Hi,
I have designed an app which needs to reschedule notifications according to the user's calendar at midnight. The function has been implemented successfully via backgroundtask. But since the app has enabled iCloud sync, some users will edit their calendar on their iPad and expect that the notifications will be sent promptly to them on iPhone without launching the app on their iPhone. But the problem is that if they haven't launched the app on their iPhone, iCloud sync won't happen. The notifications on their iPhone haven't been updated and will be sent wrongly. How can I design some codes to let iCloud sync across the devices without launching the app at midnight and then reschedule notifications?
iCloud & Data
RSS for tagLearn how to integrate your app with iCloud and data frameworks for effective data storage
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When I try to use an entity created in a CoreData, it gives me: 'PlayerData' is ambiguous for type lookup in this context
I am having problems when I first loads the app. The time it takes for the Items to be sync from my CloudKit to my local CoreData is too long.
Code
I have the model below defined by my CoreData.
public extension Item {
@nonobjc class func fetchRequest() -> NSFetchRequest<Item> {
NSFetchRequest<Item>(entityName: "Item")
}
@NSManaged var createdAt: Date?
@NSManaged var id: UUID?
@NSManaged var image: Data?
@NSManaged var usdz: Data?
@NSManaged var characteristics: NSSet?
@NSManaged var parent: SomeParent?
}
image and usdz columns are both marked as BinaryData and Attribute Allows External Storage is also selected.
I made a Few tests loading the data when the app is downloaded for the first time. I am loading on my view using the below code:
@FetchRequest(
sortDescriptors: [NSSortDescriptor(keyPath: \Item.createdAt, ascending: true)]
)
private var items: FetchedResults<Item>
var body: some View {
VStack {
ScrollView(.vertical, showsIndicators: false) {
LazyVGrid(columns: columns, spacing: 40) {
ForEach(items, id: \.self) { item in
Text(item.id)
}
}
}
}
}
Test 1 - Just loads everything
When I have on my cloudKit images and usdz a total of 100mb data, it takes around 140 seconds to show some data on my view (Not all items were sync, that takes much longer time)
Test 2 - Trying getting only 10 items at the time ()
This takes the same amount of times the long one . I have added the following in my class, and removed the @FetchRequest:
@State private var items: [Item] = [] // CK
@State private var isLoading = false
@MainActor
func loadMoreData() {
guard !isLoading else { return }
isLoading = true
let fetchRequest = NSFetchRequest<Item>(entityName: "Item")
fetchRequest.predicate = NSPredicate(format: "title != nil AND title != ''")
fetchRequest.fetchLimit = 10
fetchRequest.fetchOffset = items.count
fetchRequest.predicate = getPredicate()
fetchRequest.sortDescriptors = [NSSortDescriptor(keyPath: \Item.createdAt, ascending: true)]
do {
let newItems = try viewContext.fetch(fetchRequest)
DispatchQueue.main.async {
items.append(contentsOf: newItems)
isLoading = false
}
} catch {}
}
Test 2 - Remove all images and usdz from CloudKit set all as Null
Setting all items BinaryData to null, it takes around 8 seconds to Show the list.
So as we can see here, all the solutions that I found are bad. I just wanna go to my CloudKit and fetch the data with my CoreData. And if possible to NOT fetch all the data because that would be not possible (imagine the future with 10 or 20GB or data) What is the solution for this loading problem? What do I need to do/fix in order to load lets say 10 items first, then later on the other items and let the user have a seamlessly experience?
Questions
What are the solutions I have when the user first loads the app?
How to force CoreData to query directly cloudKit?
Does CoreData + CloudKit + NSPersistentCloudKitContainer will download the whole CloudKit database in my local, is that good????
Storing images as BinaryData with Allow external Storage does not seems to be working well, because it is downloading the image even without the need for the image right now, how should I store the Binary data or Images in this case?
I have a SwiftData application that is using CloudKit. If user is on new device. How can I check and fetch data, instead of just waiting for it happen on its own randomly?
For example, I have onboarding which I do not want user to go through again if they already have an active installation.
