Hi. I'm hoping someone might be able to help us with an issue that's been affecting our standalone watchOS app for some time now.
We've encountered consistent crashes on Apple Watch devices when the app enters the background while the device is offline (i.e., no Bluetooth and no Wi-Fi connection). Through extensive testing, we've isolated the problem to the use of NSPersistentCloudKitContainer. When we switch to NSPersistentContainer, the crashes no longer occur.
Interestingly, this issue only affects our watchOS app. The same CloudKit-based persistence setup works reliably on our iOS and macOS apps, even when offline. This leads us to believe the issue may be specific to how NSPersistentCloudKitContainer behaves on watchOS when the device is disconnected from the network.
We're targeting watchOS 10 and above. We're unsure if this is a misconfiguration on our end or a potential system-level issue, and we would greatly appreciate any insight or guidance.
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I have the following struct doing some simple tasks, running a network request and then saving items to Core Data.
Per Xcode 26's new default settings (onisolated(nonsending) & defaultIsolation set to MainActor), the struct and its functions run on the main actor, which works fine and I can even safely omit the context.perform call because of it, which is great.
struct DataHandler {
func importGames(withIDs ids: [Int]) async throws {
...
let context = PersistenceController.shared.container.viewContext
for game in games {
let newGame = GYGame(context: context)
newGame.id = UUID()
}
try context.save()
}
}
Now, I want to run this in a background thread to increase performance and responsiveness. So I followed this session (https://developer.apple.com/videos/play/wwdc2025/270) and believe the solution is to mark the struct as nonisolated and the function itself as @concurrent.
The function now works on a background thread, but I receive a crash: _dispatch_assert_queue_fail. This happens whether I wrap the Core Data calls with context.perform or not. Alongside that I get a few new warnings which I have no idea how to work around.
So, what am I doing wrong here? What's the correct way to solve this simple use case with Swift 6's new concurrency stuff and the default main actor isolation in Xcode 26?
Curiously enough, when setting onisolated(nonsending) to false & defaultIsolation to non isolating, mimicking the previous behavior, the function works without crashing.
nonisolated
struct DataHandler {
@concurrent
func importGames(withIDs ids: [Int]) async throws {
...
let context = await PersistenceController.shared.container.newBackgroundContext()
for game in games {
let newGame = GYGame(context: context)
newGame.id = UUID() // Main actor-isolated property 'id' can not be mutated from a nonisolated context; this is an error in the Swift 6 language mode
}
try context.save()
}
}
I am trying to add a custom JSON DataStore and DataStoreConfiguration for SwiftData. Apple kindly provided some sample code in the WWDC24 session, "Create a custom data store with SwiftData", and (once updated for API changes since WWDC) that works fine.
However, when I try to add a relationship between two classes, it fails. Has anyone successfully made a JSONDataStore with a relationship?
Here's my code; firstly the cleaned up code from the WWDC session:
import SwiftData
final class JSONStoreConfiguration: DataStoreConfiguration {
typealias Store = JSONStore
var name: String
var schema: Schema?
var fileURL: URL
init(name: String, schema: Schema? = nil, fileURL: URL) {
self.name = name
self.schema = schema
self.fileURL = fileURL
}
static func == (lhs: JSONStoreConfiguration, rhs: JSONStoreConfiguration) -> Bool {
return lhs.name == rhs.name
}
func hash(into hasher: inout Hasher) {
hasher.combine(name)
}
}
final class JSONStore: DataStore {
typealias Configuration = JSONStoreConfiguration
typealias Snapshot = DefaultSnapshot
var configuration: JSONStoreConfiguration
var name: String
var schema: Schema
var identifier: String
init(_ configuration: JSONStoreConfiguration, migrationPlan: (any SchemaMigrationPlan.Type)?) throws {
self.configuration = configuration
self.name = configuration.name
self.schema = configuration.schema!
