successfully but aren't persisted or found by queries after migration completes. The migration logs show objects being created, but subsequent queries return zero results. Problem Details: I'm migrating from schema version V2 to V3, which involves: Renaming Person class to GroupData Keeping the same data structure but changing the class name Using a custom migration stage to copy data from old to new schema Migration Code: swift static let migrationV2toV3 = MigrationStage.custom( fromVersion: LinkMapV2.self, toVersion: LinkMapV3.self, willMigrate: { context in do { let persons = try context.fetch(FetchDescriptor<LinkMapV2.Person>()) print("Found (persons.count) Person objects to migrate") // ✅ Shows 11 objects for person in persons { let newGroup = LinkMapV3.GroupData( id: person.id, // Same UUID name: person.name, // ... other properties ) context.insert(newGroup) print("Inserted GroupData: '\(newGroup.name)'") // ✅ Confirms insertion } try context.save() // ✅ No error thrown print("Successfully migrated \(persons.count) objects") // ✅ Confirms save } catch { print("Migration error: \(error)") } }, didMigrate: { context in do { let groups = try context.fetch(FetchDescriptor<LinkMapV3.GroupData>()) print("Final GroupData count: \(groups.count)") // ❌ Shows 0 objects! } catch { print("Verification error: \(error)") } } ) Console Output: text === MIGRATION STARTED === Found 11 Person objects to migrate Migrating Person: 'Riverside of pipewall' with ID: 7A08C633-4467-4F52-AF0B-579545BA88D0 Inserted new GroupData: 'Riverside of pipewall' ... (all 11 objects processed) ... === MIGRATION COMPLETED === Successfully migrated 11 Person objects to GroupData === MIGRATION VERIFICATION === New GroupData count: 0 // ❌ PROBLEM: No objects found! What I've Tried: Multiple context approaches: Using the provided migration context Creating a new background context with ModelContext(context.container) Using context.performAndWait for thread safety Different save strategies: Calling try context.save() after insertions Letting SwiftData handle saving automatically Multiple save calls at different points Verification methods: Checking in didMigrate closure Checking in app's ContentView after migration completes Using both @Query and manual FetchDescriptor Schema variations: Direct V2→V3 migration Intermediate V2.5 schema with both classes Lightweight migration with @Attribute(originalName:) Current Behavior: Migration runs without errors Objects appear to be inserted successfully context.save() completes without throwing errors But queries in didMigrate and post-migration return empty results The objects seem to exist in a temporary state that doesn't persist Expected Behavior: Objects created during migration should be persisted and queryable Post-migration queries should return the migrated objects Data should be available in the main app after migration completes Environment: Xcode 16.0+ iOS 18.0+ SwiftData Swift 6.0+ Key Questions: Is there a specific way migration contexts should be handled for data to persist? Are there known issues with object persistence in custom migrations? Should we be using a different approach for class renaming migrations? Is there a way to verify that objects are actually being written to the persistent store? The migration appears to work perfectly until the verification step, where all created objects seem to vanish. Any guidance would be greatly appreciated! Additional Context from my investigation: I've noticed these warning messages during migration that might be relevant: text SwiftData.ModelContext: Unbinding from the main queue. This context was instantiated on the main queue but is being used off it. error: Persistent History (76) has to be truncated due to the following entities being removed: (Person) This suggests there might be threading or context lifecycle issues affecting persistence. Let me know if you need any additional information about my setup or migration configuration!

I have the following lines of code to access data through CoreData. import Foundation import CoreData import CloudKit class CoreDataManager { static let instance = CoreDataManager() let container: NSPersistentCloudKitContainer let context: NSManagedObjectContext init() { container = NSPersistentCloudKitContainer(name: "ABC") container.loadPersistentStores(completionHandler: { (storeDescription, error) in if let error = error as NSError? { print(error.userInfo) } }) context = container.viewContext context.automaticallyMergesChangesFromParent = true context.mergePolicy = NSMergePolicy(merge: .mergeByPropertyObjectTrumpMergePolicyType) } func save() { do { try container.viewContext.save() print("Saved successfully") } catch { print("Error in saving data: \(error.localizedDescription)") } } } I have confirmed that I can share data between iPhone and iPad. Now, I need to use AppGroup as well. I have changed my code as follows. import Foundation import CoreData import CloudKit class CoreDataManager { static let shared = CoreDataManager() let container: NSPersistentContainer let context: NSManagedObjectContext init() { container = NSPersistentCloudKitContainer(name: "ABC") container.persistentStoreDescriptions = [NSPersistentStoreDescription(url: FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "some group name")!.appendingPathComponent("CoreDataMama.sqlite"))] container.loadPersistentStores(completionHandler: { (description, error) in if let error = error as NSError? { print("Unresolved error \(error), \(error.userInfo)") } }) context = container.viewContext context.automaticallyMergesChangesFromParent = true context.mergePolicy = NSMergePolicy(merge: .mergeByPropertyObjectTrumpMergePolicyType) } func save() { do { try container.viewContext.save() print("Saved successfully") } catch { print("Error in saving data: \(error.localizedDescription)") } } } Other files being unaltered, my sample apps aren't sharing data. What am I doing wrong? Just FYI, I'm using actual devices. Thank you for your reading this topic.

