When deleting the last added item from a list view in my app a bar chart in a different view crashes my app. If I delete any other item in the list view everything work as expected. I'm using SwiftData in my app. Does anyone have any idea how I can prevent the app from crashing? I filter the data in the init to only have the current days data Chart View struct ConsumedDrinkChartView: View { @Environment(\.modelContext) var modelContext let screenVerticalSizeClass = UIScreen.VerticalSizeClass var compactScreen: Bool { return screenVerticalSizeClass == "compact" } @State private var chartCalendarUnit: Calendar.Component = .hour @State private var chartRange: ClosedRange<Date> @State private var axisValueLabelFormat: Date.FormatStyle @State private var axisValueLabelCount: Int @State private var startDate: Date @State private var endDate: Date @State private var plotStartPadding: Double = 0 @State private var plotEndPadding: Double = 0 @Binding var selectedTimeFrame:String @Query var consumedFluids: [ConsumedDrink] let defaultVolume = DataStore.defaultVolume init(selectedTimeFrame: Binding<String>, dateRange: ClosedRange<Date>) { _selectedTimeFrame = selectedTimeFrame _startDate = State(initialValue: Date().startOfDay) _endDate = State(initialValue: Date().endOfDay) let endDate = dateRange.upperBound let startDate = dateRange.lowerBound _consumedFluids = Query(filter: #Predicate { $0.date > startDate && $0.date < endDate }, sort: \ConsumedDrink.date) _chartRange = State(initialValue: dateRange) _axisValueLabelFormat = State(initialValue: .dateTime.hour(.conversationalDefaultDigits(amPM: .narrow))) _axisValueLabelCount = State(initialValue: 2) } var body: some View { Chart { ForEach(consumedFluids) { consumedFluid in BarMark(x: .value("Date", consumedFluid.date, unit: chartCalendarUnit), y: .value("Fluid Ounces", consumedFluid.drink.amount)) } .foregroundStyle(.pink) } .frame(height: 180) .padding() .chartXAxis { AxisMarks(values: .stride(by: chartCalendarUnit, count: axisValueLabelCount,roundLowerBound: true, roundUpperBound: true)) { _ in AxisGridLine() AxisValueLabel(format: axisValueLabelFormat, centered: true) } } .chartXScale(domain: chartRange, range: .plotDimension(startPadding: plotStartPadding, endPadding: plotEndPadding)) .background(RoundedRectangle(cornerRadius: 12).fill(Color(.secondarySystemBackground))) .onChange(of: selectedTimeFrame) { selectChartRange() } .onChange(of: consumedFluids) { print("consumedFluids: \(consumedFluids.count)") } .onAppear { selectChartRange() } } func selectChartRange() { plotStartPadding = 0 plotEndPadding = 0 switch selectedTimeFrame { case "Day": startDate = Date().startOfDay endDate = Date().endOfDay chartCalendarUnit = .hour axisValueLabelCount = 2 axisValueLabelFormat = .dateTime.hour(.conversationalDefaultDigits(amPM: .narrow)) case "Week": startDate = Date().add(days: -7) chartCalendarUnit = .day axisValueLabelCount = 1 axisValueLabelFormat = .dateTime.weekday() case "Month": startDate = Date().add(days: -30) chartCalendarUnit = .day axisValueLabelCount = 2 axisValueLabelFormat = .dateTime.day() plotStartPadding = 10 plotEndPadding = 10 case "SixMonths": let endOfMonth = Date().endOfMonth() startDate = endOfMonth.add(months: -6) chartCalendarUnit = .month axisValueLabelCount = 1 axisValueLabelFormat = .dateTime.month() plotStartPadding = 10 plotEndPadding = 32 case "Year": let endOfMonth = Date().endOfMonth() startDate = endOfMonth.add(months: -12) chartCalendarUnit = .month axisValueLabelCount = 1 axisValueLabelFormat = .dateTime.month(.narrow) plotStartPadding = 15 plotEndPadding = 15 default: chartCalendarUnit = .day } chartRange = startDate...endDate } } List View struct ConsumedDrinkListView: View { @Environment(\.modelContext) var modelContext @Query(sort: \ConsumedDrink.date) var dailyConsumedFluids: [ConsumedDrink] @State private var showingAlert = false @State private var alertMessage: String = "" @State private var alertTitle: String = "" var body: some View { NavigationStack { if dailyConsumedFluids.isEmpty { ContentUnavailableView("No Consumed Drinks", systemImage: "mug.fill", description: Text("Drink some water and stay hydrated.")) } else { List { ForEach(dailyConsumedFluids, id: \.self) { consumedDrink in NavigationLink { EditConsumedDrinkView(consumedDrink: consumedDrink) } label: { ConsumedDrinkRowView(consumedDrink: consumedDrink) } .swipeActions{ Button("Delete", systemImage: "trash", role: .destructive) { deleteConsumedDrink(consumedDrink: consumedDrink) } .tint(.red) } } } .listStyle(.plain) .alert(isPresented: $showingAlert) { Alert(title: Text(alertTitle), message: Text(alertMessage), dismissButton: .default(Text("OK")) ) } } Text("") .navigationTitle("Consumed Drinks") .navigationBarTitleDisplayMode(.inline) } } func deleteConsumedDrink(consumedDrink: ConsumedDrink) { do { if modelContext.hasChanges { print("ConsumedDrinkListView.deleteConsumedDrink") print("modelContext has Changes. Saving modelContext") try modelContext.save() } try DataStore.deleteConsumedDrink(drink: consumedDrink, modelContext: modelContext) } catch { self.alertTitle = "Error deleting consumed drink - \(consumedDrink.drink.name)" self.alertMessage = error.localizedDescription self.showingAlert = true } } }

