NSPersistentCloudKitContainer

In testing today, syncing in the background with NSPersistentCloudKitContainer seems to be working more reliably with the iOS 16 SDK. The first time you change something on another device it still seems to schedule a task to perform that work with utility priority (via -[NSCloudKitMirroringDelegate checkAndScheduleImportIfNecessary:andStartAfterDate:] which logs Scheduling automated import with activity CKSchedulerActivity priority 2 Utility), so it doesn't execute right away. If you change it again then I'm seeing it does immediately import the two accumulated changes (NSCloudKitMirroringDelegate Beginning automated import - ImportActivity - in response to activity, then -[PFCloudKitImportRecordsWorkItem applyAccumulatedChangesToStore:inManagedObjectContext:withStoreMonitor:madeChanges:error:] followed by NSCloudKitMirroringImportRequest Importing updated records) which triggers NSManagedObjectContextObjectsDidChange, NSPersistentStoreRemoteChange, and NSPersistentCloudKitContainer.eventChangedNotif

If anyone is curious the first part of a post (https://www.andrewcbancroft.com/blog/ios-development/data-persistence/getting-started-with-nspersistentcloudkitcontainer/) got me started and then the Apple Documentation - specifically Setting Up Core Data with CloudKit to me the rest of the way. I mostly jumped around the documentation from there (got data loading when I started the app) and then Hacking with Swift got me the rest of the way.

Are you using manually syncing your CloudKit with CoreData or are you using NSPersistentCloudKitContainer? If you using NSPersistentCloudKitContainer does the syncing for you, don't have to set any custom zone, it would set a custom zone automatically. If you are doing it manually, then you would need to set a custom zone when you are saving a record and when you are retrieving it not while loading the container's persistent stores (which is what you are doing).

Problem 1: NSPersistentCloudKitContainer doesn't seem to work on simulator Solution: Use device, haven't found a way to make it work on the simulator. Problem2 When using CloudKit APIs (not NSPersistentCloudKitContainer) on the simulator I was getting CKError.notAuthenticated even though I had signed into iCloud on the simulator Root cause This happens when 2FA was enabled on the iCloud account but the 2FA code was asked on the simulator Solution Go to https://appleid.apple.com/, select devices on the sidebar Remove simulator (I found 2 simulators, removed both) Reset Xcode simulator Log into iCloud on the simulator Run the app Hopefully that should work.

By mistake i set the store descriptions inside if (error ! = nil) I changed that... yet no go... - (NSPersistentCloudKitContainer *)persistentContainer { // The persistent container for the application. This implementation creates and returns a container, having loaded the store for the application to it. @synchronized (self) { if (_persistentContainer == nil) { _persistentContainer = [[NSPersistentCloudKitContainer alloc] initWithName:@Expenses]; [_persistentContainer loadPersistentStoresWithCompletionHandler:^(NSPersistentStoreDescription *storeDescription, NSError *error) { if (error != nil) { #ifdef DEBUG NSLog(@Unresolved error %@, %@, error, error.userInfo); #endif abort(); } else #ifdef DEBUG NSLog(@Store successfully initialized); #endif [storeDescription setOption:[NSNumber numberWithBool:YES] forKey:@PersistentHistoryTracking]; [storeDescription setOption:[NSNumber numberWithBool:YES] forKey:@NSPersistentStoreRemoteChangeNotificationOptionKey]; }]; } } return _persistentContainer;

I think in built constants have to be used for keys so i changed the code to following... - (NSPersistentCloudKitContainer *)persistentContainer { // The persistent container for the application. This implementation creates and returns a container, having loaded the store for the application to it. @synchronized (self) { if (_persistentContainer == nil) { _persistentContainer = [[NSPersistentCloudKitContainer alloc] initWithName:@Expenses]; [_persistentContainer loadPersistentStoresWithCompletionHandler:^(NSPersistentStoreDescription *storeDescription, NSError *error) { if (error != nil) { #ifdef DEBUG NSLog(@Unresolved error %@, %@, error, error.userInfo); #endif abort(); } else { #ifdef DEBUG NSLog(@Store successfully initialized); #endif [storeDescription setOption:[NSNumber numberWithBool:YES] forKey:NSPersistentHistoryTrackingKey]; [storeDescription setOption:[NSNumber numberWithBool:YES] forKey:NSPersistentStoreRemoteChangeNotificationPostOptionKey]; } }]; } return _persistentContainer