Hello, I'm trying to work on an iPadOS and macOS app that will rely on the document-based system to create some kind of orientation task to follow. Let say task1.myfile will be a check point regulation from NYC to SF and task2.myfile will be a visit as many key location as you can in SF. The file represent the specific landmark location and rules of the game. And once open, I will be able to read KML/GPS file to evaluate their score based with the current task. But opened GPS files does not have to be stored in the task file itself, it stay alongside. I wanted to use that scenario to experiment with SwiftData (I'm a long time CoreData user, I even wrote my own WebDAV based persistent store back in the day), and so, mix both on file and in memory persistent store, with distribution based on object class. With CoreData it would have been possible, but I do not see how to achieve that with SwiftData and DocumentGroup integration. Any idea how to do that?

I've been seeing something that I find odd when using two SwiftData models where if I have one model (book, in this case) that has an optional array of another model (page, in this case), the optional array starts out as set to nil, but after about 20 seconds it updates to being an empty array. I see it in Previews and after building. Is this expected behavior? Should I just assume that if there is an optional array in my model it will eventually be initialized to an empty array? Code is below. import SwiftUI import SwiftData @Model final class Book { var title: String = "New Book" @Relationship var pages: [Page]? = nil init(title: String) { self.title = title } } @Model final class Page { var content: String = "Page Content" var book: Book? = nil init() { } } struct ContentView: View { @Environment(\.modelContext) private var modelContext @Query private var books: [Book] var body: some View { NavigationSplitView { List { ForEach(books) { book in NavigationLink { Text("\(book.title)") Text(book.pages?.debugDescription ?? "pages is nil") } label: { Text("\(book.title)") Spacer() Text("\(book.pages?.count.description ?? "pages is nil" )") } } } HStack { Button("Clear Data") { clearData() } Button("Add Book") { addBook() } } .navigationSplitViewColumnWidth(min: 180, ideal: 200) } detail: { Text("Select an item") } } private func clearData() { for book in books { modelContext.delete(book) } try? modelContext.save() } private func addBook() { let newBook = Book(title: "A New Book") modelContext.insert(newBook) } } @main struct BookPageApp: App { var sharedModelContainer: ModelContainer = { let schema = Schema([Book.self, Page.self]) let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false) do { return try ModelContainer(for: schema, configurations: [modelConfiguration]) } catch { fatalError("Could not create ModelContainer: \(error)") } }() var body: some Scene { WindowGroup { ContentView() } .modelContainer(sharedModelContainer) } } #Preview { ContentView() .modelContainer(for: Book.self, inMemory: true) }

"No records found" If I create a new record on the console, I can copy the record name. I can then query for recordName and get that individual record back. BUT no other queries work. I cannot query all records. I cannot query by individual property. Just returns "no records found" Seems like my indexes got messed up. Is there a way to reset indexes on prod? This is on a coredata.cloudkit managed zone.

