Issue with SwiftData: “no such table: ZAPPSETTINGS” and SQLite I/O error on app launch
Hello,
I’m encountering persistent errors with SwiftData in my SwiftUI app related to Core Data’s underlying SQLite database. Despite defining my models correctly, the app fails to initialize the persistent store, throwing the following error on startup:
CoreData error: SQLCore dispatchRequest: no such table: ZAPPSETTINGS. I/O error opening database at /.../default.store. SQLite error code:1, NSSQLiteErrorDomain=1.
File “default.store” couldn’t be opened.
Context
The error only appears concerning my AppSettings model.
I have another model, LocationPoint, which appears correctly defined and used.
I have tried deleting the app, resetting the device, and cleaning builds but the error persists.
The error message suggests the database file is present but the table for ZAPPSETTINGS (the Core Data table for AppSettings) does not exist.
Code Samples
Main App Entry
import SwiftData
import SwiftUI
@main
struct Krow3_0App: App {
@State private var userLocationManager = UserLocationManager()
@State private var geocodingViewModel = GeocodingViewModel()
@State private var locationSearchViewModel = LocationSearchViewModel()
@State private var router = Router()
var body: some Scene {
WindowGroup {
LaunchView()
.environment(userLocationManager)
.environment(geocodingViewModel)
.environment(locationSearchViewModel)
.environment(router)
.modelContainer(for: [LocationPoint.self, AppSettings.self])
}
}
}
AppSettings Model
import Foundation
import SwiftData
@Model
class AppSettings {
var isMetric: Bool
init(isMetric: Bool = false) {
self.isMetric = isMetric
}
}
What I’ve Tried
Fully uninstalling and reinstalling the app on device and simulator.
Resetting the simulator/device.
Cleaning the Xcode build folder.
Verifying the schema logs which correctly list both LocationPoint and AppSettings.
Changing model names to avoid potential conflicts.
Adding .modelContainer configuration with autosave enabled.
Questions
Is there a known bug or limitation with SwiftData concerning certain model setups or naming?
Could this be related to how the data container initializes or migrates schemas?
Are there recommended debugging or migration steps to resolve “no such table” SQLite errors with SwiftData?
How can I safely reset or migrate the persistent store without corrupting the database?
Any insights or suggestions would be greatly appreciated!
Thank you!
SwiftData
RSS for tagSwiftData is an all-new framework for managing data within your apps. Models are described using regular Swift code, without the need for custom editors.
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Hello,
I am building a pretty large database (~40MB) to be used in my SwiftData iOS app as read-only.
While inserting and updating the data, I noticed a substantial increase in size (+ ~10MB).
A little digging pointed to ACHANGE and ATRANSACTION tables that apparently are dealing with Persistent History Tracking.
While I do appreciate the benefits of that, I prefer to save space.
Could you please point me in the right direction?
Hi !
Would anyone know (if possible) how to create backup files to export and then import from the data recorded by SwiftData?
For those who wish, here is a more detailed explanation of my case:
I am developing a small management software with customers and events represented by distinct classes. I would like to have an "Export" button to create a file with all the instances of these 2 classes and another "Import" button to replace all the old data with the new ones from a previously exported file.
I looked for several solutions but I'm a little lost...
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)
}
}
After the significant issues with the ModelActor in iOS 18, it seemed like the ModelActor became more stable with iOS 18.1 and macOS 15.1.
However, I’m still encountering problems and crashes. I wanted to ask if these issues are related to my persistence layer architecture or if they’re still inherent to the ModelActor itself.
I’ve generally followed the blog posts:
https://fatbobman.com/en/posts/practical-swiftdata-building-swiftui-applications-with-modern-approaches/
and
https://brightdigit.com/tutorials/swiftdata-modelactor/
and aim to achieve the following:
I have a single DataProvider that holds the ModelContainer and uses it to configure and initialize a single DataHandler. These are created once at app launch and injected into the SwiftUI view hierarchy as EnvironmentObjects. Since I need to access the SwiftData models not only in SwiftUI but also indirectly in ViewModels or UIKit views, all read operations on the models should go through the DataProvider (and its MainContext), while all other CRUD operations are handled centrally via the single DataHandler (executed within a single ModelActor).
Additionally, I want to monitor the entire container using another ModelActor, initialized in the DataProvider, which tracks changes to objects using TransactionHistory.
I’ve managed to implement this to some extent, but I’m facing two main issues:
1. ModelActor and Main Actor Requirement
The ModelActor only updates SwiftUI views when initialized via the maincontext of the ModelContainer and therefore runs on the Main Actor. It would be ideal for this to work in the background, but the issue with the ModelActor that existed previously doesn’t seem to have been resolved in iOS 18.1/macOS 15.1—am I wrong about this?
