I have an image field on a Core Data entity with "Allows External Storage" enabled. When I delete a record, the external binary data file remains on disk. How can I ensure that all externally stored data is deleted along with the record?
iCloud & Data
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I have an iOS app (1Address) which allows users to share their address with family and friends using CloudKit Sharing.
Users share their address record (CKRecord) via a share link/url which when tapped allows the receiving user to accept the share and have a persistent view into the sharing user's address record (CKShare).
However, most users when they recieve a sharing link do not have the app installed yet, and so when a new receiving user taps the share link, it prompts them to download the app from the app store.
After the new user downloads the app from the app store and opens the app, my understanding is that the system (iOS) will/should then vend to my app the previously tapped cloudKitShareMetadata (or share url), however, this metadata is not being vended by the system. This forces the user to re-tap the share link and leads to some users thinking the app doesn't work or not completing the sharing / onboarding flow.
Is there a workaround or solve for this that doesn't require the user to tap the share link a second time?
In my scene delegate I am implementing:
func scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {...}
And also
func scene(_ scene: UIScene, continue userActivity: NSUserActivity) {...}
And also:
func windowScene(_ windowScene: UIWindowScene, userDidAcceptCloudKitShareWith cloudKitShareMetadata: CKShare.Metadata) {...}
And:
func scene(_ scene: UIScene, openURLContexts URLContexts: Set<UIOpenURLContext>) {...}
Unfortunately, none of these are called or passed metadata on the initial app run after install. Only after the user goes back and taps a link again can they accept the share.
This documentation: https://developer.apple.com/documentation/cloudkit/ckshare says that adding the CKSharingSupported key to your app's Info.plist file allows the system to launch your app when a user taps or clicks a share URL, but it does not clarify what should happen if your app is being installed for the first time.
This seems to imply that the system is holding onto the share metadata and/or url, but for some reason it is not being vended to the app on first run.
Open to any ideas here for how to fix and I also filed feedback: FB20934189.
Every time I insert a subclass (MYShapeLayer) into the model context, the app crashes with an error:
DesignerPlayground crashed due to fatalError in BackingData.swift at line 908. Never access a full future backing data - PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(backing: SwiftData.PersistentIdentifier.PersistentIdentifierBacking.managedObjectID(0xb2dbc55f3f4c57f2 <x-coredata://B1E3206B-40DE-4185-BC65-4540B4705B40/MYShapeLayer/p1>))) with Optional(A6CA4F89-107F-4A66-BC49-DD7DAC689F77)
struct ContentView: View {
@Environment(\.modelContext) private var modelContext
@Query private var designs: [MYDesign]
var layers: [MYLayer] {
designs.first?.layers ?? []
}
var body: some View {
NavigationStack {
List {
ForEach(layers) { layer in
Text(layer.description)
}
}
.onAppear {
let design = MYDesign(title: "My Design")
modelContext.insert(design)
try? modelContext.save()
}
.toolbar {
Menu("Add", systemImage: "plus") {
Button(action: addTextLayer) {
Text("Add Text Layer")
}
Button(action: addShapeLayer) {
Text("Add Shape Layer")
}
}
}
}
}
private func addTextLayer() {
if let design = designs.first {
let newLayer = MYLayer(order: layers.count, kind: .text)
newLayer.design = design
modelContext.insert(newLayer)
try? modelContext.save()
}
}
private func addShapeLayer() {
if let design = designs.first {
let newLayer = MYShapeLayer(shapeName: "Ellipse", order: layers.count)
newLayer.design = design
modelContext.insert(newLayer)
try? modelContext.save()
}
}
}
#Preview {
ContentView()
.modelContainer(for: [MYDesign.self, MYLayer.self, MYShapeLayer.self], inMemory: true)
}
@Model
final class MYDesign {
var title: String = ""
@Relationship(deleteRule: .cascade, inverse: \MYLayer.design)
var layers: [MYLayer] = []
init(title: String = "") {
self.title = title
}
}
@available(iOS 26.0, macOS 26.0, *)
@Model
class MYLayer {
var design: MYDesign!
var order: Int = 0
var title: String = ""
init(order: Int = 0, title: String = "New Layer") {
self.order = order
self.title = title
}
}
@available(iOS 26.0, macOS 26.0, *)
@Model
class MYShapeLayer: MYLayer {
var shapeName: String = ""
init(shapeName: String, order: Int = 0) {
self.shapeName = shapeName
super.init(order: order)
}
}
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
}
}
Good morning everyone!