self.identifier = configuration.fileURL.lastPathComponent
}
func save(_ request: DataStoreSaveChangesRequest<DefaultSnapshot>) throws -> DataStoreSaveChangesResult<DefaultSnapshot> {
var remappedIdentifiers = [PersistentIdentifier: PersistentIdentifier]()
var serializedData = try read()
for snapshot in request.inserted {
let permanentIdentifier = try PersistentIdentifier.identifier(for: identifier,
entityName: snapshot.persistentIdentifier.entityName,
primaryKey: UUID())
let permanentSnapshot = snapshot.copy(persistentIdentifier: permanentIdentifier)
serializedData[permanentIdentifier] = permanentSnapshot
remappedIdentifiers[snapshot.persistentIdentifier] = permanentIdentifier
}
for snapshot in request.updated {
serializedData[snapshot.persistentIdentifier] = snapshot
}
for snapshot in request.deleted {
serializedData[snapshot.persistentIdentifier] = nil
}
try write(serializedData)
return DataStoreSaveChangesResult<DefaultSnapshot>(for: self.identifier, remappedIdentifiers: remappedIdentifiers)
}
func fetch<T>(_ request: DataStoreFetchRequest<T>) throws -> DataStoreFetchResult<T, DefaultSnapshot> where T : PersistentModel {
if request.descriptor.predicate != nil {
throw DataStoreError.preferInMemoryFilter
} else if request.descriptor.sortBy.count > 0 {
throw DataStoreError.preferInMemorySort
}
let objs = try read()
let snapshots = objs.values.map({ $0 })
return DataStoreFetchResult(descriptor: request.descriptor, fetchedSnapshots: snapshots, relatedSnapshots: objs)
}
func read() throws -> [PersistentIdentifier : DefaultSnapshot] {
if FileManager.default.fileExists(atPath: configuration.fileURL.path(percentEncoded: false)) {
let decoder = JSONDecoder()
decoder.dateDecodingStrategy = .iso8601
let data = try decoder.decode([DefaultSnapshot].self, from: try Data(contentsOf: configuration.fileURL))
var result = [PersistentIdentifier: DefaultSnapshot]()
data.forEach { s in
result[s.persistentIdentifier] = s
}
return result
} else {
return [:]
}
}
func write(_ data: [PersistentIdentifier : DefaultSnapshot]) throws {
let encoder = JSONEncoder()
encoder.dateEncodingStrategy = .iso8601
encoder.outputFormatting = [.prettyPrinted, .sortedKeys]
let jsonData = try encoder.encode(data.values.map({ $0 }))
try jsonData.write(to: configuration.fileURL)
}
}
The data model classes:
import SwiftData
@Model
class Settings {
private(set) var version = 1
@Relationship(deleteRule: .cascade) var hack: Hack? = Hack()
init() {
}
}
@Model
class Hack {
var foo = "Foo"
var bar = 42
init() {
}
}
Container:
lazy var mainContainer: ModelContainer = {
do {
let url = // URL to file
let configuration = JSONStoreConfiguration(name: "Settings", schema: Schema([Settings.self, Hack.self]), fileURL: url)
return try ModelContainer(for: Settings.self, Hack.self, configurations: configuration)
}
catch {
fatalError("Container error: \(error.localizedDescription)")
}
}()
Load function, that saves a new Settings JSON file if there isn't an existing one:
@MainActor func loadSettings() {
let mainContext = mainContainer.mainContext
let descriptor = FetchDescriptor<Settings>()
let settingsArray = try? mainContext.fetch(descriptor)
print("\(settingsArray?.count ?? 0) settings found")
if let settingsArray, let settings = settingsArray.last {
print("Loaded")
} else {
let settings = Settings()
mainContext.insert(settings)
do {
try mainContext.save()
} catch {
print("Error saving settings: \(error)")
}
}
}
The save operation creates a JSON file, which while it isn't a format I would choose, is acceptable, though I notice that the "hack" property (the relationship) doesn't have the correct identifier.
When I run the app again to load the data, I get an error (that there wasn't room to include in this post).
Even if I change Apple's code to not assign a new identifier, so the relationship property and its pointee have the same identifier, it still doesn't load.
Am I doing something obviously wrong, or are relationships not supported in custom data stores?
I'm running into an undocumented error coming back from CloudKit operations.
Specifically, I'm attempting to save new records via CKModifyRecordsOperation. I'm receiving this error for each of the records in the perRecordSaveBlock callback:
<CKError 0x3018ac3c0: "Internal Error" (1/3001); "MMCSEngineCreate failed">
Is anyone else facing this error? It has been happening for several days and I'm finally getting around to reproduction with the Console app and logs. I have 16 records on my device locally that each one gets this error back.
