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'NSInvalidArgumentException', reason: 'Duplicate version checksums across stages detected.'
I have an iOS app using SwiftData with VersionedSchema. The schema is synchronized with an CloudKit container. I previously introduced some model properties that I have now removed, as they are no longer needed. This results in the current schema version being identical to one of the previous ones (except for its version number). This results in the following exception: 'NSInvalidArgumentException', reason: 'Duplicate version checksums across stages detected.' So it looks like we cannot have a newer schema version with an identical content to an older schema version. The intuitive way would be to re-add the old (identical) schema version to the end of the "schemas" list property in the SchemaMigrationPlan, in order to signal that it is the newest one, and to add a migration stage back to it, thus: public enum MySchemaMigrationPlan: SchemaMigrationPlan { public static var schemas: [any VersionedSchema.Type] { [ SchemaV100.self, SchemaV101.self, SchemaV100.self ] } public static var stages: [MigrationStage] { [ migrateV100toV101, migrateV101toV100 ] } However, I am not sure if this is the right way to go, as previously, as I wanted to write unit tests for schema migration and rollback, I tried defining an inverse for each migration stage, so that I could trigger a migration and a rollback from a unit test, which resulted in an exception saying that it is not supported to downgrade a VersionedSchema. I must admit that I solved the original problem by introducing a dummy model property that I will later remove. What would have been the correct approach?
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85
Jun ’25
SwiftData updates in the background are not merged in the main UI context
Hello, SwiftData is not working correctly with Swift Concurrency. And it’s sad after all this time. I personally found a regression. The attached code works perfectly fine on iOS 17.5 but doesn’t work correctly on iOS 18 or iOS 18.1. A model can be updated from the background (Task, Task.detached or ModelActor) and refreshes the UI, but as soon as the same item is updated from the View (fetched via a Query), the next background updates are not reflected anymore in the UI, the UI is not refreshed, the updates are not merged into the main. How to reproduce: Launch the app Tap the plus button in the navigation bar to create a new item Tap on the “Update from Task”, “Update from Detached Task”, “Update from ModelActor” many times Notice the time is updated Tap on the “Update from View” (once or many times) Notice the time is updated Tap again on “Update from Task”, “Update from Detached Task”, “Update from ModelActor” many times Notice that the time is not update anymore Am I doing something wrong? Or is this a bug in iOS 18/18.1? Many other posts talk about issues where updates from background thread are not merged into the main thread. I don’t know if they all are related but it would be nice to have 1/ bug fixed, meaning that if I update an item from a background, it’s reflected in the UI, and 2/ proper documentation on how to use SwiftData with Swift Concurrency (ModelActor). I don’t know if what I’m doing in my buttons is correct or not. Thanks, Axel import SwiftData import SwiftUI @main struct FB_SwiftData_BackgroundApp: App { var body: some Scene { WindowGroup { ContentView() .modelContainer(for: Item.self) } } } struct ContentView: View { @Environment(\.modelContext) private var modelContext @State private var simpleModelActor: SimpleModelActor! @Query private var items: [Item] var body: some View { NavigationView { VStack { if let firstItem: Item = items.first { Text(firstItem.timestamp, format: Date.FormatStyle(date: .omitted, time: .standard)) .font(.largeTitle) .fontWeight(.heavy) Button("Update from Task") { let modelContainer: ModelContainer = modelContext.container let itemID: Item.ID = firstItem.persistentModelID Task { let context: ModelContext = ModelContext(modelContainer) guard let itemInContext: Item = context.model(for: itemID) as? Item else { return } itemInContext.timestamp = Date.now.addingTimeInterval(.random(in: 0...2000)) try context.save() } } .buttonStyle(.bordered) Button("Update from Detached Task") { let container: ModelContainer = modelContext.container let itemID: Item.ID = firstItem.persistentModelID Task.detached { let context: ModelContext = ModelContext(container) guard let itemInContext: Item = context.model(for: itemID) as? Item else { return } itemInContext.timestamp = Date.now.addingTimeInterval(.random(in: 0...2000)) try context.save() } } .buttonStyle(.bordered) Button("Update from ModelActor") { let container: ModelContainer = modelContext.container