Seems like SwiftData is severely limited in pretty much every way, specially any useful CloudKit debugging or control functionality.
Hi everyone,
I’m currently developing a SwiftUI app that uses SwiftData with CloudKit sharing enabled. The app works fine on my own Apple ID, and local syncing with iCloud is functioning correctly — but sharing with other Apple IDs consistently fails.
Setup:
SwiftUI + SwiftData using a ModelContainer with .shared configuration
Sharing UI is handled via UICloudSharingController
iCloud container: iCloud.com.de.SkerskiDev.FoodGuard
Proper entitlements enabled (com.apple.developer.icloud-services, CloudKit, com.apple.developer.coredata.cloudkit.containers, etc.)
Automatic provisioning profiles created by Xcode
Error:<CKError 0x1143a2be0: "Bad Container" (5/1014);
"Couldn't get container configuration from the server for container iCloud.com.de.SkerskiDev.FoodGuard">
What I’ve tried:
Verified the iCloud container is correctly created and enabled in the Apple Developer portal
Checked bundle identifier and container settings
Rebuilt and reinstalled the app
Ensured correct iCloud entitlements and signing capabilities
Questions:
Why does CloudKit reject the container for sharing while local syncing works fine?
Are there known issues with SwiftData .shared containers and multi-user sharing?
Are additional steps required (App Store Connect, privacy settings) to allow sharing with other Apple IDs?
Any advice, experience, or example projects would be greatly appreciated. 🙏
Thanks!
Sebastian
I implemented the cloudkit function, where users can connect with each other. The problem is, that if User A is doing a friend request and User B is accepting the request. The friend entry is correct visible for User B but not for User A. I can see in cloud kit that after the accepted request, the friend connection is set up correctly, also with the correct userID, but it not showing up for User A (the one that send the request)
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
CloudKit
CloudKit Dashboard
CloudKit Console
if it set com.apple.CoreData.ConcurrencyDebug 1 as launch arg the app always crashes and i cant proceed into the app. is there a way to only raise a warning for these issues so that i can go into the app and check every place in one session for coredata errors?
My project is using swiftData and I want to implement iCloud sync in it. Now, my data base doesnt have any optional attributes or relationships and CloudKit wants them to be optional.
So, rather than editing all code with unwrapping code for the optionals, how can I provide a bridge that does so in the last stage of actually saving to the store? Sort of, capture it in a proxy object before writing and after reading from the store.
Is there a neat way that can save a lot of debugging? I have code snippets from chat gpt and they are hard to debug. This is my first project in swiftUI.
Thanks.
Neerav
I am using cloudkit to save users high scores in a public database. The preference over using Game Center is because of simplicity and works really well for what I want to achieve. I simply want to let users know their global position. Because of data privacy laws the app asks the user for their permission to submit their score each time they get a new high score.
However, I have noticed that CKRecords under 'created' and 'modified' in addition to UTC time and date also contain creatorUserRecordID. Could this be a privacy issue? Can you extract any personal information from this? Can this be used to track back to the user? Is it linked to CKUserIdentity which I understand does contain personal information, although as I understand you need users consent to get this information. Under creatorUserRecordID it says... "Every user of the app has a unique user record that is empty by default. Apps can add data to the user record on behalf of the user, but don’t store sensitive data in it"
Currently I simply ask the user if they are happy to submit their score. But do I need to point out that it also stores a creatorUserRecordID? Obviously I don't want to do this if it is not needed as the user will 1) Probably not understand what a creatorUserRecordID is and 2) It makes the question complicated and will likely make most people refuse to submit their score.
If it is a privacy issue, is there anyway to stop a CKRecord creating this ID and simply save a score? All I need is a list of scores so the app can determine their current position.
If creatorUserRecordID does not contain any personal details and cannot be tracked back to the user please let me know, so I can be reassured that my current set up is fine and I am not causing any privacy issues!
This post did seem to indicate you may possibly be able to fetch personal details??
https://stackoverflow.com/questions/55782166/how-do-i-fetch-any-info-about-user-that-modified-ckrecord
When I tried to use a working project with iOS 18 installed on my device, it wouldn't work anymore and crash right away. Before with iOS 17 it was working fine.
