Hi all,
I am using SwiftData and cloudkit and I am having an extremely persistent bug.
I am building an education section on a app that's populated with lessons via a local JSON file. I don't need this lesson data to sync to cloudkit as the lessons are static, just need them imported into swiftdata so I've tried to use the modelcontainer like this:
static func createSharedModelContainer() -> ModelContainer {
// --- Define Model Groups ---
let localOnlyModels: [any PersistentModel.Type] = [
Lesson.self, MiniLesson.self,
Quiz.self, Question.self
]
let cloudKitSyncModels: [any PersistentModel.Type] = [
User.self, DailyTip.self, UserSubscription.self,
UserEducationProgress.self // User progress syncs
]
However, what happens is that I still get Lesson and MiniLesson record types on cloudkit and for some reason as well, whenever I update the data models or delete and reinstall the app on simulator, the lessons duplicate (what seems to happen is that a set of lessons comes from the JSON file as it should), and then 1-2 seconds later, an older set of lessons gets synced from cloudkit.
I can delete the old set of lessons if I just delete the lessons and mini lessons record types, but if I update the data model again, this error reccurrs.
Sorry, I don't know if I managed to explain this well but essentially I just want to stop the lessons and minilessons from being uploaded to cloudkit as I think this will fix the problem. Am I doing something wrong with the code?
iCloud & Data
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My app uses iCloud to let users sync their files via their private iCloud Drive, which does not use CloudKit.
FileManager.default.url(forUbiquityContainerIdentifier: nil)?.appending(component: "Documents")
I plan to transfer my app to another developer account, but I'm afraid it will affect the access of the app to the existing files in that folder. Apple documentation doesn't mention this case.
Has anyone done this before and can confirm if the app will continue to work normally after transferring?
Thanks
I'm trying to use the new (in tvOS 26) video streaming service automatic login API from the VideoSubscriberAccount framework:
https://developer.apple.com/documentation/videosubscriberaccount/vsuseraccountmanager/autosignintoken-swift.property
It seems that this API requires an entitlement. This document suggests that the com.apple.smoot.subscriptionservice entitlement is required.
https://developer.apple.com/documentation/videosubscriberaccount/signing-people-in-to-media-apps-automatically
However, it seems more likely that com.apple.developer.video-subscriber-single-sign-on is the correct entitlement.
https://developer.apple.com/documentation/bundleresources/entitlements/com.apple.developer.video-subscriber-single-sign-on
Which is the correct entitlement and how do I obtain it?
I don't want to fully comply with the video partner program.
https://developer.apple.com/programs/video-partner/
I just want to use this one new automatic login feature.
We're in the process of migrating our app to the Swift 6 language mode. I have hit a road block that I cannot wrap my head around, and it concerns Core Data and how we work with NSManagedObject instances.
Greatly simplied, our Core Data stack looks like this:
class CoreDataStack {
private let persistentContainer: NSPersistentContainer
var viewContext: NSManagedObjectContext { persistentContainer.viewContext }
}
For accessing the database, we provide Controller classes such as e.g.
class PersonController {
private let coreDataStack: CoreDataStack
func fetchPerson(byName name: String) async throws -> Person? {
try await coreDataStack.viewContext.perform {
let fetchRequest = NSFetchRequest<Person>()
fetchRequest.predicate = NSPredicate(format: "name == %@", name)
return try fetchRequest.execute().first
}
}
}
Our view controllers use such controllers to fetch objects and populate their UI with it:
class MyViewController: UIViewController {
private let chatController: PersonController
private let ageLabel: UILabel
func populateAgeLabel(name: String) {
Task {
let person = try? await chatController.fetchPerson(byName: name)
ageLabel.text = "\(person?.age ?? 0)"
}
}
}
This works very well, and there are no concurrency problems since the managed objects are fetched from the view context and accessed only in the main thread.