let persistentModelID: Item.ID = firstItem.persistentModelID Task.detached { let actor: SimpleModelActor = SimpleModelActor(modelContainer: container) await actor.updateItem(identifier: persistentModelID) } } .buttonStyle(.bordered) Button("Update from ModelActor in State") { let container: ModelContainer = modelContext.container let persistentModelID: Item.ID = firstItem.persistentModelID Task.detached { let actor: SimpleModelActor = SimpleModelActor(modelContainer: container) await MainActor.run { simpleModelActor = actor } await actor.updateItem(identifier: persistentModelID) } } .buttonStyle(.bordered) Divider() .padding(.vertical) Button("Update from View") { firstItem.timestamp = Date.now.addingTimeInterval(.random(in: 0...2000)) } .buttonStyle(.bordered) } else { ContentUnavailableView( "No Data", systemImage: "slash.circle", // 􀕧 description: Text("Tap the plus button in the toolbar") ) } } .toolbar { ToolbarItem(placement: .primaryAction) { Button(action: addItem) { Label("Add Item", systemImage: "plus") } } } } } private func addItem() { modelContext.insert(Item(timestamp: Date.now)) try? modelContext.save() } } @ModelActor final actor SimpleModelActor { var context: String = "" func updateItem(identifier: Item.ID) { guard let item = self[identifier, as: Item.self] else { return } item.timestamp = Date.now.addingTimeInterval(.random(in: 0...2000)) try! modelContext.save() } } @Model final class Item: Identifiable { var timestamp: Date init(timestamp: Date) { self.timestamp = timestamp } }
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750
Apr ’25
iOS app transfer effect in app's documents
Hi, We are currently planning an app transfer between two developer accounts. We are concerned about files stored in the app's documents surviving the first update of the app released with the new developer account. Since app files in documents are part of the app's container, is it safe to assume that if the user just updates the app after the transfer, the files in documents would still be there? It is important for us to confirm this before we execute our plans Also, our app currently uses iCloud containers to save another set of files. Are these transferred with the app transfer or will the app lose access to these files? Are the files however accessible by users' by looking for them on their iCloud Drive? Thank you!
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354
Sep ’24
Sorting with Complex & Arbitrary Nested Models
I’m developing an app for inspections that allows users to develop their own template for inspections. Because of this, my data structure has become more than a little complex (see below). This structure does allow a great deal in flexibility, through, as users can add groups, rows, and individual fields as needed. For example, users can add a header group, then a row to the header with fields for the Building Number, Unit Number, & Inspection Date. However, I don’t have an efficient way to sort the inspections by the values in these fields. SwiftData sorting is keypath based, which won’t allow me to sort the inspections based on the values only in fields with specific labels. As an alternative, I can query for fields with a specific label and do a compactMap to the inspection. But this doesn’t scale well when working with potentially hundreds or thousands of inspections as compactMap takes a lot longer then the query takes. It also doesn’t work well if I want to filter inspections or sort using values in multiple user defined fields. Models below are greatly simplified to just get the point across. More than happy to provide some additional code if asked when I’m back at my laptop with the source code. (Typing this on my iPad at the moment) @Model final class Inspection { // init and other fields var groups: [Group]? } @Model final class Group { // init and other fields @Relationship(inverse: \Inspection.groups) var inspection: Inspection? var rows: [Row]? } @Model final class Row { // init and other fields @Relationship(inverse: \Group.rows) var group: Group? var fields: [Field]? } @Model final class Field { // init and other fields var label: String? var type: FieldType // enum, denoting what type of data this is storing var stringValue: String? var boolValue: Bool? var dateValue: Date? @Attribute(.externalStorage) var dataValue: Data? @Relationship(inverse: \Row.fields) var row: Row? }
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376
Sep ’24
Is iCloud sync working?
Hello, I tried to validate if my app was properly syncing to the cloud. To test this, I created some data in the app, and then deleted the app, and reinstalled. I was expecting the data to still exist but it isn't. Is this a valid test or is the data expected to be deleted when app is deleted?