I can't access child variables that are saved in an Array in a parent object in SwiftData. The error is always somewhere in these hidden lines:
{
@storageRestrictions(accesses: _$backingData, initializes: _title)
init(initialValue) {
_$backingData.setValue(forKey: \.title, to: initialValue)
_title = _SwiftDataNoType()
}
get {
_$observationRegistrar.access(self, keyPath: \.title)
return self.getValue(forKey: \.title)
}
set {
_$observationRegistrar.withMutation(of: self, keyPath: \.title) {
self.setValue(forKey: \.title, to: newValue)
}
}
}
The child classes are also inserted and saved into the modelContext when created and set to the parent instance, but I also can't fetch them via modelContext.fetch() - Error here is:
Thread 1: EXC_BREAKPOINT (code=1, subcode=0x243a62a4c)
Maybe there is a problem with the relationship between two saved instances.
The parent instances are saved correctly and it was working in iOS 17.
The problem is similar to these two cases:
https://forums.developer.apple.com/forums/thread/762679
https://forums.developer.apple.com/forums/thread/738983
I changed the logic after I reviewed these threads, as I am now linking the parent and child instances, that got rid of one warning in the console.
button.canvas = canvas
modelContext.insert(button)
canvas.buttons = [button]
But in the end those threads were not enough for me to find a fix for my problem.
A small project can be found here:
https://github.com/DonMalte/SwiftDataTest
Topic:
App & System Services
SubTopic:
iCloud & Data
While experimenting with CloudKit dashboard, I accidentally turned off a iCloud container.
Now in the Certificates, Identifiers & Profiles section of developer portal, this iCloud container identifier is listed under "hidden" not "active"
I can edit its name but there is not way to unhide or active it again.
What am I missing?
Topic:
App & System Services
SubTopic:
iCloud & Data
Is it possible to track history using the new HistoryDescriptor feature in SwiftData? Or can I only get the current most recent data? Or is it possible to output the changed data itself, along with timestamps?
I am hoping that it is possible to track by a standard feature like NSPersistentHistoryTransaction in CoreData.
Do we still have to use a method in SwiftData that creates more tracking data itself?
Hello !
I am using this iCloud key value pair mechanism to save small app configuration between iOS and tvOS.
I would say it is working. But when I go back and forth between debug and release (TestFlight) modes, it is like both apps are not connected anymore.
I spend a lot of time restarting all devices, rebuilding, activating / deactivating iCloud capabilities in the Xcode project.
It is like the app is mixing debug and release data.
Is there an easy way to check what is happening exactly ? I know there's nothing on CloudKit console, so ....
Thank you
Frederic
Hi everyone!
I have an app on the App Store that uses Core Data as its data store. (It's called Count on Me: Tally Counter. Feel free to check it out.) One of the app's core feature is an interactive widget with a simple button. When the button is tapped, it's supposed to update the entity in the store.
My requirement is that the changes are then reflected with minimal latency in the main app and – ideally – also on other devices of the same iCloud user. And vice-versa: When an entity is updated in the app (or on another device where the same iCloud user is logged in), the widget that shows this entity should also refresh to reflect the changes.
I have read multiple articles, downloaded sample projects, searched Stackoverflow and the Apple developer forums, and tried to squeeze a solution out of AI, but couldn't figure out how to make this work reliably.
So I tried to reduce the core problem to a minimal example project. It has two issues that I cannot resolve:
When I update an entity in the app, the widget is immediately updated as intended (due to a call to WidgetCenter's reloadAllTimelines method). However, when I update the same entity from the interactive widget using the same app intent, the changes are not reflected in the main app.
For the widget and the app to use the same local data store, I need to enable App Groups in both targets and set a custom location for the store within the shared app group. So I specify a custom URL for the NSPersistentStoreDescription when setting up the Core Data stack. The moment I do this, iCloud sync breaks.