When turning on Swift 6 language mode, however, the compiler complains about the line calling the controller method:
Non-sendable result type 'Person?' cannot be sent from nonisolated context in call to instance method 'fetchPerson(byName:)'
Ok, fair enough, NSManagedObject is not Sendable. No biggie, just add @MainActor to the controller method, so it can be called from view controllers which are also main actor. However, now the compiler shows the same error at the controller method calling viewContext.perform:
Non-sendable result type 'Person?' cannot be sent from nonisolated context in call to instance method 'perform(schedule:_:)'
And now I'm stumped. Does this mean NSManageObject instances cannot even be returned from calls to NSManagedObjectContext.perform? Ever? Even though in this case, @MainActor matches the context's actor isolation (since it's the view context)?
Of course, in this simple example the controller method could just return the age directly, and more complex scenarios could return Sendable data structures that are instantiated inside the perform closure. But is that really the only legal solution? That would mean a huge refactoring challenge for our app, since we use NSManageObject instances fetched from the view context everywhere. That's what the view context is for, right?
tl;dr: is it possible to return NSManagedObject instances fetched from the view context with Swift 6 strict concurrency enabled, and if so how?
We are currently implementing a custom iCloud sync for our macOS and iOS apps using CloudKit. Syncing works fine as long as the number of record sends is relatively small.
But when we test with a large number of changes ( 80,000+ CKRecords ) we start running into problems.
Our sending strategy is very conservative to avoid rate limits:
We send records sequentially in batches of 250 records
With about 2 seconds pause between operations
Records are small and contain no assets (assets are uploaded separately)
At some point we start receiving:
“Database commit size exceeds limit”
After that, CloudKit begins returning rate-limit errors with retryAfter-Information in the error.
We wait for the retry time and try again, but from this moment on, nothing progresses anymore. Every subsequent attempt fails.
We could not find anything in the official documentation regarding such a “commit size” limit or what triggers this failure state.
So my questions are:
Are there undocumented limits on the total number of records that can exist in an iCloud database (private or shared)?
Is there a maximum volume of record modifications a container can accept within a certain timeframe, even if operations are split into small batches with pauses?
Is it possible that sending large numbers of records in a row can temporarily or permanently “stall” a CloudKit container?
Any insights or experiences would be greatly appreciated.
Thank you!
My client is using iCloud Mail with his custom domain and he communicated with many govt organizations which seem to all be using Barracuda Email Protection for their spam prevention. I have properly configured his SPF, DKIM & DMARC DNS records however his emails were still being rejected. (Email header below)
I contacted Barracuda support with the email header and they replied saying that the emails were rejected becuase Apple Mail has missing PTR records.
I have sent dozens of emails for testing and looking at all their headers I can see (ms-asmtp-me-k8s.p00.prod.me.com [17.57.154.37]) which does not have a PTR record.
----FULL EMAIL HEADER WITH 3RD PARTY DOMAINS REMOVED-----
<recipient_email_address>: host
d329469a.ess.barracudanetworks.com[209.222.82.255] said: 550 permanent
failure for one or more recipients (recipient_email_address:blocked)
(in reply to end of DATA command)
Reporting-MTA: dns; p00-icloudmta-asmtp-us-west-3a-100-percent-10.p00-icloudmta-asmtp-vip.icloud-mail-production.svc.kube.us-west-3a.k8s.cloud.apple.com
X-Postfix-Queue-ID: 8979C18013F8
X-Postfix-Sender: rfc822; sender_email_address
Arrival-Date: Thu, 20 Mar 2025 12:30:05 +0000 (UTC)
Final-Recipient: rfc822; @******
Original-Recipient: rfc822;recipient_email_address
Action: failed
Status: 5.0.0