The exact error is: Unable to create bundle at URL (file:///System/Library/CoreServices/SystemVersion.bundle): does not exist or not a directory (0).

SwiftData offers a #Unique macro as of iOS 18, see here: https://developer.apple.com/documentation/swiftdata/unique(_:) I was wondering if that one might work when the DB is backed by CloudKit.

Hi, I've been working on an app that - so far - has only had to deal with offline data store. The usage is fairly simple: the user picks their favourite tv shows and networks, and they get persisted with SwiftData with all the correct relationships. Now, I would like to migrate the local storage of the users to a private CloudKit db, but every time I upgrade the app, the data seems to disappear completely. This is the snippet evolved through the attempt of migrating the data: Current Production code public static func makeModelContainer() -> ModelContainer { do { let processRequiresInMemory = ProcessInfo.processInfo.arguments.contains("inMemoryDatabasePreferred") let modelConfiguration = ModelConfiguration( isStoredInMemoryOnly: processRequiresInMemory, groupContainer: .automatic, cloudKitDatabase: .none ) let modelContainer = try ModelContainer( for: Country.self, Episode.self, Movie.self, Season.self, Show.self, Network.self, NetworkSubscription.self, migrationPlan: AppModelMigrationPlan.self, configurations: modelConfiguration ) return modelContainer } catch { fatalError("Could not initialize model container") } } Testing CloudKit enabled public static func makeModelContainer() -> ModelContainer { do { let processRequiresInMemory = ProcessInfo.processInfo.arguments.contains("inMemoryDatabasePreferred") let modelConfiguration = ModelConfiguration( "synced", isStoredInMemoryOnly: processRequiresInMemory, groupContainer: .automatic, cloudKitDatabase: .automatic ) let modelContainer = try ModelContainer( for: Country.self, Episode.self, Movie.self, Season.self, Show.self, Network.self, NetworkSubscription.self, migrationPlan: AppModelMigrationPlan.self, configurations: modelConfiguration ) return modelContainer } catch { fatalError("Could not initialize model container") } } } The differences, which I don't understand fully because I could not find documentation, are: ModelContainer(...) -> ModelContainer("synced", ...) cloudKitDatabase, from none to automatic. I have the feeling that changing the name of the configuration also changes some reference to the db itself, but if I were not to change the name, the app would have crashed because unable to migrate. What's the best approach to take here?

Hello, I’m upgrading my app from Core Data to SwiftData. Due to my old setup the Core Data store has an explicitly name like „Something.sqlite“, because it was defined via NSPersistentContainer(name: "Something") before switching to SwiftData. Now my goal is to migrate the Core Data stack to SwiftData, while moving it to an App Group (for Widget support) as well as enable iCloud sync via CloudKit. Working Migration without App Group & CloudKit I’ve managed to get my migration running without migrating it to an App Group and CloudKit support like so: @main struct MyAppName: App { let container: ModelContainer init() { // Legacy placement of the Core Data file. let dataUrl = URL.applicationSupportDirectory.appending(path: "Something.sqlite") do { // Create SwiftData container with migration and custom URL pointing to legacy Core Data file container = try ModelContainer( for: Foo.self, Bar.self, migrationPlan: MigrationPlan.self, configurations: ModelConfiguration(url: dataUrl)) } catch { fatalError("Failed to initialize model container.") } } var body: some Scene { WindowGroup { ContentView() } .modelContainer(container) } } How To Migrate to App Group & CloudKit? I’ve already tried to use the ModelConfiguration with a name, but it seems to only look for a .store file and thus doesn’t copy over the Core Data contents. let fullSchema = Schema([Foo.self, Bar.self]) let configuration = ModelConfiguration("Something", schema: fullSchema) Can someone help me how to do this migration or point me into the right direction? I can’t find anything relating this kind of migration …