Today I have a question about using SwiftData with CloudKit and Widgets. I recently set up my project for SwiftData and CloudKit synchronization, but for some reason, I’m not able to give my Widget access to this data. CloudKit works perfectly fine for my main app, but the Widget only shows placeholder data(the placeholder data which were defined in the get functions as catch, this is sure).
I have set the CloudKit capability for my Widget extension and tried fetching data with the get-functions in the code below. I also ensured that the data model files are members of the Widget extension target and that the Widget extension uses the same CloudKit container as the main app.
I wondered if it is possible and reasonable to save a copy of my CloudKit data in an App Group container, but in that case, the information shown in the Widget are not always up-to-date, so a solution that fetches data directly from CloudKit would be better. Has anyone had experience with this case? I couldn’t find much information about this problem online.
In the code below, many parts have been deleted or altered because they are not relevant to the problem, as they don’t fetch data. The variables, functions, and data models in the code may sometimes have German names, but I hope you can still understand it.
Thanks for your help!
struct Provider: AppIntentTimelineProvider {
//[Placeholder and snapshot]
func timeline(for configuration: ConfigurationAppIntent, in context: Context) async -> Timeline<CleverEntry> {
let entry = await loadAllVariables()
return Timeline(entries: [entry], policy: .after(Date().addingTimeInterval(60 * 5)))
}
@MainActor
private func getExam() -> [PruefungM] {
//Old, local version
/*
guard let modelContainer = try? ModelContainer(for: PruefungM.self) else {
return []
}
let descriptor = FetchDescriptor<PruefungM>()
let PRF = try? modelContainer.mainContext.fetch(descriptor)
return PRF ?? []
*/
do {
let configuration = ModelConfiguration(cloudKitDatabase: .private("iCloud.my_bundle_id"))
let container = try ModelContainer(
for: PruefungM.self,
configurations: configuration
)
let descriptor = FetchDescriptor<PruefungM>()
return try container.mainContext.fetch(descriptor)
} catch {
print("❌ Error(CloudKit): \(error)")
return []
}
}
@MainActor
private func getHAF() -> [HausaufgabeM] {
do {
let configuration = ModelConfiguration(cloudKitDatabase: .private("iCloud.my_bundle_id"))
let container = try ModelContainer(
for: HausaufgabeM.self,
configurations: configuration
)
let descriptor = FetchDescriptor<HausaufgabeM>()
return try container.mainContext.fetch(descriptor)
} catch {
print("❌ Error (CloudKit): \(error)")
return []
}
}
@MainActor
private func loadAllVariables() -> CleverEntry {
print("Function started")
let HAF = getHAF()
let PRF = getExam()
//handling and returning the data
}
}
I have been using the basic NSPersistentContainer with 100k+ records for a while now with no issues. The database size can fluctuate a bit but on average it takes up about 22mb on device.
When I switch the container to NSPersistentCloudKitContainer, I see a massive increase in size to ~150mb initially. As the sync engine uploads records to iCloud it has ballooned to over 600mb on device. On top of that, the user's iCloud usage in settings reports that it takes up 1.7gb in the cloud.
I understand new tables are added and history tracking is enabled but the size increase seems a bit drastic. I'm not sure how we got from 22mb to 1.7gb with the exact same data.
A few other things that are important to note:
I import all the 100k+ records at once when testing the different containers. At the time of the initial import there is only 1 relation (an import group record) that all the records are attached to.
I save the background context only once after all the records and the import group have been made and added to the context.
After the initial import, some of these records may have a few new relations added to them over time. I suppose this could be causing some of the size increase, but its only about 20,000 records that are updated.
None of the records include files/ large binary data.
Most of the attributes are encrypted.
I'm syncing to the dev iCloud environment.
When I do make a change to a single attribute in a record, CloudKit reports that every attribute has been modified (not sure if this is normal or not )
Also, When syncing to a new device, the sync can take hours - days. I'm guessing it's having to sync both the new records and the changes, but it exponentially gets slower as more records are downloaded. The console will show syncing activity, but new records are being added at a slower rate as more records are added. After about 50k records, it grinds to a halt and while the console still shows sync activity, only about 100 records are added every hour.
All this to say i'm very confused where these issues are coming from. I'm sure its a combination of how i've setup my code and the vast record count, record history, etc.
If anyone has any ideas it would be much appreciated.