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165
Mar ’25
Collaboration of iCloud Drive document with CloudKit-based live sync
In Apple Numbers and similar apps, a user can save a document to iCloud Drive, and collaborate with other users. From what I can gather, it seems to use two mechanisms: the document as a whole is synced via iCloud Drive, but when a collaboration is started, it seems to use CloudKit records to do live updates. I am working on a similar app, that saves documents to iCloud Drive (on Mac, iPad, and iPhone). Currently it only syncs via iCloud Drive, re-reading the entire (often large) document when a remote change occurs. This can lead to a delay of several seconds (up to a minute) for the document to be saved, synced to the server, synced from the server, and re-read. I'm working on adding a "live sync", i.e. the ability to see changes in as near to real-time as feasible, like in Apple's apps. The document as a whole will remain syncing via iCloud Drive. My thought is to add a CloudKit CKRecord-based sync when two or more users are collaborating on a document, recording only the diffs for quick updates. The app would no longer re-read the entire document when iCloud Drive updates it while in use, and would instead read the CloudKit records and apply those changes. This should be much faster. Is my understanding of how Apple does it correct? Does my proposed approach seem sensible? Has anyone else implemented something like this, with iCloud Drive-based documents and a CloudKit live sync? In terms of technologies, I see that Apple now has a Shared with You framework, with the ability to use a NSItemProvider to start the collaboration. Which raises the question, should I use the iCloud Drive document for the collaboration (as I do now), or the CloudKit CKShare diff? I think I'd have to use the document as a whole, both so it works with the Send Copy option, and so a user that doesn't have the document gets it when using Collaborate. Once the collaboration is underway, I'd want to start the CloudKit channel. So I guess I'd save the CKShare to the server, get its URL, and save that in the document, so another user can read that URL as part of their initial load of the document from iCloud Drive? Once two (or more) users have the document via iCloud Drive, and the CKShare via the embedded URL, I should be able to do further live-sync updates via CloudKit. If a user closes the document and re-opens it, they'd get the updates via iCloud Drive, so no need to apply any updates from before the document was opened. Does all this sound reasonable, or am I overlooking some gotcha? I'd appreciate any advice from people who have experience with this kind of syncing.
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529
Jan ’25
CKSyncEngine: Can Long-Offline Devices Miss CloudKit Change Notifications?
Problem Description: When a device (Device 2) stays offline for an extended period after a record is deleted from another synced device (Device 1) via CloudKit, is it possible for Device 2 to miss the deletion notification when it reconnects, even when using CKSyncEngine? This scenario raises questions about whether CKSyncEngine can reliably sync changes if CloudKit archives or purges metadata related to deletions during the offline period. Steps to Reproduce: At time t0: · Device 1 and Device 2 sync successfully via CKSyncEngine (shared record RecordA). Device 2 goes offline. On Device 1: · Delete RecordA; sync completes via CKSyncEngine. Wait for a duration potentially exceeding CloudKit’s change retention window (if such a window exists). Bring Device 2 back online. Observe synchronization: · Expected Behavior: CKSyncEngine removes RecordA from Device 2. · Observed Behavior: RecordA remains on Device 2. Key Questions: Under these conditions, can Device 2 permanently miss the deletion event due to CloudKit’s internal metadata management? Is there a documented retention policy for CloudKit’s change history, and how does CKSyncEngine handle scenarios where this history is truncated? What is the recommended pattern to ensure no events are missed, regardless of offline duration? Clarifications Needed: · If CloudKit does discard deletion metadata after a period, is this considered a framework limitation, or should developers implement additional safeguards? · Does CKSyncEngine log warnings or errors when it detects incomplete sync histories? Environment: · CKSyncEngine with SQLite · CloudKit Private Database · iOS/macOS latest versions Thank you for clarifying how CKSyncEngine is designed to handle this edge case!
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249
Feb ’25
[SwiftData] How to get the first 7 elements by using @Query?
Maybe I didn't find the relevant instructions. In my code, I only want to get the first 7 elements. At present, my code is as follows: @Query(sort:\Record.date, order: .reverse) private var records:[Record] But I wonder if once the number of records is large, will it affect the efficiency? In View, it is enough for me to count the first 7 elements in records. What should I do?