2. Frequent Crashes (more severe)
Crashes occur, especially when multiple windows on macOS or on iPad access the same DataHandler to update models. This often leads to crashes during read operations on models by a SwiftUI view (but not only), with logs like:
error: the replacement path doesn't exist: "/var/folders/gs/8rwdjczj225d1pj046w3d97c0000gn/T/swift-generated-sources/@__swiftmacro_12SwiftDataTSI3TagC4uuID18_PersistedPropertyfMa_.swift"
Can't show file for stack frame : <DBGLLDBStackFrame: 0x34d28e170> - stackNumber:1 - name:Tag.uuID.getter. The file path does not exist on the file system: /var/folders/gs/8rwdjczj225d1pj046w3d97c0000gn/T/swift-generated-sources/@__swiftmacro_12SwiftDataTSI3TagC4uuID18_PersistedPropertyfMa_.swift
This error usually happens when there are multiple concurrent accesses to the DataHandler/ModelActor. However, crashes also occur sporadically during frequent accesses from a single view with an error like "the replacement path doesn't exist."
It also seems like having multiple ModelActors, as in this case (one for observation and one for data changes), causes interference and instability. The app appears to crash less frequently when the observer is not initialized, but I can’t verify this—it might just be a coincidence.
My Question:
Am I fundamentally doing something wrong with the ModelActors or the architecture of my persistence layer?
I have been working on an app for the past few months, and one issue that I have encountered a few times is an error where quick subsequent deletions cause issues with detached tasks that are triggered from some user actions.
Inside a Task.detached, I am building an isolated model context, querying for LineItems, then iterating over those items. The crash happens when accessing a Transaction property through a relationship.
var byTransactionId: [UUID: [LineItem]] {
return Dictionary(grouping: self) { item in
item.transaction?.id ?? UUID()
}
}
In this case, the transaction has been deleted, but the relationship existed when the fetch occurred, so the transaction value is non-nil. The crash occurs when accessing the id. This is the error.
SwiftData/BackingData.swift:1035: Fatal error: This model instance was invalidated because its backing data could no longer be found the store. PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(backing: SwiftData.PersistentIdentifier.PersistentIdentifierBacking.managedObjectID(0xb43fea2c4bc3b3f5 <x-coredata://A9EFB8E3-CB47-48B2-A7C4-6EEA25D27E2E/Transaction/p1756>)))
I see other posts about this error and am exploring some suggestions, but if anyone has any thoughts, they would be appreciated.
I am following Apple's instruction to sync SwiftData with CloudKit. While initiating the ModelContainer, right after removing the store from Core Data, the error occurs:
FAULT: NSInternalInconsistencyException: This NSPersistentStoreCoordinator has no persistent stores (unknown). It cannot perform a save operation.; (user info absent)
I've tried removing default.store and its related files/folders before creating the ModelContainer with FileManager but it does not resolve the issue. Isn't it supposed to create a new store when the ModelContainer is initialized? I don't understand why this error occurs. Error disappears when I comment out the #if DEBUG block.
Code:
import CoreData
import SwiftData
import SwiftUI
struct InitView: View {
@Binding var modelContainer: ModelContainer?
@Binding var isReady: Bool
@State private var loadingDots = ""
@State private var timer: Timer?
var body: some View {
VStack(spacing: 16) {
Text("Loading\(loadingDots)")
.font(.title2)
.foregroundColor(.gray)
}
.padding()
.onAppear {
startAnimation()
registerTransformers()
let config = ModelConfiguration()
let newContainer: ModelContainer
do {
#if DEBUG
// Use an autorelease pool to make sure Swift deallocates the persistent
// container before setting up the SwiftData stack.
try autoreleasepool {
let desc = NSPersistentStoreDescription(url: config.url)
let opts = NSPersistentCloudKitContainerOptions(containerIdentifier: "iCloud.my-container-identifier")
desc.cloudKitContainerOptions = opts
// Load the store synchronously so it completes before initializing the
// CloudKit schema.
desc.shouldAddStoreAsynchronously = false
if let mom = NSManagedObjectModel.makeManagedObjectModel(for: [Page.self]) {
let container = NSPersistentCloudKitContainer(name: "Pages", managedObjectModel: mom)
container.persistentStoreDescriptions = [desc]
container.loadPersistentStores { _, err in
if let err {
fatalError(err.localizedDescription)
}
}
// Initialize the CloudKit schema after the store finishes loading.
try container.initializeCloudKitSchema()
// Remove and unload the store from the persistent container.
if let store = container.persistentStoreCoordinator.persistentStores.first {
try container.persistentStoreCoordinator.remove(store)
}
}
// let fileManager = FileManager.default
// let sqliteURL = config.url
// let urls: [URL] = [
// sqliteURL,
// sqliteURL.deletingLastPathComponent().appendingPathComponent("default.store-shm"),
// sqliteURL.deletingLastPathComponent().appendingPathComponent("default.store-wal"),
// sqliteURL.deletingLastPathComponent().appendingPathComponent(".default_SUPPORT"),
// sqliteURL.deletingLastPathComponent().appendingPathComponent("default_ckAssets")
// ]
// for url in urls {
// try? fileManager.removeItem(at: url)
// }
}
#endif
newContainer = try ModelContainer(for: Page.self,
configurations: config) // ERROR!!!