Experiencing a crash that is only reproducible on TestFlight or AppStore version of the app, note this does not happen when running from Xcode.
I've isolated the problem to sort argument being added to @Query that fetches a model that sorts based on inherited property.
To reproduce:
@Model
class SuperModel {
var createdAt: Date = .now
}
@available(macOS 26.0, *)
@Model
class SubModel: SuperModel {
}
@Query(sort: \SubModel.createdAt, animation: .default) private var models: [SubModel]
Hi everyone,
In the simple app below, I have a QueryView that has LazyVStack containing 100k TextField's that edit the item's content. The items are fetched with a @Query. On launch, the app will generate 100k items. Once created, when I press any of the TextField's , a severe hang happens, and every time I type a single character, it will cause another hang over and over again.
I looked at it in Instruments and it shows that the main thread is busy during the duration of the hang (2.31 seconds) updating QueryView. From the cause and effect graph, the update is caused by @Observable QueryController <Item>.(Bool).
Why does it take too long to recalculate the view, given that it's in a LazyVStack? (In other words, why is the hang duration directly proportional to the number of items?)
How to fix the performance of this app? I thought adding LazyVStack was all I need to handle the large dataset, but maybe I need to add a custom pagination with .fetchLimit on top of that? (I understand that ModelActor would be an alternative to @Query because it will make the database operations happen outside of the main thread which will fix this problem, but with that I will lose the automatic fetching of @Query.)
Thank you for the help!
import SwiftData
import SwiftUI
@main
struct QueryPerformanceApp: App {
var body: some Scene {
WindowGroup {
ContentView()
.modelContainer(for: [Item.self], inMemory: true)
}
}
}
@Model
final class Item {
var name: String
init(name: String) {
self.name = name
}
}
struct ItemDetail: View {
@Bindable var item: Item
var body: some View {
TextField("Name", text: $item.name)
}
}
struct QueryView: View {
@Query private var items: [Item]
var body: some View {
ScrollView {
LazyVStack {
ForEach(items) { item in
VStack {
ItemDetail(item: item)
}
}
}
}
}
}
struct ContentView: View {
let itemCount = 100_000
@Environment(\.modelContext) private var context
@State private var isLoading = true
var body: some View {
Group {
if isLoading {
VStack(spacing: 16) {
ProgressView()
Text("Generating \(itemCount) items...")
}
} else {
QueryView()
}
}
.task {
for i in 1...itemCount {
context.insert(Item(name: "Item \(i)"))
}
try? context.save()
isLoading = false
}
}
}
Apple WTF? What did you do to all my Apps? none of them work in iOS26.1 (all worked in 26.0).
XCode simply says:
CoreData: error: addPersistentStoreWithType:configuration:URL:options:error: returned error NSCocoaErrorDomain (134140) *
SwiftData is supposed to do all these automatically 🤷🏻
I am a novice developer, so please be kind. 😬
I am developing a simple macOS app backed with SwiftData and trying to set up iCloud sync so data syncs between two Macs running the app. I have added the iCloud capability, checked the CloudKit box, and selected an iCloud Container. Per suggestion of Paul Hudson, my model properties have either default values or are marked as optional, and the only relationship in my model is marked as optional.
@Model
final class Project {
// Stable identifier used for restoring selected project across launches.
var uuid: UUID?
var name: String = ""
var active: Bool = true
var created: Date = Foundation.Date(timeIntervalSince1970: 0)
var modified: Date = Foundation.Date(timeIntervalSince1970: 0)
// CloudKit requires to-many relationships to be optional in this schema.
@Relationship
var timeEntries: [TimeEntry]?
init(name: String, active: Bool = true, uuid: UUID? = UUID()) {
self.uuid = uuid
self.name = name
self.active = active
self.created = .now
self.modified = .now
self.timeEntries = []
}
@Model
final class TimeEntry {
// Core timing fields.
var start: Date = Foundation.Date(timeIntervalSince1970: 0)
var end: Date = Foundation.Date(timeIntervalSince1970: 0)
var codeRawValue: String?
var activitiesRawValue: String = ""
// Inverse relationship back to the owning project.