I have been working on an ios application which I decided to use the new SwiftData architecture, and I now have realized that SwiftData does not support public or shared databases using SwiftData. I am a new and upcoming Swift developer, who has been self learning the Apple Swift technology. I just learned in this forum that Swift Data does not support Public and Shared Data and I also understand that no plans that have been announced to addressed this feature in the IOS 18 release time frame. The use case for my application is to implement a social type application, something like applications including X, facebook, etc. These type of applications appear to use Public, Shared and Private data in various existing Apple application. I would like to complete an application using Swift using ICloud, but I must assume that these current social applications are using other technologies. I am assuming you can do this in Core Data, but my understanding is Apple is asking that we use Swift Data to replace core data. I also am assuming that Swift data is built on core data technology layers. So ... to me it seems hopeful, somehow, to accomplish this using IOS 17 and follow the recommend Swift Data Path. What are my options for completing these data objectives in IOS? I hope I am addressing these questions in the proper and best forum? Much thanks for any suggestions.

sample code let modelConfiguration = ModelConfiguration() // 1. create mom guard let mom = NSManagedObjectModel.makeManagedObjectModel(for: [Attachment.self]) else { fatalError("====> makeManagedObjectModel error") } // 2. create description with config url and setting let description = NSPersistentStoreDescription(url: modelConfiguration.url); description.shouldAddStoreAsynchronously = false; container = NSPersistentCloudKitContainer(name: "swiftDataCloudTest", managedObjectModel: mom); container.persistentStoreDescriptions = [description] // 3. get modelContainer let modelContainer = try! ModelContainer(for: Attachment.self, configurations: self.modelConfiguration) this code works fine on MacOS(14.4.1) and previous iOS 17.x.（iOS 17.2 is OK） but on iOS 17.5, the app crashes with message A Core Data error occurred." UserInfo={NSLocalizedFailureReason=Unable to find a configuration named 'default' in the specified managed object model how can I fix these?

Target tvOS 17.4 macOS Version 14.5 Xcode Version 15.4 (15F31d) I am working on integrating SwiftData (not migrating from CoreData) into an app in active development for tvOS, and I cannot get the project to compile whenever the @Model macro is introduced. I've traced every error back to the code generated by the @Model, and commenting it out removes the errors. I am able to use @Model on a fresh project, but any attempt to import SwiftData results in the build failing with the following errors: /var/folders/t5/c9qp7_4j19x9s3p3z26kn6v80000gn/T/swift-generated-sources/@__swiftmacro_9AeolusKit11DeviceModel0D0fMe_.swift:1:1 Type 'DeviceModel' does not conform to protocol 'Observable' /var/folders/t5/c9qp7_4j19x9s3p3z26kn6v80000gn/T/swift-generated-sources/@__swiftmacro_9AeolusKit11DeviceModelC2id18_PersistedPropertyfMa_.swift:4:9 Member 'setValue' cannot be used on value of type 'any BackingData<DeviceModel>'; consider using a generic constraint instead /var/folders/t5/c9qp7_4j19x9s3p3z26kn6v80000gn/T/swift-generated-sources/@__swiftmacro_9AeolusKit11DeviceModel0D0fMe_.swift:4:36 'Observable' is not a member type of struct 'AeolusKit.Observation' /var/folders/t5/c9qp7_4j19x9s3p3z26kn6v80000gn/T/swift-generated-sources/@__swiftmacro_9AeolusKit11DeviceModelC2id18_PersistedPropertyfMa_.swift:4:50 Cannot convert value of type 'String' to expected argument type 'PersistentIdentifier' /var/folders/t5/c9qp7_4j19x9s3p3z26kn6v80000gn/T/swift-generated-sources/@__swiftmacro_9AeolusKit11DeviceModelC2id18_PersistedPropertyfMa_.swift:8:54 Cannot infer key path type from context; consider explicitly specifying a root type /var/folders/t5/c9qp7_4j19x9s3p3z26kn6v80000gn/T/swift-generated-sources/@__swiftmacro_9AeolusKit11DeviceModelC2id18_PersistedPropertyfMa_.swift:12:64 Cannot infer key path type from context; consider explicitly specifying a root type /var/folders/t5/c9qp7_4j19x9s3p3z26kn6v80000gn/T/swift-generated-sources/@__swiftmacro_9AeolusKit11DeviceModel0D0fMm_.swift:25:50 Type 'Observation' has no member 'ObservationRegistrar' the code in question causing the error: import Foundation import SwiftData @Model public final class DeviceModel { @Attribute(.unique) public var id: String init(id: String) { self.id = id } } I've already done the following: clean the project erase the contents of the derived directory restart xcode restart my mac. I want to emphasize, I do not believe it is my code causing this issue, as commenting out the @Model result's in a perfectly normal build with no warnings or errors Any help is appreciated