} catch {
fatalError(error.localizedDescription)
}
modelContainer = newContainer
isReady = true
}
.onDisappear {
stopAnimation()
}
}
private func startAnimation() {
timer = Timer.scheduledTimer(
withTimeInterval: 0.5,
repeats: true
) { _ in
updateLoadingDots()
}
}
private func stopAnimation() {
timer?.invalidate()
timer = nil
}
private func updateLoadingDots() {
if loadingDots.count > 2 {
loadingDots = ""
} else {
loadingDots += "."
}
}
}
import CoreData
import SwiftData
import SwiftUI
@main
struct MyApp: App {
@State private var modelContainer: ModelContainer?
@State private var isReady: Bool = false
var body: some Scene {
WindowGroup {
if isReady, let modelContainer = modelContainer {
ContentView()
.modelContainer(modelContainer)
} else {
InitView(modelContainer: $modelContainer, isReady: $isReady)
}
}
}
}
I'm writing some tests to confirm the behavior of my app. White creating a model actor to delete objects I realized that ModelContext.model(for:) does return objects that are deleted. I was able to reproduces this with this minimal test case:
@Model class Activity {
init() {}
}
struct MyLibraryTests {
let modelContainer = try! ModelContainer(
for: Activity.self,
configurations: ModelConfiguration(
isStoredInMemoryOnly: true
)
)
init() throws {
let context = ModelContext(modelContainer)
context.insert(Activity())
try context.save()
}
@Test func modelForIdAfterDelete() async throws {
let context = ModelContext(modelContainer)
let id = try context.fetch(FetchDescriptor<Activity>()).first!.id
context.delete(context.model(for: id) as! Activity)
try context.save()
let result = context.model(for: id) as? Activity
#expect(result == nil) // Expectation failed: (result → MyLibrary.Activity) == nil
}
@Test func fetchDescriptorAfterDelete() async throws {
let context = ModelContext(modelContainer)
let id = try context.fetch(FetchDescriptor<Activity>()).first!.id
context.delete(context.model(for: id) as! Activity)
try context.save()
let result = try context.fetch(
FetchDescriptor<Activity>(predicate: #Predicate { $0.id == id })
).first
#expect(result == nil)
}
}
Here I create a new context, insert an model and save it.
The test modelForIdAfterDelete does fail, as result still contains the deleted object.
I also tried to check #expect(result!.isDeleted), but it is also false.
With the second test I use a FetchDescriptor to retrieve the object by ID and it correctly returns nil.
Shouldn't both methods use a consistent behavior?
I'm using SwiftData, and I'm using iCloud's CloudKit feature to back up my data.
The problem here is that once you start backing up your data, you can't erase it completely.
Even if the user adds 4 data and erases 4 again, I'm using about 2.5kb.
I don't know how the user using the app will accept this.
I'm trying to provide the user with the ability to erase data at once, what should I do??
Topic:
App & System Services
SubTopic:
iCloud & Data
Tags:
CloudKit
Cloud and Local Storage
iCloud Drive
SwiftData
Hi, I am building an iOS app with SwiftUI and SwiftData for the first time and I am experiencing a lot of difficulty with this error:
Thread 44: Fatal error: Never access a full future backing data - PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(backing: SwiftData.PersistentIdentifier.PersistentIdentifierBacking.managedObjectID(<ID> <x-coredata://<UUID>/MySwiftDataModel/p1>)), backing: SwiftData.PersistentIdentifier.PersistentIdentifierBacking.managedObjectID(<ID> <x-coredata://<UUID>/MySwiftDataModel/p1>)) with Optional(<UUID>)
I have been trying to figure out what the problem is, but unfortunately I cannot find any information in the documentation or on other sources online. My only theory about this error is that it is somehow related to fetching an entity that has been created in-memory, but not yet saved to the modelContext in SwiftData.
However, when I am trying to debug this, it's not clear this is the case. Sometimes the error happens, sometimes it doesn't. Saving manually does not always solve the error.
Therefore, it would be extremely helpful if someone could explain what this error means and whether there are any best practices to do with SwiftData, or some pitfalls to avoid (such as wrapping my model context into a repository class).
To be clear, this problem is NOT related to one area of my code, it happens throughout my app, at unpredictable places and time. Given that there is very little information related to this error, I am at a loss at how to make sure that this never happens.
This question has been asked on the forum here as well as on StackOverflow, Reddit (can't link that here), but none of the answers worked for me.