FB16547732 - CloudKit: CKModifyRecordsOperation saving new records results in Error <CKError 0x3018ac1e0: "Internal Error" (1/3001); "MMCSEngineCreate failed">
I am trying out the new AttributedString binding with SwiftUI’s TextEditor in iOS26. I need to save this to a Core Data database. Core Data has no AttributedString type, so I set the type of the field to “Transformable”, give it a custom class of NSAttributedString, and set the transformer to NSSecureUnarchiveFromData
When I try to save, I first convert the Swift AttributedString to NSAttributedString, and then save the context. Unfortunately I get this error when saving the context, and the save isn't persisted:
CoreData: error: SQLCore dispatchRequest: exception handling request: <NSSQLSaveChangesRequestContext: 0x600003721140> , <shared NSSecureUnarchiveFromData transformer> threw while encoding a value. with userInfo of (null)
Here's the code that tries to save the attributed string:
struct AttributedDetailView: View {
@ObservedObject var item: Item
@State private var notesText = AttributedString()
var body: some View {
VStack {
TextEditor(text: $notesText)
.padding()
.onChange(of: notesText) {
item.attributedString = NSAttributedString(notesText)
}
}
.onAppear {
if let nsattributed = item.attributedString {
notesText = AttributedString(nsattributed)
} else {
notesText = ""
}
}
.task {
item.attributedString = NSAttributedString(notesText)
do {
try item.managedObjectContext?.save()
} catch {
print("core data save error = \(error)")
}
}
}
}
This is the attribute setup in the Core Data model editor:
Is there a workaround for this?
I filed FB17943846 if someone can take a look.
Thanks.
My use case is the following:
Every user of my app can create as an owner a set of items.
These items are private until the owner invites other users to share all of them as participant.
The participants can modify the shared items and/or add other items.
So, sharing is not done related to individual items, but to all items of an owner.
I want to use CoreData & CloudKit to have local copies of private and shared items.
To my understanding, CoreData & CloudKit puts all mirrored items in a special zone „com.apple.coredata.cloudkit.zone“.
So, this zone should be shared, i.e. all items in it.
In the video it is said that NSPersistentCloudKitContainer uses Record Zone Sharing optionally in contrast to hierarchically record sharing using a root record.
But how is this done?
Maybe I can declare zone „com.apple.coredata.cloudkit.zone“ as a shared zone?
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
Cloud and Local Storage
UI Frameworks
wwdc21-10015
I have an Apple app that uses SwiftData and icloud to sync the App's data across users' devices. Everything is working well. However, I am facing the following issue:
SwiftData does not support public sharing of the object graph with other users via iCloud. How can I overcome this limitation without stopping using SwiftData?
Thanks in advance!
Hi,
I’m working on a macOS app that includes a file browser component. And I’m trying to match Finder’s behavior for color tags and folder icons.
For local files/folders everything works fine:
Tag color key returns the expected label number via
NSColor * labelColor = nil;
[fileURL getResourceValue:&labelColor forKey:NSURLLabelColorKey error:nil];
NSNumber * labelKey = nil;
[fileURL getResourceValue:&labelKey forKey:NSURLLabelNumberKey error:nil];
QLThumbnailGenerator obtains the expected colored folder icon (including emoji/symbol overlay if set) via
QLThumbnailGenerationRequest * request =
[[QLThumbnailGenerationRequest alloc] initWithFileAtURL:fileURL
size:iconSize
scale:scaleFactor
representationTypes:QLThumbnailGenerationRequestRepresentationTypeIcon];
request.iconMode = YES;
[[QLThumbnailGenerator sharedGenerator] generateBestRepresentationForRequest:request
completionHandler:^(QLThumbnailRepresentation * _Nullable thumbnail, NSError * _Nullable error) {
if (thumbnail != nil && error == nil)
{
NSImage * thumbnailImage = [thumbnail NSImage];
// ...
}
}];
However, for items on iCloud Drive (whether currently downloaded locally or only stored in the cloud), the same code always produces gray colors, while Finder shows everything correctly:
NSURLLabelNumberKey always returns 1 (gray) for items with color tags, and 0 for non-tagged.