Remote-MTA: dns; d329469a.ess.barracudanetworks.com
Diagnostic-Code: smtp; 550 permanent failure for one or more recipients
(recipient_email_address:blocked)
Return-Path: <sender_email_address>
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sender_domain;
s=sig1; bh=CyUt/U7mIHwXB5OQctPjRH/OxLH7GsLR54JjGuRkj9Y=;
h=From:Message-Id:Content-Type:Mime-Version:Subject:Date:To:x-icloud-hme;
b=hwEbggsctiCRlMlEgovBTjB/0sPRCb2k+1wzHRZ2dZNrZdOqvFSNWU+Aki9Bl8nfv
eEOoXz5qWxO2b2rEBl08lmRQ3hCyroayIn4keBRrgkxL1uu4zMTaDUHyau2vVnzC3h
ZmwQtQxiu7QvTS/Sp8jjJ/niOPSzlfhphqMxnQAZi/jmJGcZPadT8K+7+PhRllVnI+
TElJarN1ORQu+CaPGhEs9/F7AIcjJNemnVg1cude7EUuO9va8ou49oFExWTLt7YSMl
s+88hxxGu3GugD3eBnitzVo7s7/O9qkIbDUjk3w04/p/VOJ+35Mvi+v/zB9brpYwC1
B4dZP+AhwJDYA==
Received: from smtpclient.apple (ms-asmtp-me-k8s.p00.prod.me.com [17.57.154.37])
by p00-icloudmta-asmtp-us-west-3a-100-percent-10.p00-icloudmta-asmtp-vip.icloud-mail-production.svc.kube.us-west-3a.k8s.cloud.apple.com (Postfix) with ESMTPSA id 8979C18013F8;
Thu, 20 Mar 2025 12:30:05 +0000 (UTC)
From: Marcel Brunel <sender_email_address>
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Subject: Re: [EXTERNAL] - Re: Brunel - 2024 taxes
Date: Thu, 20 Mar 2025 07:29:27 -0500
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Topic:
App & System Services
SubTopic:
iCloud & Data
I'm building a photo editing app with a token-based subscription system using RevenueCat and StoreKit. Users purchase subscriptions that grant tokens for AI generations. There are no user accounts, the app is fully anonymous.
Currently, I generate an anonymous account ID via RevenueCat SDK and store it in iCloud Keychain. This allows users on the same iCloud account to restore both their subscription and token balance across devices. However, users on a different iCloud account can restore their subscription via Apple, but their token balance is lost because there's no way to link the anonymous IDs.
The problem is that if a user switches iCloud accounts or gets a new device without the same iCloud, their purchased tokens are orphaned. The subscription restores fine through Apple, but the token balance tied to the old anonymous ID becomes inaccessible.
I have a few constraints: no user accounts, no email or phone sign-in, must work across devices owned by the same person, and must comply with App Store guidelines.
My questions are: Is iCloud Keychain the right tool for this, or is there a better approach? Would CloudKit with an anonymous record zone be more appropriate? Are there any recommended patterns for persisting consumable balances tied to anonymous users across device migrations?
Any guidance would be appreciated.
Topic:
App & System Services
SubTopic:
iCloud & Data
SwiftData crashes 100% when fetching history of a model that contains an optional codable property that's updated:
SwiftData/Schema.swift:389: Fatal error: Failed to materialize a keypath for someCodableID.someID from CrashModel. It is possible that this path traverses a type that does not work with append(), please file a bug report with a test.
Would really appreciate some help or even a workaround.
Code:
import Foundation
import SwiftData
import Testing
struct VaultsSwiftDataKnownIssuesTests {
@Test
func testCodableCrashInHistoryFetch() async throws {
let container = try ModelContainer(
for: CrashModel.self,
configurations: .init(
isStoredInMemoryOnly: true
)
)
let context = ModelContext(container)
try SimpleHistoryChecker.hasLocalHistoryChanges(context: context)
// 1: insert a new value and save
let model = CrashModel()
model.someCodableID = SomeCodableID(someID: "testid1")
context.insert(model)
try context.save()
// 2: check history it's fine.
try SimpleHistoryChecker.hasLocalHistoryChanges(context: context)
// 3: update the inserted value before then save
model.someCodableID = SomeCodableID(someID: "testid2")
try context.save()
// The next check will always crash on fetchHistory with this error:
/*
SwiftData/Schema.swift:389: Fatal error: Failed to materialize a keypath for someCodableID.someID from CrashModel. It is possible that this path traverses a type that does not work with append(), please file a bug report with a test.