For reference, my models generally look like this:
import Foundation
import SwiftData
@Model
final class MySwiftDataModel {
// Stable cross-device identity
@Attribute(.unique)
var uuid: UUID
var someNumber: Int
var someString: String
@Relationship(deleteRule: .nullify, inverse: \AnotherSwiftDataModel.parentModel)
var childModels: [AnotherSwiftDataModel]
init(uuid: UUID = UUID(), someNumber: Int = 1, someString: String = "Some", childModels: [AnotherSwiftDataModel] = []) {
self.uuid = uuid
self.someNumber = someNumber
self.someString = someString
self.childModels = childModels
}
func addChildModel(model: AnotherSwiftDataModel) {
self.childModels.append(model)
}
func removeChildModel(by id: PersistentIdentifier) {
self.childModels = self.childModels.filter { $0.id != id }
}
}
and the child model:
import Foundation
import SwiftData
@Model
final class AnotherSwiftDataModel {
// Stable cross-device identity
@Attribute(.unique)
var uuid: UUID
var someNumber: Int
var someString: String
var parentModel: MySwiftDataModel?
init(uuid: UUID = UUID(), someNumber: Int = 1, someString: String = "Some") {
self.uuid = uuid
self.someNumber = someNumber
self.someString = someString
}
}
For now, you can assume I am not using CloudKit - i know for a fact the error is unrelated to CloudKit, because it happens when I am not using CloudKit (so I do not need to follow CloudKit's requirements for model design, such as nullable values etc).
As I said, the error surfaces at different times - sometimes during assignments, a lot of times during deletions of related models, etc.
Could you please explain what I am doing wrong and how I can make sure that this error does not happen? What are the architectural patterns that work best for SwiftData in this case? Do you have any examples of things I should avoid?
Thanks
I get this message when trying to save my Models.
CoreData: error: SQLCore dispatchRequest: exception handling request: <NSSQLSaveChangesRequestContext: 0x303034540> , I/O error for database at /var/mobile/Containers/Data/Application/726ECA8C-6C67-4BFE-89E7-AFD8A83CAA5D/Library/Application Support/default.store. SQLite error code:1, 'no such table: ZCALENDARMODEL' with userInfo of {
NSFilePath = "/var/mobile/Containers/Data/Application/726ECA8C-6C67-4BFE-89E7-AFD8A83CAA5D/Library/Application Support/default.store";
NSSQLiteErrorDomain = 1;
}
SwiftData.DefaultStore save failed with error: Error Domain=NSCocoaErrorDomain Code=256 "The file “default.store” couldn’t be opened." UserInfo={NSFilePath=/var/mobile/Containers/Data/Application/726ECA8C-6C67-4BFE-89E7-AFD8A83CAA5D/Library/Application Support/default.store, NSSQLiteErrorDomain=1}
The App has Recipes and Calendars and the user can select a Recipe for each Calendar day. The recipe should not be referenced, it should be saved by SwiftData along with the Calendar.
import SwiftUI
import SwiftData
enum CalendarSource: String, Codable {
case created
case imported
}
@Model
class CalendarModel: Identifiable, Codable {
var id: UUID = UUID()
var name: String
var startDate: Date
var endDate: Date
var recipes: [String: RecipeData] = [:]
var thumbnailData: Data?
var source: CalendarSource?
// Computed Properties
var daysBetween: Int {
let days = Calendar.current.dateComponents([.day], from: startDate.midnight, to: endDate.midnight).day ?? 0
return days + 1
}
var allDates: [Date] {
startDate.midnight.allDates(upTo: endDate.midnight)
}
var thumbnailImage: Image? {
if let data = thumbnailData, let uiImage = UIImage(data: data) {
return Image(uiImage: uiImage)
} else {
return nil
}
}
// Initializer
init(name: String, startDate: Date, endDate: Date, thumbnailData: Data? = nil, source: CalendarSource? = .created) {
self.name = name
self.startDate = startDate
self.endDate = endDate
self.thumbnailData = thumbnailData
self.source = source
}
// Convenience initializer to create a copy of an existing calendar
static func copy(from calendar: CalendarModel) -> CalendarModel {
let copiedCalendar = CalendarModel(
name: calendar.name,
startDate: calendar.startDate,
endDate: calendar.endDate,
thumbnailData: calendar.thumbnailData,
source: calendar.source
)
// Copy recipes
copiedCalendar.recipes = calendar.recipes.mapValues { $0 }
return copiedCalendar
}
// Codable Conformance
private enum CodingKeys: String, CodingKey {
case id, name, startDate, endDate, recipes, thumbnailData, source
}
required init(from decoder: Decoder) throws {
let container = try decoder.container(keyedBy: CodingKeys.self)
id = try container.decode(UUID.self, forKey: .id)
name = try container.decode(String.self, forKey: .name)
startDate = try container.decode(Date.self, forKey: .startDate)
endDate = try container.decode(Date.self, forKey: .endDate)
recipes = try container.decode([String: RecipeData].self, forKey: .recipes)
thumbnailData = try container.decodeIfPresent(Data.self, forKey: .thumbnailData)
source = try container.decodeIfPresent(CalendarSource.self, forKey: .source)
}
func encode(to encoder: Encoder) throws {
var container = encoder.container(keyedBy: CodingKeys.self)
try container.encode(id, forKey: .id)
try container.encode(name, forKey: .name)
try container.encode(startDate, forKey: .startDate)
try container.encode(endDate, forKey: .endDate)
try container.encode(recipes, forKey: .recipes)
try container.encode(thumbnailData, forKey: .thumbnailData)
try container.encode(source, forKey: .source)
}
}
import SwiftUI
struct RecipeData: Codable, Identifiable {
var id: UUID = UUID()
var name: String
var ingredients: String
var steps: String
var thumbnailData: Data?