Folder icons returned via QLThumbnailGenerator are gray, no emoji/symbol overlays.
Reading tag data from xattr gives values like “Green\1” (tag name matches, but numeric value is still "Gray").
Also, if I move a correctly-tagged local item into iCloud Drive, it immediately becomes gray in my app (Finder still shows the correct colors).
Question:
What is the supported way to retrieve Finder tag colors and the correct folder icon appearance (color + overlays) for items in iCloud Drive, so that the result matches Finder?
I am on macOS Tahoe 26.2/26.3, Xcode 26.2 (17C52).
If you need any additional details, please let me know.
Thanks!
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
Files and Storage
QuickLook Thumbnailing
iCloud Drive
I'm a first time developer for Swift, (getting on a bit!) but after programming in VB back in the late 90s I wanted to write an app for iPhone. I think I might have gone about it the wrong way, but I've got an app that works great on my iPhone or works great on my iPad. It saves the data persistently on device, but, no matter how much I try, what I read and even resorting to AI (ChatGPT & Gemini) I still can't get it to save the data on iCloud to synchronise between the two and work across the devices. I think it must be something pretty fundamental I'm doing (or more likely not doing) that is causing the issue.
I'm setting up my signing and capabilities as per the available instructions but I always get a fatal error. I think it might be something to do with making fields optional, but at this point I'm second guessing myself and feeling a complete failure. Any advice or pointers would be really gratefully appreciated. I like my app and would like eventually to get it on the App Store but at this point in time I feel it should be on the failed projects heap!
I've even tried a new Xcode project for iOS and asking it to use SwiftData and CloudKit - the default project should work - right? But it absolutely doesn't for me. Please send help!!
Hello Apple Team,
We’re building a CloudKit-enabled Core Data app and would like clarification on the behavior and performance characteristics of Binary Data attributes with “Allows External Storage” enabled when used with NSPersistentCloudKitContainer.
Initially, we tried storing image files manually on disk and only saving the metadata (file URLs, dimensions, etc.) in Core Data. While this approach reduced the size of the Core Data store, it introduced instability after app updates and broke sync between devices. We would prefer to use the official Apple-recommended method and have Core Data manage image storage and CloudKit syncing natively.
Specifically, we’d appreciate guidance on the following:
When a Binary Data attribute is marked as “Allows External Storage”, large image files are stored as separate files on device rather than inline in the SQLite store.
How effective is this mechanism in keeping the Core Data store size small on device?
Are there any recommended size thresholds or known limits for how many externally stored blobs can safely be managed this way?
How are these externally stored files handled during CloudKit sync?
Does each externally stored Binary Data attribute get mirrored to CloudKit as a CKAsset?
Does external storage reduce the sync payload size or network usage, or is the full binary data still uploaded/downloaded as part of the CKAsset?
Are there any bandwidth implications for users syncing via their private CloudKit database, versus developer costs in the public CloudKit database?
Is there any difference in CloudKit or Core Data behavior when a Binary Data attribute is managed this way versus manually storing image URLs and handling the file separately on disk?
Our goal is to store user-generated images efficiently and safely sync them via CloudKit, without incurring excessive local database bloat or CloudKit network overhead.
Any detailed guidance or internal performance considerations would be greatly appreciated.
Thank you,
Paul Barry
Founder & Lead Developer — Boat Buddy / Vessel Buddy iOS App
Archipelago Environmental Solutions Inc.
I am running into some issues when trying to destroy CoreData persistentStores. When a user logs out of my app, I want to completely reset CoreData and delete any existing data. My code to reset CoreData looks like this:
let coordinator = self.persistentContainer.persistentStoreCoordinator
self.persistentContainer.viewContext.reset()
coordinator.persistentStores.forEach { store in
guard let url = store.url else { return }
do {
try coordinator.destroyPersistentStore(at: url, type: .sqlite)
_ = try coordinator.addPersistentStore(ofType: NSSQLiteStoreType, configurationName: nil, at: url)
} catch {
print(error)
}
}
However, my app is crashing with
Object 0xb2b5cc80445813de <x-coredata://BDB999D4-49A4-4CB3-AC3A-666AD60BEFC6/AccountEntity/p5> persistent store is not reachable from this NSManagedObjectContext's coordinator
It seems this is related to the SwiftUI @FetchRequest wrappers. If I do not open the views where I am using @FetchRequest, the logout goes smoothly. Otherwise, I get the crash above.