*/
try SimpleHistoryChecker.hasLocalHistoryChanges(context: context)
}
}
@Model final class CrashModel {
// optional codable crashes.
var someCodableID: SomeCodableID?
// these actually work:
//var someCodableID: SomeCodableID
//var someCodableID: [SomeCodableID]
init() {}
}
public struct SomeCodableID: Codable {
public let someID: String
}
final class SimpleHistoryChecker {
static func hasLocalHistoryChanges(context: ModelContext) throws {
let descriptor = HistoryDescriptor<DefaultHistoryTransaction>()
let history = try context.fetchHistory(descriptor)
guard let last = history.last else {
return
}
print(last)
}
}
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.
I’m trying to build a CRUD app using SwiftData, @Query model and multidatepicker.
The data from a multidatepicker is stored or persists in SwiftData as Set = [].
My current dilemma is how to use SwiftData and @Query model Predicate to find all records on the current date.
I can’t find any SwiftData documentation or examples @Query using Set = [].
My CRUD app should retrieve all records for the current date. Unfortunately, I don’t know the correct @Query model syntax for Set = [].
Hi,
I’m completely stuck with a very strange CloudKit problem that started recently and has now killed all iCloud sync for a live production app.
What is happening
Production container: iCloud.gainzCloud (created ~11 months ago, has been working perfectly until now)
In Xcode 26.0 (17A321):
→ Signing & Capabilities → iCloud is enabled
→ Container correctly shows as iCloud.gainzCloud
→ App builds and runs on device/simulator with zero provisioning or container errors
CloudKit Dashboard (https://icloud.developer.apple.com/dashboard/): completely blank – “No containers found”
Result: CloudKit sync is dead for every user (development + production environments)
What I know for sure
Apple Developer Support confirmed the container iCloud.gainzCloud still exists and is correctly attached to my Team ID on their backend
Personal iCloud (Mail, Notes, Photos, etc.) syncs perfectly on the same Mac / same Apple ID under macOS Tahoe 26.1
I have NOT changed the password on either the Apple ID or the Developer Program account
New containers I create appear in Xcode but never show up in the Dashboard
Environment
macOS Tahoe 26.1 (latest)
Xcode Version 26.0 (17A321)
Has anyone on the new Tahoe/Xcode 26 releases seen the CloudKit Dashboard suddenly go completely empty while Xcode still “sees” the container just fine?
Any known trick to force the dashboard to re-index containers or clear whatever cache is broken?
Thanks a lot in advance – this is blocking all iCloud functionality for a released app with active users.
Topic:
App & System Services
SubTopic:
iCloud & Data
Testing Environment: iOS 18.4.1 / macOS 15.4.1
I am working on an iOS project that aims to utilize the user's iCloud Drive documents directory to save a specific directory-based file structure. Essentially, the app would create a root directory where the user chooses in iCloud Drive, then it would populate user generated files in various levels of nested directories.
I have been attempting to use NSMetadataQuery with various predicates and search scopes but haven't been able to get it to directly monitor changes to files or directories that are not in the root directory.
Instead, it only monitors files or directories in the root directory, and any changes in a subdirectory are considered an update to the direct children of the root directory.
Example
iCloud Drive Documents (Not app's ubiquity container)
User Created Root Directory (Being monitored)
File A
Directory A
File B
An insertion or deletion within Directory A would only return a notification with userInfo containing data for NSMetadataQueryUpdateChangedItemsKey relating to Directory A, and not the file or directory itself that was inserted or deleted. (Query results array also only contain the direct children.)