// Computed property to convert thumbnail data to a SwiftUI Image
var thumbnailImage: Image? {
if let data = thumbnailData, let uiImage = UIImage(data: data) {
return Image(uiImage: uiImage)
} else {
return nil // No image
}
}
init(recipe: RecipeModel) {
self.name = recipe.name
self.ingredients = recipe.ingredients
self.steps = recipe.steps
self.thumbnailData = recipe.thumbnailData
}
}
import SwiftUI
import SwiftData
@Model
class RecipeModel: Identifiable, Codable {
var id: UUID = UUID()
var name: String
var ingredients: String
var steps: String
var thumbnailData: Data? // Store the image data for the thumbnail
static let fallbackSymbols = ["book.pages.fill", "carrot.fill", "fork.knife", "stove.fill"]
// Computed property to convert thumbnail data to a SwiftUI Image
var thumbnailImage: Image? {
if let data = thumbnailData, let uiImage = UIImage(data: data) {
return Image(uiImage: uiImage)
} else {
return nil // No image
}
}
// MARK: - Initializer
init(name: String, ingredients: String = "", steps: String = "", thumbnailData: Data? = nil) {
self.name = name
self.ingredients = ingredients
self.steps = steps
self.thumbnailData = thumbnailData
}
// MARK: - Copy Function
func copy() -> RecipeModel {
RecipeModel(
name: self.name,
ingredients: self.ingredients,
steps: self.steps,
thumbnailData: self.thumbnailData
)
}
// MARK: - Codable Conformance
private enum CodingKeys: String, CodingKey {
case id, name, ingredients, steps, thumbnailData
}
required init(from decoder: Decoder) throws {
...
}
func encode(to encoder: Encoder) throws {
var container = encoder.container(keyedBy: CodingKeys.self)
try container.encode(id, forKey: .id)
try container.encode(name, forKey: .name)
try container.encode(ingredients, forKey: .ingredients)
try container.encode(steps, forKey: .steps)
try container.encode(thumbnailData, forKey: .thumbnailData)
}
}
I have been recently getting the following error seemingly randomly, when an event handler of a SwiftUI view accesses a relationship of a SwiftData model the view holds a reference to. I haven't yet found a reliable way of reproducing it:
SwiftData/BackingData.swift:866: Fatal error: This model instance was invalidated
because its backing data could no longer be found the store.
PersistentIdentifier(id: SwiftData.PersistentIdentifier.ID(url: COREDATA_ID_URL),
implementation: SwiftData.PersistentIdentifierImplementation)
What could cause this error? Could you suggest me a workaround?
I'm experiencing a significant UI freeze in my SwiftUI app that uses SwiftData with CloudKit sync. When users tap a button to present a sheet for the first time after app launch, the entire UI becomes unresponsive for 5-10 seconds. Subsequent sheet presentations work fine.
App Architecture
Service layer: An @Observable class marked with @MainActor that orchestrates operations
Persistence layer: A @ModelActor class that handles SwiftData operations
SwiftUI views: Using @Environment to access the service layer
The structure looks like this:
@Observable
@MainActor
final class MyServices {
let persistence: DataPersistence
init(modelContainer: ModelContainer) {
self.persistence = DataPersistence(modelContainer: modelContainer)
}
func addItem(title: String) async {
// Creates and saves an item through persistence layer
}
}
@ModelActor
actor DataPersistence {
func saveItem(_ item: Item) async {
// Save to SwiftData
}
}
The app initializes the ModelContainer at the Scene level and passes it through the environment:
@main
struct MyApp: App {
let container = ModelContainer(for: Item.self)
var body: some Scene {
WindowGroup {
ContentView()
.modelContainer(container)
.environment(MyServices(modelContainer: container))
}
}
}
The Problem
When a user taps the "Add Item" button which presents a sheet:
Button("Add Item") {
showingAddSheet = true
}
.sheet(isPresented: $showingAddSheet) {
AddItemView(onAdd: { title in
await services.addItem(title: title)
})
}
The UI freezes completely for 5-10 seconds on first presentation. During this time:
The button remains in pressed state
No UI interactions work
The app appears completely frozen
After the freeze, the sheet opens and everything works normally
This only happens on the first sheet presentation after app launch. I suspect it's related to SwiftData's ModelContext initialization happening on the main thread despite using @ModelActor, but I'm not sure why this would happen given that ModelActor should handle background execution.