Has anyone run into anything similar? Is there something else I need to do to get the underlying FRC to release its references to those entities? I was under the impression that calling reset() on the managed object context would be enough to remove those items from memory and get the destroying of the persistent store to go smoothly.
Alternately, is there another/better way I should be destroying the DB?
Any advice or related observations would be greatly appreciated. Thank you!
Hello,
My app has had CloudKit enabled for a while, but it's not working. I get the error "Invalid bundle ID for container".
Configure CloudKit in your project from TN3164 suggests changing to a new container. I tried changing to a new container, but this leads to data loss.
The article recommends:
"If your CloudKit container is already used in the production environment and switching to a new container leads to data loss, consider filing a feedback report with the following information to request manually associating your CloudKit container with your app ID."
Where can I request this manual association? Is there anything else I can do?
Thank you for your time and assistance. I’d appreciate a prompt resolution, as this issue is blocking our update. Looking forward to guidance.
Hi, I work on a financial app in Brazil and since Beta 1 we're getting several crashes. We already opened a code level support and a few feedback issues, but haven't got any updates on that yet.
We were able to resolve some crashes changing some of our implementation but we aren't able to understand what might be happening with this last one.
This is the log we got on console:
erro 11:55:41.805875-0300 MyApp CoreData: error: Failed to load NSManagedObjectModel with URL 'file:///private/var/containers/Bundle/Application/0B9F47D9-9B83-4CFF-8202-3718097C92AE/MyApp.app/ServerDrivenModel.momd/'
We double checked and the momd is inside the bundle. The same app works on any other iOS version and if we build using Xcode directly (without archiving and installing on an iOS26 device) it works as expected.
Have anyone else faced a similar error? Any tips or advice on how we can try to solve that?
Hey all,
This is my first app with Swift, and first app using CloudKit / iCloud - although I have launched other iOS app successfully.
When I created the app, I selected "none" for storage
my bundle identifier looks like this: io.mysite.appname
I have the iCloud capability added, with CloudKit checked, and the container also checked that looks like this: iCloud.io.mysite.appname
Push Notificaitons capability is also added, but there is no configuration.
I have tried automatically managed signing, as well as a manually created provisioning profile..
Every time I build the app onto my device - when I check it out in settings, icloud is not listed. When I go through iCloud into icloud drive, the app is also not listed.
I have cleaned the build many times, deleted and reinstalled the app on my phone many times. I am definitely logged into iCloud etc.
Obviously I have spent plenty of times trying to debug with various LLMs, but we all seem to be at a loss for what I'm missing or doing wrong.
Would love any tips or pointers I may be missing, thank you!
Topic:
App & System Services
SubTopic:
iCloud & Data
I'm running a project with these settings:
Default Actor Isolation: MainActor
Approachable Concurrency: Yes
Strict Concurrency Checking: Complete (this issue does not appear on the other two modes)
I receive a warning for this very simple use case. Can I actually fix anything about this or is this a case of Core Data not being entirely ready for this?
In reference to this, there was a workaround listed in the release notes of iOS 26 beta 5 (https://forums.swift.org/t/defaultisolation-mainactor-and-core-data-background-tasks/80569/22). Does this still apply as the only fix for this?
This is a simplified sample meant to run on a background context. The issue obviously goes away if this function would just run on the MainActor, then I can remove the perform block entirely.
class DataHandler {
func createItem() async {
let context = ...
await context.perform {
let newGame = Item(context: context)
/// Main actor-isolated property 'timestamp' can not be mutated from a Sendable closure
newGame.timestamp = Date.now
// ...
}
}
}
The complete use case would be more like this:
nonisolated
struct DataHandler {
@concurrent
func saveItem() async throws {
let context = await PersistenceController.shared.container.newBackgroundContext()
try await context.perform {
let newGame = Item(context: context)
newGame.timestamp = Date.now
try context.save()
}
}
}
Hi,
I'm getting a very odd error log in my SwiftData setup for an iOS app. It is implemented to support schema migration. When starting the app, it simply prints the following log twice (seems to be dependent on how many migration steps, I have two steps in my sample code):
CoreData: error: Attempting to retrieve an NSManagedObjectModel version checksum while the model is still editable. This may result in an unstable verison checksum. Add model to NSPersistentStoreCoordinator and try again.