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790
Nov ’24
@Query with Set
How do I filter data using @Query with a Set of DateComponents? I successfully saved multiple dates using a MultiDatePicker in AddView.swift. In ListView.swift, I want to retrieve all records for the current or today’s date. There are hundreds of examples using @Query with strings and dates, but I haven’t found an example of @Query using a Set of DateComponents Nothing will compile and after hundreds and hundreds of attempts, my hair is turning gray. Please, please, please help me. For example, if the current date is Tuesday, March 4 205, then I want to retrieve both records. Since both records contain Tuesday, March 4, then retrieve both records. Sorting works fine because the order by clause uses period which is a Double. Unfortunately, my syntax is incorrect and I don’t know the correct predicate syntax for @Query and a Set of DateComponents. Class Planner.swift file import SwiftUI import SwiftData 
 @Model class Planner { //var id: UUID = UUID() var grade: Double = 4.0 var kumi: Double = 4.0 var period: Double = 1.0 var dates: Set<DateComponents> = [] init( grade: Double = 4.0, kumi: Double = 4.0, period: Double = 1.0, dates: Set<DateComponents> = [] ) { self.grade = grade self.kumi = kumi self.period = period self.dates = dates 
 } } @Query Model snippet of code does not work The compile error is to use a Set of DateComponents, not just DateComponents. @Query(filter: #Predicate<Planner> { $0.dates = DateComponents(calendar: Calendar.current, year: 2025, month: 3, day: 4)}, sort: [SortDescriptor(\Planner.period)]) var planner: [Planner] ListView.swift image EditView.swift for record #1 DB Browser for SQLlite: record #1 (March 6, 2025 and March 4, 2025) 
 
 [{"isLeapMonth":false,"year":2025,"day":6,"month":3,"calendar":{"identifier":"gregorian","minimumDaysInFirstWeek":1,"current":1,"locale":{"identifier":"en_JP","current":1},"firstWeekday":1,"timeZone":{"identifier":"Asia\/Tokyo"}},"era":1},{"month":3,"year":2025,"day":4,"isLeapMonth":false,"era":1,"calendar":{"locale":{"identifier":"en_JP","current":1},"timeZone":{"identifier":"Asia\/Tokyo"},"current":1,"identifier":"gregorian","firstWeekday":1,"minimumDaysInFirstWeek":1}}]
 EditView.swift for record #2 DB Browser for SQLlite: record #2 (March 3, 2025 and March 4, 2025) 
 [{"calendar":{"minimumDaysInFirstWeek":1,"locale":{"current":1,"identifier":"en_JP"},"timeZone":{"identifier":"Asia\/Tokyo"},"firstWeekday":1,"current":1,"identifier":"gregorian"},"month":3,"day":3,"isLeapMonth":false,"year":2025,"era":1},{"year":2025,"month":3,"era":1,"day":4,"isLeapMonth":false,"calendar":{"identifier":"gregorian","current":1,"firstWeekday":1,"minimumDaysInFirstWeek":1,"timeZone":{"identifier":"Asia\/Tokyo"},"locale":{"current":1,"identifier":"en_JP"}}}]
 
 Any help is greatly appreciated.
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73
Mar ’25
macOS 15.5 (Sequoia) – iCloud Drive Hydration/Sync Failures on M4 MBP
I’m seeing persistent issues with iCloud Drive hydration and Finder sync on a new M4 MacBook Pro running Sequoia 15.5 (24F74). The same folders hydrate correctly on other Macs (Intel and M1), but not on the M4. ✅ Tried: – killall bird – Safe Mode boot – Toggling iCloud Drive and System Settings > Apple ID – Isolating network, user profile, and running First Aid 🔍 Findings: – EtreCheck report shows consistent high CPU usage from bird with no resolution. – Console logs suggest bird is waiting on local metadata index. – No VPNs installed. No third-party sync tools active. I’ve sanitized and attached the EtreCheck report as text for reference (or can paste if needed). ❓ Questions: 1. Is this a known issue on M4 systems or Sequoia 15.5? 2. Could file system ownership have been impacted by command-line tools? 3. Is there a safe method to reset bird metadata or iCloud sync state locally? Any guidance from Apple or other developers would be appreciated. Thanks!