I have tried all combinations of these search scopes and predicates with no luck:
query.searchScopes = [
rootDirectoryURL,
NSMetadataQueryUbiquitousDocumentsScope,
NSMetadataQueryAccessibleUbiquitousExternalDocumentsScope,
]
NSPredicate(value: true)
NSPredicate(format: "%K LIKE '*.md'", NSMetadataItemFSNameKey)
NSPredicate(format: "%K BEGINSWITH %@", NSMetadataItemPathKey, url.path(percentEncoded: false))
I do see these warnings in the console upon starting my query:
[CRIT] UNREACHABLE: failed to get container URL for com.apple.CloudDocs
[ERROR] couldn't fetch remote operation IDs: NSError: Cocoa 257 "The file couldn’t be opened because you don’t have permission to view it."
"Error returned from daemon: Error Domain=com.apple.accounts Code=7 "(null)""
But I am not sure what to make of that, since it does act normally for finding updates in the root directory.
Hopefully this isn't a limitation of the API, as the only alternative I could think of would be to have multiple queries running for each nested directory that I needed updates for.
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
Files and Storage
iCloud Drive
Foundation
Hello, thank you Apple for supporting custom store with SwiftData and the Schema type is superb to work with. I have successfully set one up with SQL and have some feedback and issues regarding its APIs.
There’s a highlighted message in the documentation about not using internal restricted symbols directly, but they contradict with the given protocols and I am concerned about breaking any App Store rules. Are we allowed to use these? If not, they should be opened up as they’re useful.
BackingData is required to set up custom snapshots, initialization, and getting/setting values. And I want to use it with createBackingData() to directly initialize instances from snapshots when transferring them between server and client or concurrency.
RelationshipCollection for casting to-many relationships from backing data or checking if an array contains a PersistentModel.
SchemaProperty for type erasure in a collection.
Schema.Relationship has KeyPath properties, but it is missing for Schema.Attribute and Schema.CompositeAttribute. Which means you can’t purely depend on the schema to map data. I am unable to access the properties of a custom struct type in a predicate unless I use Mirror with schemaMetadata() or CustomStringConvertible on the KeyPath directly to extract it.
Trivial, but… the KeyPath property name is inconsistent (it’s all lowercase).
It would be nice to retrieve property names from custom struct types, since you are unable access CodingKeys that are auto synthesized by Codable for structs. But I recently realized they’re a part Schema.CompositeAttribute, however I don’t know how to match these without the KeyPath…
I currently map my entities using CodingKeys to their PredicateCodableKeyPathProviding.… but I wish for a simpler alternative!
It’s unclear how to provide the schema to the snapshot before new models are created.
I currently use a static property, but I want to make it flexible if more schemas and configurations are added later on.
I considered saving and loading the schema in a temporary location, but doubtful that the KeyPath values will be available as they are not Codable.
I suspect schemaMetadata() has the information I need to map the backing data without a schema for snapshots, but as mentioned previously, properties are inaccessible…
Allow access to entity metatypes, like value types from SchemaProperty. They’re useful for getting data out of snapshots and casting them to CodingKeys and PredicateCodableKeyPathProviding. They do not carry over when you provide them in the Schema.
I am unable to retrieve the primary key from PersistentIdentifier.
It seems like once you create one, you can’t get it out, like the DataStoreConfiguration in ModelContainer is not the one you used to set it up. I cannot cast it, it is an entirely different struct?
I have to use JSONSerialization to extract it, but I want to get it directly since it is not a column in my database. It is transformed when it goes to/from my tables.
It’s unknown how to support some schema options, such as Spotlight and CloudKit.
Allow for extending macro options, such as adding options to set as primary key, whether to auto increment, etc…
You can create a schema for super and sub entities, but it doesn’t appear you can actually set them up from the @Model macro or use inheritance on these models…
SwiftData history tracking seems incomplete for HistoryDelete, because that protocol requires HistoryTombstone, but this type cannot be instantiated, nor does it contain anything useful to infer from.