@Relationship(inverse: \Project.timeEntries)
var project: Project?
init(
start: Date = .now,
end: Date = .now.addingTimeInterval(60 * 60),
code: BillingCode? = nil,
activities: [ActivityType] = []
) {
self.start = start
self.end = end
self.codeRawValue = code?.rawValue
self.activitiesRawValue = Self.serializeActivities(activities)
}
I have set up the following in the AppDelegate for registering for remote notifications as well as some logging to console that the remote notification token was received and to be notified when when I am receiving remote notifications.
private final class TimeTrackerAppDelegate: NSObject, NSApplicationDelegate {
func applicationDidFinishLaunching(_ notification: Notification) {
print("📡 [Push] Registering for remote notifications")
NSApplication.shared.registerForRemoteNotifications()
}
func application(_ application: NSApplication, didRegisterForRemoteNotificationsWithDeviceToken deviceToken: Data) {
let tokenPreview = deviceToken.map { String(format: "%02x", $0) }.joined().prefix(16)
print("✅ [Push] Registered for remote notifications (token prefix: \(tokenPreview)...)")
}
func application(_ application: NSApplication, didFailToRegisterForRemoteNotificationsWithError error: Error) {
let nsError = error as NSError
print("❌ [Push] Failed to register for remote notifications: \(nsError.domain) (\(nsError.code)) \(nsError.localizedDescription)")
}
func application(_ application: NSApplication, didReceiveRemoteNotification userInfo: [String: Any]) {
print("📬 [Push] Received remote notification: \(userInfo)")
}
}
In testing, I run the same commit from Xcode on two different Macs logged into the same iCloud account.
My problem is that sync is not reliably working. Starting up the app on both Macs shows that the app successfully registered for remote notifications.
Sometimes, making an edit on Mac 1 is immediately reflected in Mac 2 UI along with didReceiveRemoteNotification message (all occurring while the Mac 2 app remains in foreground). Sometimes, the Mac 2 app needs to be backgrounded and re-foregrounded before the UI shows the updated data.
Sometimes, an edit on Mac 2 will show on Mac 1 only after re-foregrounded but not show any didReceiveRemoteNotification on the Mac 1 console.
Sometimes, an edit on Mac 2 will not show at all on Mac 1 even after re-foregrounding the app.
Sometimes, no edits sync between either Mac.
I had read about how a few years back, there was a bug in macOS where testing iCloud sync between Macs did not work while running from Xcode but would work in TestFlight. For me, running my app in TestFlight on both Macs has never been able to sync any edits between the Macs.
Any idea where I might be going wrong. It seems this should not be this hard and should not be failing so inconsistently. Wondering what I might be doing wrong here.
I'm developing a SwiftUI app using SwiftData and encountering a persistent issue:
Error Message:
Thread 1: Fatal error: Duplicate keys of type 'Bland' were found in a Dictionary.
This usually means either that the type violates Hashable's requirements, or that members of such a dictionary were mutated after insertion.
Details:
Occurrence: The error always occurs on the first launch of the app after installation. Specifically, it happens approximately 1 minute after the app starts.
Inconsistent Behavior: Despite no changes to the code or server data, the error occurs inconsistently.
Data Fetching Process:
I fetch data for entities (Bland, CrossZansu, and Trade) from the server using the following process:
Fetch Bland and CrossZansu entities via URLSession.
Insert or update these entities into the SwiftData context.
The fetched data is managed as follows:
func refleshBlandsData() async throws {
if let blandsOnServer = try await DataModel.shared.getBlands() {
await MainActor.run {
blandsOnServer.forEach { blandOnServer in
if let blandOnLocal = blandList.first(where: { $0.code == blandOnServer.code }) {
blandOnLocal.update(serverBland: blandOnServer)
} else {
modelContext.insert(blandOnServer.bland)
}
}
}
}
}
This is a simplified version of my StockListView. The blandList is a @Query property and dynamically retrieves data from SwiftData:
struct StockListView: View {
@Environment(\.modelContext) private var modelContext
@Query(sort: \Bland.sname) var blandList: [Bland]
@Query var users: [User]
@State private var isNotLoaded = true
@State private var isLoading = false
@State private var loadingErrorState = ""
var body: some View {
NavigationStack {
List {
ForEach(blandList, id: \.self) { bland in
NavigationLink(value: bland) {
Text(bland.sname)
}
}
}
.navigationTitle("Stock List")
.onAppear {
doIfFirst()
}
}
}
// This function handles data loading when the app launches for the first time
func doIfFirst() {
if isNotLoaded {
loadDataWithAnimationIfNotLoading()
isNotLoaded = false
}
}
// This function ensures data is loaded with an animation and avoids multiple triggers
func loadDataWithAnimationIfNotLoading() {
if !isLoading {
isLoading = true
Task {
do {
try await loadData()
} catch {
// Capture and store any errors during data loading
loadingErrorState = "Data load failed: \(error.localizedDescription)"
}
isLoading = false
}
}
}
// Fetch data from the server and insert it into the SwiftData model context
func loadData() async throws {
if let blandsOnServer = try await DataModel.shared.getBlands() {
for bland in blandsOnServer {
// Avoid inserting duplicate keys by checking for existing items in blandList
if !blandList.contains(where: { $0.code == bland.code }) {
modelContext.insert(bland.bland)
}
}
}
}
}
Entity Definitions:
Here are the main entities involved:
Bland:
@Model
class Bland: Identifiable {
@Attribute(.unique) var code: String
var sname: String
@Relationship(deleteRule: .cascade, inverse: \CrossZansu.bland)
var zansuList: [CrossZansu]
@Relationship(deleteRule: .cascade, inverse: \Trade.bland)
var trades: [Trade]
}
CrossZansu:
@Model
class CrossZansu: Equatable {
@Attribute(.unique) var id: String
var bland: Bland?