Hi there, I got two models here: Two Models, with Many-To-Many Relationship @Model final class PresetParams: Identifiable { @Attribute(.unique) var id: UUID = UUID() var positionX: Float = 0.0 var positionY: Float = 0.0 var positionZ: Float = 0.0 var volume: Float = 1.0 @Relationship(deleteRule: .nullify, inverse: \Preset.presetAudioParams) var preset = [Preset]() init(position: SIMD3<Float>, volume: Float) { self.positionX = position.x self.positionY = position.y self.positionZ = position.z self.volume = volume self.preset = [] } var position: SIMD3<Float> { get { return SIMD3<Float>(x: positionX, y: positionY, z: positionZ) } set { positionX = newValue.x positionY = newValue.y positionZ = newValue.z } } } @Model final class Preset: Identifiable { @Attribute(.unique) var id: UUID = UUID() var presetName: String var presetDesc: String? var presetAudioParams = [PresetParams]() // Many-To-Many Relationship. init(presetName: String, presetDesc: String? = nil) { self.presetName = presetName self.presetDesc = presetDesc self.presetAudioParams = [] } } To be honest, I don't fully understand how the @Relationship thing works properly in a Many-To-Many relationship situation. Some tutorials suggest that it's required on the "One" side of an One-To-Many Relationship, while the "Many" side doesn't need it. And then there is an ObservableObject called "ModelActors" to manage all ModelActors, ModelContainer, etc. ModelActors, ModelContainer... class ModelActors: ObservableObject { static let shared: ModelActors = ModelActors() let sharedModelContainer: ModelContainer private init() { var schema = Schema([ // ... Preset.self, PresetParams.self, // ... ]) do { sharedModelContainer = try ModelContainer(for: schema, migrationPlan: MigrationPlan.self) } catch { fatalError("Could not create ModelContainer: \(error.localizedDescription)") } } } And there is a migrationPlan: MigrationPlan // MARK: V102 // typealias ... // MARK: V101 typealias Preset = AppSchemaV101.Preset typealias PresetParams = AppSchemaV101.PresetParams // MARK: V100 // typealias ... enum MigrationPlan: SchemaMigrationPlan { static var schemas: [VersionedSchema.Type] { [ AppSchemaV100.self, AppSchemaV101.self, AppSchemaV102.self, ] } static var stages: [MigrationStage] { [AppMigrateV100toV101, AppMigrateV101toV102] } static let AppMigrateV100toV101 = MigrationStage.lightweight(fromVersion: AppSchemaV100.self, toVersion: AppSchemaV101.self) static let AppMigrateV101toV102 = MigrationStage.lightweight(fromVersion: AppSchemaV101.self, toVersion: AppSchemaV102.self) } // MARK: Here is the AppSchemaV101 enum AppSchemaV101: VersionedSchema { static var versionIdentifier: Schema.Version = Schema.Version(1, 0, 1) static var models: [any PersistentModel.Type] { return [ // ... Preset.self, PresetParams.self ] } } Fails on iOS 18.3.x: "Failed to fulfill link PendingRelationshipLink" So I expected the SwiftData subsystem to work correctly with version control. A good news is that on iOS 18.1 it does work. But it fails on iOS 18.3.x with a fatal Error: "SwiftData/SchemaCoreData.swift:581: Fatal error: Failed to fulfill link PendingRelationshipLink(relationshipDescription: (<NSRelationshipDescription: 0x30377fe80>), name preset, isOptional 0, isTransient 0, entity PresetParams, renamingIdentifier preset, validation predicates (), warnings (), versionHashModifier (null)userInfo {}, destination entity Preset, inverseRelationship (null), minCount 0, maxCount 0, isOrdered 0, deleteRule 1, destinationEntityName: "Preset", inverseRelationshipName: Optional("presetAudioParams")), couldn't find inverse relationship 'Preset.presetAudioParams' in model" Fails on iOS 17.5: Another Error I tested it on iOS 17.5 and found another issue: Accessing or mutating the "PresetAudioParams" property causes the SwiftData Macro Codes to crash, affecting both Getter and Setter. It fails with an error: "EXC_BREAKPOINT (code=1, subcode=0x1cc1698ec)" Tweaking the @Relationship marker and ModelContainer settings didn't fix the problem.

I have some code which handles doing some computation on a background thread before updating Core Data NSManagedObjects by using the NSManagedObjectContext.perform functions. This code is covered in Sendable warnings in Xcode 26 (beta 6) because my NSManagedObject subclasses (autogenerated) are non-Sendable and NSManagedObjectContext.perform function takes a Sendable closure. But I can't really figure out what I should be doing. I realize this pattern is non-ideal for Swift concurrency, but it's what Core Data demands AFAIK. How do I deal with this? let moc = object.managedObjectContext! try await moc.perform { object.completed = true // Capture of 'object' with non-Sendable type 'MySpecialObject' in a '@Sendable' closure try moc.save() } Thanks in advance for your help!

I can't access the CloudKit Console. It started to be unresponsive for hours today. It looks like sync'ing is still working, but I would like to reset the environment during my development! Is it possible to control CloudKit Console using the command line?

Hi everyone In the last 24 hours, I’ve been running into some issues with the CloudKit console. Most of the time, I‘ll get an error stating an error has caused this web page to stop working correctly. Reloading doesn’t fix the issue, nor does using different browsers: Today I’ve got another error, something along the lines of the Console not being able to fetch the teams I’m assigned to and an XHF error pop-up. Has anyone encountered the same issues? After trying multiple times, I’m able to reach my database but it’s a bit frustrating as it’s very unreliable this way. Thanks for your feedback! Dave

If Cloudkit is enabled, SwiftData @Query operation hangs when the View scenePhase becomes active. Seems like the more @Query calls you have, the more it hangs. This has been first documented some time ago, but in typical Apple style, it has not been addressed or even commented on. https://developer.apple.com/forums/thread/761434

If I use <FetchRequest.returnsDistinctResults> with unique "identifier" property, and there happened to be multiple NSManagedObjects in Core Data that contains the same "identifier", does the FetchRequest retrieve the latest modified/created object? Is there a way to define the <FetchRequest.returnsDistinctResults> logic to be based on another property (e.g. "creationDate" / "modifiedDate") and the ascension order?