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118
Jun ’25
SwiftData ModelConfigurations always sync to iCloud if one of them has iCloud enabled
I'm facing a weird issue with SwiftData. I want to have one database that's local to the device and one that syncs to iCloud. In this example, LTRLink should be synced via iCloud while LTRMetadata should stay on-device only. I've it configured like the following: let schema = Schema([LTRLink.self, LTRMetadata.self]) let cloudkitConfiguration = ModelConfiguration("Remote", schema: schema, url: FileManager.remoteDatabaseFolderURL.appending(path: "Remote.sqlite"), cloudKitDatabase: .private("iCloud.com.xavimoll.abyss3")) let localConfiguration = ModelConfiguration("Local", schema: schema, url: FileManager.localDatabaseFolderURL.appending(path: "Local.sqlite"), cloudKitDatabase: .none) return try ModelContainer(for: schema, configurations: [cloudkitConfiguration, localConfiguration]) For some reason, when I create the iCloud schema, both models end up appearing as records on iCloud. I create the schema like this: let schema = Schema([LTRLink.self, LTRMetadata.self]) let cloudkitConfiguration = ModelConfiguration("Remote", schema: schema, url: FileManager.remoteDatabaseFolderURL.appending(path: "Remote.sqlite"), cloudKitDatabase: .private("iCloud.com.xavimoll.abyss3")) #if DEBUG // Needed to create the schema on iCloud try autoreleasepool { let desc = NSPersistentStoreDescription(url: cloudkitConfiguration.url) let opts = NSPersistentCloudKitContainerOptions(containerIdentifier: cloudkitConfiguration.cloudKitContainerIdentifier!) desc.cloudKitContainerOptions = opts desc.shouldAddStoreAsynchronously = false if let mom = NSManagedObjectModel.makeManagedObjectModel(for: [LTRLink.self]) { let container = NSPersistentCloudKitContainer(name: "Remote", managedObjectModel: mom) container.persistentStoreDescriptions = [desc] container.loadPersistentStores {_, err in if let err { fatalError(err.localizedDescription) } } try container.initializeCloudKitSchema() if let store = container.persistentStoreCoordinator.persistentStores.first { try container.persistentStoreCoordinator.remove(store) } } } #endif let localConfiguration = ModelConfiguration("Local", schema: schema, url: FileManager.localDatabaseFolderURL.appending(path: "Local.sqlite"), cloudKitDatabase: .none) return try ModelContainer(for: schema, configurations: [cloudkitConfiguration, localConfiguration]) The logic to initialize the CloudKit schema follows the documentation found here: https://developer.apple.com/documentation/swiftdata/syncing-model-data-across-a-persons-devices#Initialize-the-CloudKit-development-schema It looks like setting cloudKitDatabase: .none on the init for the ModelConfiguration doesn't do anything, and ends up being synced with iCloud either way. When I go to the iCloud console, I see the following: Does anyone know if there's any workaround that would allow me to have two databases where only one of them syncs to iCloud when using SwiftData?
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618
Oct ’24
Swift Data issue with a recursive model class
Dear Apple Developer Forum As the title suggests, I have an issue with Swift Data when I want to modify a property of a recursive model class instance. Please consider the following sample project: import SwiftUI import SwiftData @main struct ISSUEApp: App { var sharedModelContainer: ModelContainer = { let schema = Schema([ Item.self, ]) let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: true) do { return try ModelContainer(for: schema, configurations: [modelConfiguration]) } catch { fatalError("Could not create ModelContainer: \(error)") } }() var body: some Scene { WindowGroup { ContentView() } .modelContainer(sharedModelContainer) } } @Model final class Item { var name: String? var parent: Item? init(name: String?, parent: Item?) { self.name = name self.parent = parent } } struct ContentView: View { @Environment(\.modelContext) private var context @Query private var items: [Item] @State private var itemToMove: Item? @State private var count: Int = 0 @State private var presentMoveView: Bool = false var body: some View { NavigationStack() { List(items, id: \.id) {item in Button(action: { itemToMove = item }, label: { Text("Id: \(item.name ?? "ERROR") and my parent iD is \(item.parent?.name ?? "root")") .bold(itemToMove == item) .italic(itemToMove == item) }) } .sheet(isPresented: $presentMoveView, content: { MoveView(toMove: self.itemToMove!) }) .toolbar { ToolbarItem(placement: .navigationBarTrailing) { Button(action: { let i = Item(name: "\(count)", parent: nil) context.insert(i) try? context.save() count += 1 }, label: { Text("Add an item") }) } ToolbarItem(placement: .navigationBarLeading) { Button(action: { presentMoveView.toggle() }, label: { Text("Move selected item") }) } } } } } struct MoveView: View { @Environment(\.modelContext) private var modelContext @Environment(\.dismiss) private var dismiss @Query private var items: [Item] @Bindable var toMove: Item @State private var selectedFutureParent: Item? var body: some View { NavigationStack(){ List(items, id: \.id) {item in Button(action: { selectedFutureParent = item }, label: { Text("Id: \(item.name ?? "ERROR") and my parent iD is \(item.parent?.name ?? "root")") .bold(selectedFutureParent == item) .italic(selectedFutureParent == item) }) } .toolbar(){ ToolbarItem{ Button("Move", action: { toMove.parent = selectedFutureParent dismiss() }) } } } } } #Preview { ContentView() .modelContainer(for: Item.self, inMemory: true) } Please launch the preview of this app, add items (as many as you'd like), select one and click on the "Move selected item" button. Select the new parent of the item. As you may have noticed, both selected items (moved item and new parent) are modified, whereas only one equality is used. This issue seems to be independent from the @Bindable property wrapper. I tried many things, such as using index instead of direct elements; using local let constant for the parent but the constant is still modified (very weird...) Thank you in advance for your help ! Best regards
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974
Oct ’24
CloudKit Console: No Containers
Background: Our non-production App was using SwiftData locally. Yesterday we followed the documentation to enable CloudKit: https://developer.apple.com/documentation/cloudkit/enabling-cloudkit-in-your-app iCloud Works: Data is properly syncing via iCloud between 2 devices. Add on one shows on the other; delete on one deletes on the other. Today we logged into CloudKit Console for the first time; but there are no databases showing. We verified: Users and Roles: we have “Access to Cloud Managed… Certificates” Certificates, Identifiers & Profiles: our app has iCloud capabilities and is using our iCloud Container Signed into CloudKit Console with same developer ID as AppStoreConnect This is also the Apple ID of the iCloud account that has synced data from our app. In Xcode > Signing & Capabilities we are signed in as our Company team. Any guidance or tips to understanding how to what’s going on in CloudKit Console and gaining access to the database is appreciated!
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111
Jun ’25
Core Data modifications not saved in two of three tables
I'm a bit lost because of a problem I never experienced before: I create entries in 3 Core Data tables and link them. As long as the app is open, everything is fine, I can see the database entries in the three tables. Once the App is closed and restarted, however, the new entries in two of the three tables are gone. I use Core Data for data storage and DB Browser for SQLite for inspecting the database running in the Simulator. Here's the relevant function where all Core Data handling happens: /** Creates a new ComposedFoodItem from the ComposedFoodItemViewModel. Creates the related FoodItem and the Ingredients. Creates all relationships. - Parameter composedFoodItemVM: The source view model. - Returns: A Core Data ComposedFoodItem; nil if there are no Ingredients. */ static func create(from composedFoodItemVM: ComposedFoodItemViewModel, generateTypicalAmounts: Bool) -> ComposedFoodItem? { debugPrint(AppDelegate.persistentContainer.persistentStoreDescriptions) // The location of the .sqlite file let moc = AppDelegate.viewContext // Create new ComposedFoodItem (1) let cdComposedFoodItem = ComposedFoodItem(context: moc) // No existing composed food item, therefore create a new UUID cdComposedFoodItem.id = UUID() // Fill data cdComposedFoodItem.amount = Int64(composedFoodItemVM.amount) cdComposedFoodItem.numberOfPortions = Int16(composedFoodItemVM.numberOfPortions) // Create the related FoodItem (2) let cdFoodItem = FoodItem.create(from: composedFoodItemVM, generateTypicalAmounts: generateTypicalAmounts) // Relate both (3) cdComposedFoodItem.foodItem = cdFoodItem // Add cdComposedFoodItem to composedFoodItemVM composedFoodItemVM.cdComposedFoodItem = cdComposedFoodItem // Add new ingredients (4) if let cdIngredients = Ingredient.create(from: composedFoodItemVM) { cdComposedFoodItem.addToIngredients(NSSet(array: cdIngredients)) // Save new composed food item try? moc.save() // Return the ComposedFoodItem return cdComposedFoodItem } else { // There are no ingredients, therefore we delete it again and return nil moc.delete(cdComposedFoodItem) try? moc.save() return nil } } What the function does: Creates a new entry in table ComposedFoodItem Creates another new entry in another table FoodItem Relates both entries Creates another 1..n entries in a third table Ingredient and links these to the entry created in step 1 All this works fine, I can see all relations and entries in the database. Then I quit and restart the app. The entry created in step 2 is still there, but the entries created in steps 1 and 4 are gone, as well as the relationships (of course). My suspicion: I recently implemented a Core Data migration from Data Model version 1 ("EasyFPU") to version 2 ("EasyFPU 2"). In this migration, I have two custom migration policies for exactly the two tables, which are not stored. The migration policies are