}
Trade:
@Model
class Trade {
@Relationship(deleteRule: .nullify)
var user: User?
var bland: Bland
}
User:
class User {
var id: UUID
@Relationship(deleteRule: .cascade, inverse: \Trade.user)
var trades: [Trade]
}
Observations:
Error Context: The error occurs after the data is fetched and inserted into SwiftData. This suggests an issue with Hashable requirements or duplicate keys being inserted unintentionally.
Concurrency Concerns: The fetch and update operations are performed in asynchronous tasks. Could this cause race conditions?
Questions:
Could this issue be related to how @Relationship and @Attribute(.unique) are managed in SwiftData?
What are potential pitfalls with Equatable implementations (e.g., in CrossZansu) when used in SwiftData entities?
Are there any recommended approaches for debugging "Duplicate keys" errors in SwiftData?
Additional Info:
Error Timing: The error occurs only during the app's first launch and consistently within the first minute.
Since publishing new record types to my CloudKit schema in production, a previously unchanged record type has stopped indexing new records.
While records of this type are successfully saved without errors, they are not returned in query results—they can only be accessed directly via their recordName. This issue occurs exclusively in the Production environment, both in the CloudKit Console and our iOS app.
The problem began on July 21, 2025, and continues to persist. The issue affects only new records of this specific record type; all other types are indexing and querying as expected.
The affected record's fields are properly configured with the appropriate index types (e.g., QUERYABLE) and have been not been modified prior to publishing the schema.
With this, are there any steps I should take to restore indexing functionality for this record type in Production? There have been new records inserted, and I would prefer to not have to reset the production database, if possible.
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
CloudKit
Cloud and Local Storage
CloudKit Dashboard
CloudKit Console
Hello,
In my iOS/SwiftUI/SwiftData app, I want the user to be able to hit [Cancel] from editing in a detail screen and return to the previous screen without changes being saved.
I believed that setting autosaveEnabled to false and/or calling .rollback would prevent changes from being saved, unless/until I call .save() when the user clicks [Save], but this does not seem to be correct.
I set modelContext.autosaveEnabled = false and I call modelContext.rollback() when the user hits [Cancel], but any changes they made are not rolled back, but saved even if I don’t call save().
I have tried setting autosaveEnabled to false when I create the ModelContainer on a @MainActor function when the App starts, and in the detail/edit screen’s .onAppear(). I can see that .rollback is being called when the [Cancel] button is tapped. In all cases, any changes the user made before hitting [Cancel] are saved.
The Developer Documentation on autosaveEnabled includes this:
“The default value is false. SwiftData automatically sets this property to true for the model container’s mainContext."
I am working on the mainContext, but it appears that setting autosaveEnabled to false has no effect no matter where in the code I set it.
If someone sees what I am doing wrong, I’d sure appreciate the input. If this description doesn’t explain the problem well enough, I’ll develop a minimal focused example.
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!
Hi all,
I’m encountering a consistent issue with SwiftData on watchOS when using CloudKit sync. After enabling:
let config = ModelConfiguration(schema: schema, cloudKitDatabase: .automatic)
…the app terminates ~30–60 seconds into a WKExtendedRuntimeSession. This happens specifically when:
Always-On Display is OFF
The iPhone is disconnected or in Airplane Mode
The app is running in a WKExtendedRuntimeSession (e.g., used for meditation tracking)
The Xcode logs show a warning:
Background Task ("CoreData: CloudKit Setup"), was created over 30 seconds ago. In applications running in the background, this creates a risk of termination.