As an aside, I want to create my own custom ModelActor that is a global actor. However, I’m unable to replicate the executor that Apple provides where the executor has a ModelContext, because this type does not conform to Sendable. So how did Apple do this? The documentation doesn’t mention unchecked Sendable, but I figure if the protocol is available then we would be able to set up our own.
And please add concurrency features!
Anyway, I hope for more continued support in the future and I am looking forward to what’s new this WWDC! 😊
About 4 months ago, I shipped the first version of my app with 4 versioned schemas that, unintentionally, had the same versionIdentifier of 1.2.0 in 2 of them:
V1: 1.0.0
V2: 1.1.0
V3: 1.2.0
V4: 1.2.0
They are ordered correctly in the MigrationPlan, and they are all lightweight.
Migration works, SwiftData doesn't crash on init and I haven't encountered any issues related to this. The app syncs with iCloud.
Questions, preferable for anybody with knowledge of SwiftData internals:
What will break in SwiftData when there are 2 duplicate numbers?
Not that I would expect it to be safe, but does it happen to be safe to ship an update that changes V4's version to 1.3.0, what was originally intended?
Topic:
App & System Services
SubTopic:
iCloud & Data
Hey everyone, I have a question. When creating an app, how should I design a message table that involves personal privacy? The content is stored locally on the user's device, and then encrypted in the server database? How should I design it?
Topic:
App & System Services
SubTopic:
iCloud & Data
I am trying to save to cloud kit shared database. The shared database does not allow zones to be set up.
How do I save to sharedCloudDatabase without a zone?
private func addItem(recordType: String, name: String) {
let record = CKRecord(recordType: recordType)
record[Constances.field.name] = name as CKRecordValue
record[Constances.field.done] = false as CKRecordValue
record[Constances.field.priority] = 0 as CKRecordValue
CKContainer.default().sharedCloudDatabase.save(record) { [weak self] returnRecord, error in
if let error = error {
print("Error saving record: \(record[Constances.field.name] as? String ?? "No Name"): \n \(error)")
return
}
}
}
The following error message prints out:
Error saving record: Milk:
<CKError 0x15af87900: "Server Rejected Request" (15/2027); server message = "Default zone is not accessible in shared DB"; op = B085F7BA703D4A08; uuid = 87AEFB09-4386-4E43-81D7-971AAE8BA9E0; container ID = "iCloud.com.sfw-consulting.Family-List">
Hi,
I am implementing a premium feature in my app where CloudKit syncing is available only for "Pro" users.
The Workflow:
Free Users: I initialize the ModelContainer with cloudKitDatabase: .none so their data stays local.
Pro Upgrade: When a user purchases a subscription, I restart the container with cloudKitDatabase: .automatic to enable syncing.
The Problem:
If a user starts as "Free" (creates local data) and later upgrades to "Pro", the app crashes immediately upon launch with the following error:
Fatal error: Failed to create ModelContainer: SwiftDataError(_error: SwiftData.SwiftDataError._Error.loadIssueModelContainer, _explanation: nil)
It seems that SwiftData fails to load the existing data once the configuration changes to expect a CloudKit-backed store.
My Question:
Is there a supported way to "toggle" CloudKit on for an existing local dataset without causing this crash? I want the user's existing local data to start syncing once they pay, but currently, it just crashes.
My code:
import Foundation
import SwiftData
public enum DataModelEnum: String {
case task, calendar
public static let container: ModelContainer = {
let isSyncEnabled = UserDefaults.isProUser
let config = ModelConfiguration(
groupContainer: .identifier("group.com.yourcompany.myApp"),
cloudKitDatabase: isSyncEnabled ? .automatic : .none
)
do {
return try ModelContainer(for: TaskModel.self, CalendarModel.self, configurations: config)
} catch {
fatalError("Failed to create ModelContainer: \(error)")
}
}()
}
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
CloudKit
Cloud and Local Storage
SwiftData
I have used core data before via the model editor. This is the first time I'm using swift data and that too with CloudKit. Can you tell me if the following model classes are correct?
I have an expense which can have only one sub category which in turn belongs to a single category. Here are my classes...