pretty simple (and identical for both tables): /** No Ingredient is created in the destination model, i.e., there will be no Ingredients */ override func createDestinationInstances(forSource sourceIngredient: NSManagedObject, in mapping: NSEntityMapping, manager: NSMigrationManager) throws { // Do nothing on purpose debugPrint("Not migrating Ingredient with ID: \((sourceIngredient as? Ingredient)?.id.uuidString ?? "unknown")") } And what I suspect is, that this migration policies are somehow called when restarting the app, but I have no idea why, because the migration has already happened before. If I set a breakpoint in the debugPrint line of the code snippet above, I actually never reach this breakpoint - as expected. Nevertheless are the two tables Ingredient and ComposedFoodItem empty after restart. My AppDelegate Core Data persistentContainer variable looks like this: lazy var persistentContainer: NSPersistentCloudKitContainer = { let container = NSPersistentCloudKitContainer(name: "EasyFPU") container.loadPersistentStores(completionHandler: { (storeDescription, error) in if let error = error as NSError? { fatalError("Unresolved error \(error), \(error.userInfo)") } }) return container }() I tried to replace "EasyFPU" with "EasyFPU 2", but this apparently is not the version, but the container name. Any idea? Thanks in advance!
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0
353
Sep ’24
[SwiftData] How to use @Query to get the first 7 elements in the list
Maybe I didn't find the relevant instructions. In my code, I only want to get the first 7 elements. At present, my code is as follows: @Query(sort:\Record.date, order: .reverse) private var records:[Record] But I wonder if once the number of records is large, will it affect the efficiency? In View, it is enough for me to count the first 7 elements in records. What should I do?
1
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416
Nov ’24
Querying modifiedTimestamp in CloudKit
I have a requirement to get all records changed after a certain date. I have set modifiedTimestamp as Queryable, but when I attempt to do any query at all using the following operators: > < >= <= no results are returned. I have confirmed there are records that should be returned. The only operator that works is == and !=. I have tried the following: NSPredicate(format: "modificationDate > %@", lastFetched as NSDate) NSPredicate(format: "___modTime > %@", lastFetched as NSDate)
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839
Oct ’24
Inquiry Regarding Data Migration Using Quick Start
I am currently developing an iOS app with a new feature that utilizes Quick Start for data migration between devices. We are testing this in a test environment using an app distributed via TestFlight. However, we are encountering an issue where the app installed on the pre-migration device (distributed via TestFlight) does not transfer to the post-migration device. Could this issue be related to the fact that the app was distributed via TestFlight? Is there any restriction where only apps released via the App Store can be migrated using Quick Start? We would appreciate it if you could provide some insights into the cause of this issue and any alternative testing methods.
1
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563
Oct ’24
Replacing Core Data with SwiftData
I have an app that uses Core Data. I'm switching to SwiftData but it looks like the sqlite files are stored in separate places in the application file directory so my SwiftData files aren't reading the CoreData store. I'm not sure why it's not reading from the same location. Is there something I'm missing? Here's an example of the paths that I see when I write information to the debug console: SwiftData Path: file:///Users/dougthiele/Library/Developer/CoreSimulator/Devices/52CE32F8-F6A9-4825-8027-994DBE47173C/data/Containers/Data/Application/63E9B61D-64B8-4D2D-A02C-3C306688F354/Documents/[Data File Name].sqlite Core Data Path: file:///Users/dougthiele/Library/Developer/CoreSimulator/Devices/52CE32F8-F6A9-4825-8027-994DBE47173C/data/Containers/Data/Application/96A5961B-54DD-43A9-A4C3-661B439D91AE/Documents/[Data File Name].sqlite
1
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885
Oct ’24
Proper way to use a ModelContext from a background thread in a document based app
What is the idiomatic way to use a ModelContext in a document based SwiftData app from a background thread? The relevant DocumentGroup initializers do not give us direct access to a ModelContainer, only to a ModelContext. Is it safe to take its modelContext.container and pass it around (for creating a ModelContext on it on a background thread) or to construct a ModelActor with it? Is it safe to e.g. put a ModelActor so created into the environment of the root view of the window and execute various async data operations on it in Tasks throughout the app, as long as these are dispatched from within the window whose root view's ModelContext was used for getting the ModelContainer?
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Feb ’25