It appears CloudKit sync setup is being triggered automatically and flagged by the system as an unmanaged long-running task, leading to termination.
Workaround:
Switching to:
let config = ModelConfiguration(schema: schema, cloudKitDatabase: .none)
…prevents the issue entirely — no background task warning, no crash.
Feedback ID submitted: FB17685611
Just wanted to check if others have seen this behavior or found alternative solutions. It seems like something Apple may need to address in SwiftData’s CloudKit handling on watchOS.
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
CloudKit
watchOS
Background Tasks
SwiftData
Hi everyone,
I’m running into a breaking issue with SwiftData automatic CloudKit syncing on iOS 26, and I'm trying to determine if this is a known regression or a new configuration requirement I missed.
The Setup: My setup is extremely standard; I am using the default configuration exactly as described in Apple's documentation here: https://developer.apple.com/documentation/swiftdata/syncing-model-data-across-a-persons-devices
The schema is very simple:
A single @Model class.
No relationships.
The Issue: Prior to iOS 26, this exact app was successfully syncing data between devices and to iCloud without issues. Immediately after the iOS 26 update, syncing stopped completely.
I haven't changed any code, but when I check the CloudKit Console, I am seeing some BAD_REQUEST errors during sync attempts.
Since I am using the default SwiftData sync (and not manual CKRecord handling), I’m not sure how my client code could be triggering a bad request unless the schema requirements have changed under the hood.
Questions:
Has anyone else seen increased BAD_REQUEST errors with SwiftData on iOS 26?
Are there new entitlements or strict schema requirements introduced in iOS 26 that might cause a previously valid model to be rejected by CloudKit?
Any pointers or confirmations would be appreciated. Thanks!
What have people's experience with converting locally stored app data to a more browser based accessible format? Firebase seems expensive, Subabase a bit more challenging, and CloudKit too restrictive.
If I have two consecutive calls like to perform(schedule: .immediate) like so:
func doSomething() async {
await self.perform(schedule: .immediate) {
// add log event 1 to data store
}
await self.perform(schedule: .immediate) {
// add log event 2 to data store
}
}
Can I be guaranteed that the block for log event 1 will happen after log event 2?
"log event" here is just an example, so please ignore things like storing date, etc.
Looking at the documentation here:
https://developer.apple.com/documentation/coredata/nsmanagedobjectcontext/perform(schedule:_:)
It's a little unclear whether any such guarantee is in place. However, given that the function returns the value from the block, it seems like I should be able to expect event 1 will always be executed before event 2 regardless of the schedule parameter?
I am using SwiftData with CloudKit to synchronize data across multiple devices, and I have encountered an issue: occasionally, abnormal sync behavior occurs between two devices (it does not happen 100% of the time—only some users have reported this problem). It seems as if synchronization between the two devices completely stops; no matter what operations are performed on one end, the other end shows no response.
After investigating, I suspect the issue might be caused by both devices simultaneously modifying the same field, which could lead to CloudKit's logic being unable to handle such conflicts and causing the sync to stall. Are there any methods to avoid or resolve this situation?
Of course, I’m not entirely sure if this is the root cause. Has anyone encountered a similar issue?
I have a Package.swift file that builds and runs from Xcode 15.2 without issue but fails to compile when built from the command line ("swift build"). The swift version is 6.0.3. I'm at wits end trying to diagnose this and would welcome any thoughts.
The error in question is
error: external macro implementation type 'SwiftDataMacros.PersistentModelMacro' could not be found for macro 'Model()'; plugin for module 'SwiftDataMacros' not found
The code associated with the module is very vanilla.
import Foundation
import SwiftData
@Model
public final class MyObject {
@Attribute(.unique) public var id:Int64
public var vertexID:Int64
public var updatedAt:Date
public var codeUSRA:Int32
init(id:Int64, vertexID:Int64, updatedAt:Date, codeUSRA:Int32) {
self.id = id
self.vertexID = vertexID
self.updatedAt = updatedAt
self.codeUSRA = codeUSRA
}
public static func create(id:Int64, vertexID:Int64, updatedAt:Date, codeUSRA:Int32) -> MyObject {
MyObject(id: id, vertexID: vertexID, updatedAt: updatedAt, codeUSRA: codeUSRA)
}
}
Thank you.