(Yes there is a mistyped word "verison", this is exactly the log)
The code actually fully works. But I have neither CloudKit configured, nor is this app in Production yet. I'm still just developing.
Here is the setup and code to reproduce the issue.
Development mac version: macOS 15.5
XCode version: 16.4
iOS Simulator version: 18.5
Real iPhone version: 18.5
Project name: SwiftDataDebugApp
SwiftDataDebugApp.swift:
import SwiftUI
import SwiftData
@main
struct SwiftDataDebugApp: App {
var sharedModelContainer: ModelContainer = {
let schema = Schema([
Item.self,
])
let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false, allowsSave: true)
do {
return try ModelContainer(for: schema, migrationPlan: ModelMigraitonPlan.self, configurations: [modelConfiguration])
} catch {
fatalError("Could not create ModelContainer: \(error)")
}
}()
var body: some Scene {
WindowGroup {
ContentView()
}
.modelContainer(sharedModelContainer)
}
}
Item.swift:
import Foundation
import SwiftData
typealias Item = ModelSchemaV2_0_0.Item
enum ModelSchemaV1_0_0: VersionedSchema {
static var versionIdentifier = Schema.Version(1, 0, 0)
static var models: [any PersistentModel.Type] {
[Item.self]
}
@Model
final class Item {
var timestamp: Date
init(timestamp: Date) {
self.timestamp = timestamp
}
}
}
enum ModelSchemaV2_0_0: VersionedSchema {
static var versionIdentifier = Schema.Version(2, 0, 0)
static var models: [any PersistentModel.Type] {
[Item.self]
}
@Model
final class Item {
var timestamp: Date
var tags: [Tag] = []
init(timestamp: Date, tags: [Tag]) {
self.timestamp = timestamp
self.tags = tags
}
}
}
enum ModelMigraitonPlan: SchemaMigrationPlan {
static var schemas: [any VersionedSchema.Type] {
[ModelSchemaV1_0_0.self]
}
static var stages: [MigrationStage] {
[migrationV1_0_0toV2_0_0]
}
static let migrationV1_0_0toV2_0_0 = MigrationStage.custom(
fromVersion: ModelSchemaV1_0_0.self,
toVersion: ModelSchemaV2_0_0.self,
willMigrate: nil,
didMigrate: { context in
let items = try context.fetch(FetchDescriptor<ModelSchemaV2_0_0.Item>())
for item in items {
item.tags = Array(repeating: "abc", count: Int.random(in: 0...3)).map({ Tag(value: $0) })
}
try context.save()
}
)
}
Tag.swift:
import Foundation
struct Tag: Codable, Hashable, Comparable {
var value: String
init(value: String) {
self.value = value
}
static func < (lhs: Tag, rhs: Tag) -> Bool {
return lhs.value < rhs.value
}
static func == (lhs: Tag, rhs: Tag) -> Bool {
return lhs.value == rhs.value
}
func hash(into hasher: inout Hasher) {
hasher.combine(value)
}
}
ContentView.swift:
import SwiftUI
import SwiftData
struct ContentView: View {
@Environment(\.modelContext) private var modelContext
@Query private var items: [Item]
var body: some View {
VStack {
List {
ForEach(items) { item in
VStack(alignment: .leading) {
Text(item.timestamp, format: Date.FormatStyle(date: .numeric, time: .standard))
HStack {
ForEach(item.tags, id: \.hashValue) { tag in
Text("\(tag.value)")
}
}
}
}
.onDelete(perform: deleteItems)
}
Button("Add") {
addItem()
}
.padding(.top)
}
}
private func addItem() {
withAnimation {
let newItem = Item(timestamp: Date(), tags: [Tag(value: "Hi")])
modelContext.insert(newItem)
}
do {
try modelContext.save()
} catch {
print("Error saving add: \(error.localizedDescription)")
}
}
private func deleteItems(offsets: IndexSet) {
withAnimation {
for index in offsets {
modelContext.delete(items[index])
}
}
do {
try modelContext.save()
} catch {
print("Error saving delete: \(error.localizedDescription)")
}
}
}
#Preview {
ContentView()
.modelContainer(for: Item.self, inMemory: true)
}
I hope someone can help, couldn't find anything related to this log at all.