Issue no. 1 is far more important to me as I haven't officially enabled iCloud sync yet in my real app that's already on the App Store. But it would be wonderful to resolve issue no. 2 as well. Surely, there must be a way to synchronize changes to the source of truth triggered by interactive widget with other devices of the same iCloud user. Otherwise, the feature to talk to the main app and the feature to synchronize with iCloud would be mutually exclusive.
Some other developers I talked to have suggested that the widget should only communicate proposed changes to the main app and once the main app is opened, it processes these changes and writes them to the NSPersistentCloudKitContainer which then synchronizes across devices. This is not an option for me as it would result in a stale state and potential data conflicts with different devices. For example, when a user has the same widget on their iPhone and their iPad, taps a button on the iPhone widget, that change would not be reflected on the iPad widget until the user decides to open the app on the iPhone. At the same time, the user could tap the button multiple times on their iPad widget, resulting in a conflicting state on both devices. Thus, this approach is not a viable solution.
An answer to this question will be greatly appreciated. The whole code including the setup of the Core Data stack is included in the repository reference above. Thank you!
I get the following fatal error when the user clicks Save in AddProductionView.
Fatal error: Duplicate keys of type 'AnyHashable' 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.
As far as I’m aware, SwiftData automatically makes its models conform to Hashable, so this shouldn’t be a problem.
I think it has something to do with the picker, but for the life of me I can’t see what.
This error occurs about 75% of the time when Save is clicked.
I'm using Xcode 16.2 and iPhone SE 2nd Gen. Any help would be greatly appreciated…
Here is my code:
import SwiftUI
import SwiftData
@main
struct MyApp: App {
var body: some Scene {
WindowGroup {
ContentView()
.modelContainer(for: Character.self, isAutosaveEnabled: false)
}
}
}
@Model
final class Character {
var name: String
var production: Production
var myCharacter: Bool
init(name: String, production: Production, myCharacter: Bool = false) {
self.name = name
self.production = production
self.myCharacter = myCharacter
}
}
@Model
final class Production {
var name: String
init(name: String) {
self.name = name
}
}
struct ContentView: View {
@State private var showingSheet = false
var body: some View {
Button("Add", systemImage: "plus") {
showingSheet.toggle()
}
.sheet(isPresented: $showingSheet) {
AddProductionView()
}
}
}
struct AddProductionView: View {
@Environment(\.dismiss) private var dismiss
@Environment(\.modelContext) var modelContext
@State var production = Production(name: "")
@Query var characters: [Character]
@State private var characterName: String = ""
@State private var selectedCharacter: Character?
var filteredCharacters: [Character] {
characters.filter { $0.production == production }
}
var body: some View {
NavigationStack {
Form {
Section("Details") {
TextField("Title", text: $production.name)
}
Section("Characters") {
List(filteredCharacters) { character in
Text(character.name)
}
HStack {
TextField("Character", text: $characterName)
Button("Add") {
let newCharacter = Character(name: characterName, production: production)
modelContext.insert(newCharacter)
characterName = ""
}
.disabled(characterName.isEmpty)
}
if !filteredCharacters.isEmpty {
Picker("Select your role", selection: $selectedCharacter) {
Text("Select")
.tag(nil as Character?)
ForEach(filteredCharacters) { character in
Text(character.name)
.tag(character as Character?)
}
}
.pickerStyle(.menu)
}
}
}
.toolbar {
Button("Save") { //Fatal error: Duplicate keys of type 'AnyHashable' 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.
if let selectedCharacter = selectedCharacter {
selectedCharacter.myCharacter = true
}
modelContext.insert(production)
do {
try modelContext.save()
} catch {
print("Failed to save context: \(error)")
}
dismiss()
}
.disabled(production.name.isEmpty || selectedCharacter == nil)
}
}
}
}
It takes a few seconds, sometimes a few minutes for records to be downloaded back from CloudKit when the user reinstalls the app, which leads users to thinking their data was lost. I would like to know if there’s any way to provide a visual feedback about the current CloudKit sync status so I can let users know their data is being in fact downloaded back to their devices.