Environment
iOS 18
SwiftData with CloudKit sync enabled
Xcode 16
Swift 6
Has anyone experienced similar freezes with SwiftData and @ModelActor? Is there something wrong with how I'm structuring the initialization of these components? The documentation suggests @ModelActor should handle background operations automatically, but the freeze suggests otherwise.
Any insights would be greatly appreciated!
I want to get to a point where I can use a small view with a query for my SwiftData model like this:
@Query
private var currentTrainingCycle: [TrainingCycle]
init(/*currentDate: Date*/) {
_currentTrainingCycle = Query(filter: #Predicate<TrainingCycle> {
$0.numberOfDays > 0
// $0.startDate < currentDate && currentDate < $0.endDate
}, sort: \.startDate)
}
The commented code is where I want to go. In this instance, it'd be created as a lazy var in a viewModel to have it stable (and not constantly re-creating the view). Since it was not working, I thought I could check the same view with a query that does not require any dynamic input. In this case, the numberOfDays never changes after instantiation.
But still, each time the app tries to create this view, the app becomes unresponsive, the CPU usage goes at 196%, memory goes way high and the device heats up quickly.
Am I holding it wrong? How can I have a dynamic predicate on a View in SwiftUI with SwiftData?
Hi there, I got two models here:
Two Models, with Many-To-Many Relationship
@Model
final class PresetParams: Identifiable {
@Attribute(.unique) var id: UUID = UUID()
var positionX: Float = 0.0
var positionY: Float = 0.0
var positionZ: Float = 0.0
var volume: Float = 1.0
@Relationship(deleteRule: .nullify, inverse: \Preset.presetAudioParams)
var preset = [Preset]()
init(position: SIMD3<Float>, volume: Float) {
self.positionX = position.x
self.positionY = position.y
self.positionZ = position.z
self.volume = volume
self.preset = []
}
var position: SIMD3<Float> {
get {
return SIMD3<Float>(x: positionX, y: positionY, z: positionZ)
}
set {
positionX = newValue.x
positionY = newValue.y
positionZ = newValue.z
}
}
}
@Model
final class Preset: Identifiable {
@Attribute(.unique) var id: UUID = UUID()
var presetName: String
var presetDesc: String?
var presetAudioParams = [PresetParams]() // Many-To-Many Relationship.
init(presetName: String, presetDesc: String? = nil) {
self.presetName = presetName
self.presetDesc = presetDesc
self.presetAudioParams = []
}
}
To be honest, I don't fully understand how the @Relationship thing works properly in a Many-To-Many relationship situation. Some tutorials suggest that it's required on the "One" side of an One-To-Many Relationship, while the "Many" side doesn't need it.
And then there is an ObservableObject called "ModelActors" to manage all ModelActors, ModelContainer, etc.
ModelActors, ModelContainer...
class ModelActors: ObservableObject {
static let shared: ModelActors = ModelActors()
let sharedModelContainer: ModelContainer
private init() {
var schema = Schema([
// ...
Preset.self,
PresetParams.self,
// ...
])
do {
sharedModelContainer = try ModelContainer(for: schema, migrationPlan: MigrationPlan.self)
} catch {
fatalError("Could not create ModelContainer: \(error.localizedDescription)")
}
}
}
And there is a migrationPlan:
MigrationPlan
// MARK: V102
// typealias ...
// MARK: V101
typealias Preset = AppSchemaV101.Preset
typealias PresetParams = AppSchemaV101.PresetParams
// MARK: V100
// typealias ...
enum MigrationPlan: SchemaMigrationPlan {
static var schemas: [VersionedSchema.Type] {
[
AppSchemaV100.self,
AppSchemaV101.self,
AppSchemaV102.self,
]
}
static var stages: [MigrationStage] {
[AppMigrateV100toV101, AppMigrateV101toV102]
}
static let AppMigrateV100toV101 = MigrationStage.lightweight(fromVersion: AppSchemaV100.self, toVersion: AppSchemaV101.self)
static let AppMigrateV101toV102 = MigrationStage.lightweight(fromVersion: AppSchemaV101.self, toVersion: AppSchemaV102.self)
}
// MARK: Here is the AppSchemaV101
enum AppSchemaV101: VersionedSchema {
static var versionIdentifier: Schema.Version = Schema.Version(1, 0, 1)
static var models: [any PersistentModel.Type] {
return [ // ...
Preset.self,
PresetParams.self
]
}
}
Fails on iOS 18.3.x: "Failed to fulfill link PendingRelationshipLink"
So I expected the SwiftData subsystem to work correctly with version control. A good news is that on iOS 18.1 it does work. But it fails on iOS 18.3.x with a fatal Error:
"SwiftData/SchemaCoreData.swift:581: Fatal error: Failed to fulfill link PendingRelationshipLink(relationshipDescription: (<NSRelationshipDescription: 0x30377fe80>), name preset, isOptional 0, isTransient 0, entity PresetParams, renamingIdentifier preset, validation predicates (), warnings (), versionHashModifier (null)userInfo {}, destination entity Preset, inverseRelationship (null), minCount 0, maxCount 0, isOrdered 0, deleteRule 1, destinationEntityName: "Preset", inverseRelationshipName: Optional("presetAudioParams")), couldn't find inverse relationship 'Preset.presetAudioParams' in model"
Fails on iOS 17.5: Another Error
I tested it on iOS 17.5 and found another issue: Accessing or mutating the "PresetAudioParams" property causes the SwiftData Macro Codes to crash, affecting both Getter and Setter. It fails with an error:
"EXC_BREAKPOINT (code=1, subcode=0x1cc1698ec)"
Tweaking the @Relationship marker and ModelContainer settings didn't fix the problem.