Using SwiftData and this is the simplest example I could boil down:
@Model
final class Item {
var timestamp: Date
var tag: Tag?
init(timestamp: Date) {
self.timestamp = timestamp
}
}
@Model
final class Tag {
var timestamp: Date
init(timestamp: Date) {
self.timestamp = timestamp
}
}
Notice Tag has no reference to Item.
So if I create a bunch of items and set their Tag. Later on I add the ability to delete a Tag. Since I haven't added inverse relationship Item now references a tag that no longer exists so so I get these types of errors:
SwiftData/BackingData.swift:875: Fatal error: This model instance was invalidated because its backing data could no longer be found the store. PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(url: x-coredata://EEC1D410-F87E-4F1F-B82D-8F2153A0B23C/Tag/p1), implementation: SwiftData.PersistentIdentifierImplementation)
I think I understand now that I just need to add the item reference to Tag and SwiftData will nullify all Item references to that tag when a Tag is deleted.
But, the damage is already done. How can I iterate through all Items that referenced a deleted tag and set them to nil or to a placeholder Tag? Or how can I catch that error and fix it when it comes up?
The crash doesn't occur when loading an Item, only when accessing item.tag?.timestamp, in fact, item.tag?.id is still ok and doesn't crash since it doesn't have to load the backing data.
I've tried things like just looping through all items and setting tag to nil, but saving the model context fails because somewhere in there it still tries to validate the old value.
Thanks!
我正在使用 Core Data 开发一个 SwiftUI 项目。我的数据模型中有一个名为 AppleUser 的实体,具有以下属性:id (UUID)、name (String)、email (String)、password (String) 和 createdAt (Date)。所有属性都是非可选的。
我使用 Xcode 的自动生成创建了相应的 Core Data 类文件(AppleUser+CoreDataClass.swift 和 AppleUser+CoreDataProperties.swift)。我还有一个 PersistenceController,它使用模型名称 JobLinkModel 初始化 NSPersistentContainer。
当我尝试使用以下方法保存新的 AppleUser 对象时:
让用户 = AppleUser(上下文:viewContext)
user.id = UUID()
user.name = “用户 1”
user.email = “...”
user.password = “密码 1”
user.createdAt = Date()【电子邮件格式正确,但已替换为“...”出于隐私原因】
尝试?viewContext.save()
我在控制台中收到以下错误:核心数据保存失败:Foundation._GenericObjCError.nilError, [:]
用户快照: [“id”: ..., “name”: “User1”, “email”: “...”, “password”: “...”, “createdAt”: ...]
所有字段都有有效值,核心数据模型似乎正确。我还尝试过:
• 检查 NSPersistentContainer(name:) 中的模型名称是否与 .xcdatamodeld 文件 (JobLinkModel) 匹配
• 确保正确设置 AppleUser 实体类、模块和 Codegen(类定义、当前产品模块)
• 删除重复或旧的 AppleUser 类文件
• 清理 Xcode 构建文件夹并从模拟器中删除应用程序
• 对上下文使用 @Environment(.managedObjectContext)
尽管如此,在保存新的 AppleUser 对象时,我仍然会收到 _GenericObjCError.nilError。
我想了解:
为什么即使所有字段都不是零且正确分配,核心数据也无法保存?
这可能是由于一些残留的旧类文件引起的,还是我缺少设置中的其他内容?
我应该采取哪些步骤来确保 Core Data 正确识别 AppleUser 实体并允许保存?
任何帮助或指导将不胜感激。
Hi all,
I have setup my app to use SwiftData with CloudKit sync. I have a production environment and development environment. I can reset the development environment for myself and all users in CloudKit console, but I can't reset the production one as it's tried to users' iCloud accounts, so I've added a button in-app for that feature. In the onboarding of my app, I pre-seed the DB with some default objects, which should be persisted between app install. The issue I'm running into is that I'm unable to force-pull these models from iCloud during the onboarding of a clean re-install, which leads to the models later appearing as duplicates once the user has been on the app for a few minutes and it has pulled from their iCloud account. If anyone has any suggestions on how to handle this issue, I would greatly appreciate it.
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.