// Expense.swift
// Pocket Expense Diary
//
// Created by Neerav Kothari on 16/05/25.
//
import Foundation
import SwiftData
@Model
class Expense {
@Attribute var expenseDate: Date? = nil
@Attribute var expenseAmount: Double? = nil
@Attribute var expenseCategory: Category? = nil
@Attribute var expenseSubCategory: SubCategory? = nil
var date: Date {
get {
return expenseDate ?? Date()
}
set {
expenseDate = newValue
}
}
var amount: Double{
get {
return expenseAmount ?? 0.0
}
set {
expenseAmount = newValue
}
}
var category: Category{
get {
return expenseCategory ?? Category.init(name: "", icon: "")
}
set {
expenseCategory = newValue
}
}
var subCategory: SubCategory{
get {
return expenseSubCategory ?? SubCategory.init(name: "", icon: "")
}
set {
expenseSubCategory = newValue
}
}
init(date: Date, amount: Double, category: Category, subCategory: SubCategory) {
self.date = date
self.amount = amount
self.category = category
self.subCategory = subCategory
}
}
//
// Category.swift
// Pocket Expense Diary
//
// Created by Neerav Kothari on 16/05/25.
//
import Foundation
import SwiftData
@Model
class Category {
@Attribute var categoryName: String? = nil
@Attribute var categoryIcon: String? = nil
var name: String {
get {
return categoryName ?? ""
}
set {
categoryName = newValue
}
}
var icon: String {
get {
return categoryIcon ?? ""
}
set {
categoryIcon = newValue
}
}
@Relationship(inverse: \Expense.expenseCategory) var expenses: [Expense]? = []
init(name: String, icon: String) {
self.name = name
self.icon = icon
}
}
// SubCategory.swift
// Pocket Expense Diary
//
// Created by Neerav Kothari on 16/05/25.
//
import Foundation
import SwiftData
@Model
class SubCategory {
@Attribute var subCategoryName: String? = nil
@Attribute var subCategoryIcon: String? = nil
var name: String {
get {
return subCategoryName ?? ""
}
set {
subCategoryName = newValue
}
}
var icon: String {
get {
return subCategoryIcon ?? ""
}
set {
subCategoryIcon = newValue
}
}
@Relationship(inverse: \Expense.expenseSubCategory) var expenses: [Expense]? = []
init(name: String, icon: String) {
self.name = name
self.icon = icon
}
}
The reason why I have wrappers is the let the existing code (before CloudKit was integrated), work.
In future versions I plan to query expenses even via category or sub category. I particularly doubt for the relationship i have set. should there be one from category to subcategory as well?
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
}
}
I have an iOS app using SwiftData with VersionedSchema. The schema is synchronized with an CloudKit container.
I previously introduced some model properties that I have now removed, as they are no longer needed. This results in the current schema version being identical to one of the previous ones (except for its version number).
This results in the following exception:
'NSInvalidArgumentException', reason: 'Duplicate version checksums across stages detected.'
So it looks like we cannot have a newer schema version with an identical content to an older schema version.
The intuitive way would be to re-add the old (identical) schema version to the end of the "schemas" list property in the SchemaMigrationPlan, in order to signal that it is the newest one, and to add a migration stage back to it, thus:
public enum MySchemaMigrationPlan: SchemaMigrationPlan {
public static var schemas: [any VersionedSchema.Type] {
[
SchemaV100.self,
SchemaV101.self,
SchemaV100.self
]
}
public static var stages: [MigrationStage] {
[
migrateV100toV101,
migrateV101toV100
]
}
However, I am not sure if this is the right way to go, as previously, as I wanted to write unit tests for schema migration and rollback, I tried defining an inverse for each migration stage, so that I could trigger a migration and a rollback from a unit test, which resulted in an exception saying that it is not supported to downgrade a VersionedSchema.
I must admit that I solved the original problem by introducing a dummy model property that I will later remove. What would have been the correct approach?