My macOS app is developed using SwfitUI, SwiftData, and CloudKit. In the development environment, CloudKit works well. Locally added models can be quickly viewed in the CloudKit Console. macOS app and iOS app with the same BundleID can also synchronize data normally when developing locally. However, in the production environment, the macOS app cannot synchronize data with iCloud. But iOS app can. The models added in the production environment are only saved locally and cannot be viewed in CloudKit Console Production.
I am sure I have configured correctly, container schema changes to deploy to the Production environment. I think there may be a problem with CloudKit in macOS.
Please help troubleshoot the problem. I can provide you with any information you need.
var body: some Scene {
WindowGroup {
MainView()
.frame(minWidth: 640, minHeight: 480)
.environment(mainViewModel)
}
.modelContainer(for: [NoteRecord.self])
}
I didn't do anything special. I didn’t do anything special. I just used SwiftData hosted by CloudKit.
Xcode 16.2 (16C5032a)
FB16300857
Consider the following SwiftData model objects (only the relevant portions are shown) (note that all relationships are optional because eventually this app will use CloudKit):
@Model
final public class Team {
public var animal: Animal?
public var handlers: [Handler]?
...
}
@Model
final public class Animal {
public var callName: String
public var familyName: String
@Relationship(inverse: \Team.animal) public var teams: [Team]?
...
}
@Model
final public class Handler {
public var givenName: String
@Relationship(inverse: \Team.handlers) public var teams: [Team]?
}
Now I want to display Team records in a list view, sorted by animal.familyName, animal.callName, and handlers.first.givenName.
The following code crashes:
struct TeamListView: View {
@Query<Team>(sort: [SortDescriptor(\Team.animal?.familyName),
SortDescriptor(\Team.animal?.callName),
SortDescriptor(\Team.handlers?.first?.givenName)]) var teams : [Team]
var body: some View {
List {
ForEach(teams) { team in
...
}
}
}
}
However, if I remove the sort clause from the @Query and do the sort explicitly, the code appears to work (at least in preliminary testing):
struct TeamListView: View {
@Query<Team> var teams: [Team]
var body: some View {
let sortedTeams = sortResults()
List {
ForEach(sortedTeams) { team in
...
}
}
}
private func sortResults() -> [Team] {
let results: [Team] = teams.sorted { team1, team2 in
let fam1 = team1.animal?.familyName ?? ""
let fam2 = team2.animal?.familyName ?? ""
let comp1 = fam1.localizedCaseInsensitiveCompare(fam2)
if comp1 == .orderedAscending { return true }
if comp1 == .orderedDescending { return false }
... <proceed to callName and (if necessary) handler givenName comparisons> ...
}
}
}
While I obviously have a workaround, this is (in my mind) a serious weakness in the implementation of the Query macro.
Hi,
I am currently developing a document-based application for macOS and have encountered a challenge related to document container management. Specifically, I need to open a windowGroup that shares the same container as the one used in the DocumentGroup. However, my current approach of using a global shared model container has led to unintended behavior: any new document created is linked to existing ones, and changes made in one document are reflected across all documents.
To address this issue, I am looking for a solution that allows each newly created document to be individualized while still sharing the document container with all relevant WindowGroups that require access to the data it holds. I would greatly appreciate any insights or recommendations you might have on how to achieve this.
Thank you for your time and assistance.
Best regards,
Something like:
@main
struct Todo: App {
var body: some Scene {
DocumentGroup(editing: Item.self, contentType: .item) {
ContentView()
}
WindowGroup {
UndockView()
.modelContainer(of documentGroup above)
}
}
}
The Java Swing and AWT MVC model made it easy to develop complex UIs with data interactions that were not described readily in a nested layer that SwiftUI demands. The implicit update model of SwiftUI greatly complicates development of applications that often requires nested components to have to know too much about other components and other structures than their own, because button events and other user interactions cannot readily alter state across layers. A button push on one component then has to be knowledgable about state in other components which have to have that state represented as @State or @Binding etc. and this causes all kinds of wiring to be spread all over the place rather than have a more centralized "state management function" that would be able to look at the world and synchronize the UIs state across changes.
The fact that the compiler get's lost in the weeds when types and signatures don't match in deeper component structures doesn't help because it makes it doubly hard to do refactoring to raise and lower state management within the structure readily, because the compiler just cannot simply tell you that a function or constructor signature is no longer correct.