Hey guys, I'm developing a Swift app, using iCloud to store some data in Containers, and the new Containers I created are iCloud.com.xxx.dev . Therefore, there is a storage called dev in Settings -> icloud -> Manage Account Storage. Currently, the app is still under development and has not been released to the Appstore.
My question: Settings -> icloud -> Manage Account Storage does not display my app name and icon, but only the suffix of the Containers id. Will this change after it is released to the Appstore? Are there any other control methods? Thank you
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.
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
CloudKit
Cloud and Local Storage
iCloud Drive
Is there a way to move user data from UserDefaults to SwiftData when the app is in production so that people don’t lose their data. Currently my audio journals in my journal app has everything in the UserDefaults. Now this is bad for obvious reasons but I was thinking if there was a way. It’s only been 1 week since published and I have already had17 people download it.
Hi Developer Community,
I'm experiencing a critical issue with CloudKit schema deployment that's blocking my app release. I've been trying to resolve this for several days and would appreciate any assistance from the community or Apple engineers.
Issue Description
I'm unable to deploy my CloudKit schema from development to production environment. When attempting to deploy through the CloudKit Dashboard, I either get an "Internal Error" message or the deployment button is disabled.
Environment Details
App: Reef Trak (Reef aquarium tracking app)
CloudKit Container: ************
Development Environment: Schema fully defined and working correctly
Production Environment: No schema deployed (confirmed in dashboard)
What I've Tried
Using the "Deploy Schema to Production" button in CloudKit Dashboard (results in "Internal Error")
Exporting schema from development and importing to production (fails)
Using CloudKit CLI tools with API token (results in "invalid-scope" errors)
Waiting 24-48 hours between attempts in case of propagation delays
Current Status
App works perfectly in development environment (when run from Xcode)
In TestFlight/sideloaded builds (production environment), the app attempts to fetch records but fails with "Did not find record type: Tank" errors
Log snippet showing the issue:
[2025-03-21] [CloudKit] Schema creation failed: Error saving record <CKRecordID: 0x******; recordName=SchemaSetup_Tank_-**---****, zoneID=_defaultZone:defaultOwner> to server: Cannot create new type Tank in production schema [2025-03-21] [CloudKit] Failed to create schema for Tank after 3 attempts [2025-03-21] [CloudKit] Error creating schema for Tank: Error saving record <CKRecordID: 0x****; recordName=SchemaSetup_Tank_---**-**********, zoneID=_defaultZone:defaultOwner> to server: Cannot create new type Tank in production schema
App Architecture & Critical Impact
My app "Reef Trak" is built around a core data model where the "Tank" entity serves as the foundational element of the entire application architecture. The Tank entity is not just another data type - it's the primary container that establishes the hierarchical relationship for all other entities:
All parameter measurements (pH, temperature, salinity, etc.) are associated with specific tanks
All maintenance tasks and schedules are tank-specific
All livestock (fish, corals, invertebrates) exist within the context of a tank
All user achievements and progress tracking depend on tank-related activities
Without the Tank schema being properly deployed to production, users experience what appears to be a completely empty application, despite successful authentication and CloudKit connection. The app shows "Successfully retrieved iCloud data" but displays no content because:
The Tank record type doesn't exist in production
Without Tanks, all child entities (even if their schemas existed) have no parent to associate with
This creates a cascading failure where no data can be displayed or saved
This issue effectively renders the entire application non-functional in production, despite working flawlessly in development. Users are left with an empty shell of an app that cannot fulfill its core purpose of reef tank management and monitoring.
The inability to deploy the Tank schema to production is therefore not just a minor inconvenience but a complete blocker for the app's release and functionality.
Questions
Is there an alternative method to deploy schema to production that I'm missing?
Could there be an issue with my account permissions or container configuration?
Are there known issues with the CloudKit Dashboard deployment functionality?
What's the recommended approach when the dashboard deployment fails?
I've also submitted a Technical Support Incident, but I'm hoping to get this resolved quickly as it's blocking my App Store release.
Thank you for any assistance!
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
CloudKit
CloudKit Dashboard
CloudKit Console
cktool