Hello,
I am trying to get the elements from my SwiftData databse in the configuration for my widget.
The SwiftData model is the following one:
@Model
class CountdownEvent {
@Attribute(.unique) var id: UUID
var title: String
var date: Date
@Attribute(.externalStorage) var image: Data
init(id: UUID, title: String, date: Date, image: Data) {
self.id = id
self.title = title
self.date = date
self.image = image
}
}
And, so far, I have tried the following thing:
AppIntent.swift
struct ConfigurationAppIntent: WidgetConfigurationIntent {
static var title: LocalizedStringResource { "Configuration" }
static var description: IntentDescription { "This is an example widget." }
// An example configurable parameter.
@Parameter(title: "Countdown")
var countdown: CountdownEntity?
}
Countdowns.swift, this is the file with the widget view
struct Provider: AppIntentTimelineProvider {
func placeholder(in context: Context) -> SimpleEntry {
SimpleEntry(date: Date(), configuration: ConfigurationAppIntent())
}
func snapshot(for configuration: ConfigurationAppIntent, in context: Context) async -> SimpleEntry {
SimpleEntry(date: Date(), configuration: configuration)
}
func timeline(for configuration: ConfigurationAppIntent, in context: Context) async -> Timeline<SimpleEntry> {
var entries: [SimpleEntry] = []
// Generate a timeline consisting of five entries an hour apart, starting from the current date.
let currentDate = Date()
for hourOffset in 0 ..< 5 {
let entryDate = Calendar.current.date(byAdding: .hour, value: hourOffset, to: currentDate)!
let entry = SimpleEntry(date: entryDate, configuration: configuration)
entries.append(entry)
}
return Timeline(entries: entries, policy: .atEnd)
}
// func relevances() async -> WidgetRelevances<ConfigurationAppIntent> {
// // Generate a list containing the contexts this widget is relevant in.
// }
}
struct SimpleEntry: TimelineEntry {
let date: Date
let configuration: ConfigurationAppIntent
}
struct CountdownsEntryView : View {
var entry: Provider.Entry
var body: some View {
VStack {
Text("Time:")
Text(entry.date, style: .time)
Text("Title:")
Text(entry.configuration.countdown?.title ?? "Default")
}
}
}
struct Countdowns: Widget {
let kind: String = "Countdowns"
var body: some WidgetConfiguration {
AppIntentConfiguration(kind: kind, intent: ConfigurationAppIntent.self, provider: Provider()) { entry in
CountdownsEntryView(entry: entry)
.containerBackground(.fill.tertiary, for: .widget)
}
}
}
CountdownEntity.swift, the file for the AppEntity and EntityQuery structs
struct CountdownEntity: AppEntity, Identifiable {
var id: UUID
var title: String
var date: Date
var image: Data
var displayRepresentation: DisplayRepresentation {
DisplayRepresentation(title: "\(title)")
}
static var defaultQuery = CountdownQuery()
static var typeDisplayRepresentation: TypeDisplayRepresentation = "Countdown"
init(id: UUID, title: String, date: Date, image: Data) {
self.id = id
self.title = title
self.date = date
self.image = image
}
init(id: UUID, title: String, date: Date) {
self.id = id
self.title = title
self.date = date
self.image = Data()
}
init(countdown: CountdownEvent) {
self.id = countdown.id
self.title = countdown.title
self.date = countdown.date
self.image = countdown.image
}
}
struct CountdownQuery: EntityQuery {
typealias Entity = CountdownEntity
static var typeDisplayRepresentation = TypeDisplayRepresentation(name: "Countdown Event")
static var defaultQuery = CountdownQuery()
@Environment(\.modelContext) private var modelContext // Warning here: Stored property '_modelContext' of 'Sendable'-conforming struct 'CountdownQuery' has non-sendable type 'Environment<ModelContext>'; this is an error in the Swift 6 language mode
func entities(for identifiers: [UUID]) async throws -> [CountdownEntity] {
let countdownEvents = getAllEvents(modelContext: modelContext)
return countdownEvents.map { event in
return CountdownEntity(id: event.id, title: event.title, date: event.date, image: event.image)
}
}
func suggestedEntities() async throws -> [CountdownEntity] {
// Return some suggested entities or an empty array
return []
}
}
CountdownsManager.swift, this one just has the function that gets the array of countdowns
func getAllEvents(modelContext: ModelContext) -> [CountdownEvent] {
let descriptor = FetchDescriptor<CountdownEvent>()
do {
let allEvents = try modelContext.fetch(descriptor)
return allEvents
}
catch {
print("Error fetching events: \(error)")
return []
}
}
I have installed it in my phone and when I try to edit the widget, it doesn't show me any of the elements I have created in the app, just a loading dropdown for half a second:
What am I missing here?
Topic:
App & System Services
SubTopic:
Widgets & Live Activities
Tags:
SwiftUI
WidgetKit
App Intents
SwiftData