As I am new to programming in Swift, I have a question about SwiftData if you are writing a program and created your model and done some testing and realize you need to add something to your model that you missed during the initial setup do you have to start a whole new project? As I noticed when adding in something new to the model the project can't find the original SwiftData? Thread 1: Fatal error: failed to find a currently active container for User

I'm trying to filter results to get all characters that are associated with a story. When navigating to the view it filters as it should, but as soon as you select the Add Character option, the app just freezes. I've found that if I comment out the Query line in the init, and filter out as part of the foreach I don't get the freeze. Can anyone advise how I should be doing these predicates as it seems init isn't the best place to do it The views code is import SwiftUI import SwiftData struct CharacterListView: View { let story : Story @Query(sort: \Character.name, order: .forward) private var characters: [Character] var body: some View { List { ForEach(characters) { char in CharacterListCellView(char: char) } } .toolbar { ToolbarItem { NavigationLink(destination: CharacterAddView(story: story)) { Label("Add Character", systemImage: "plus") } } } .navigationBarTitle("Characters", displayMode: .inline) } init(story: Story) { self.story = story let id = story.persistentModelID let predicate = #Predicate<Character> { char in char.story?.persistentModelID == id } _characters = Query(filter: predicate, sort: [SortDescriptor(\.name)] ) } } I've narrowed it down to a line in the AddCharacterView file struct CharacterAddView: View { @Environment(\.modelContext) private var modelContext @Environment(\.dismiss) var dismiss let story : Story // Character details @State private var characterName: String = "" // Images @State private var showImageMenu = false; @State private var isShowPhotoLibrary = false @State private var isShowCamera = false //@State private var image = UIImage() <-- This line @State private var imageChanged = false @State private var isSaving : Bool = false var body: some View { } } If I do either of the below it works If I comment out the UIImage variable then I don't get the freeze, but I can't update the image variable If I comment out the query in init, then it works but doesn't filter and I have to do it as part of the foreach

I'm currently working on SwiftData, and having trouble with id properties. I was constantly getting this error with my @Model. error: Row (pk = 1) for entity 'AnalyzedMessage' is missing mandatory text data for property 'id' Timestamp: 2024-05-31 14:13:24.483647+09:00 | Library: CoreData | Subsystem: com.apple.coredata | Category: error \ @Model final class AnalyzedMessage { var id: String var user: User var createdAt: Date var text: String var attachments: [Attachment] var recording: Recording? var replyMessage: ReplyMessage? } As I remove all properties named id (including custom Value types), error just disappeared and app works as I intended with no issue . @Model final class AnalyzedMessage { var messageID: String var user: User var createdAt: Date var text: String var recording: Recording? } I thought using property named id causes problem only when fetching some data like this: context.model(for: myModel.id). So, is property id taken by @Model and forbidden to use? If so, I think there should be a safe-guard for miss-usage just like in my case. +) However, lots of open-source libraries use property id for their models. Do we have to handle all of these models to bypass not to use it? I think it's pretty disturbing..

I have an app that uses CoreData and I want to migrate to SwiftData. After following the Migrate to SwiftData session, I only need to point to my old Core Data file to read the old data and convert it to the new SwiftData format. My question is how do I do this? Maybe worth mentioning is that my NSPersistentContainer(name: "Model") is different to my app name. Possible Solution? According to a Tweet by Donny Wals this is done this way: By default a SwiftData ModelContainer will create its underlying storage in a file called default.store. If you want to change this so you can use an existing Core Data SQLite file, you can point your container to that file instead: // point to your old sqlite file let url = URL.applicationSupportDirectory.appending(path: "Model.sqlite") let config = ModelConfiguration(url: url) modelContainer = try ModelContainer(for: [ Movie.self ], config) My Tested Code @main struct SwiftData_TestApp: App { let url = URL.applicationSupportDirectory.appending(path: "Model.sqlite") let config = ModelConfiguration(url: url) let modelContainer = try ModelContainer(for: [ Item.self ], config) var body: some Scene { WindowGroup { ContentView() } .modelContainer(modelContainer) } } The problem here is that I don’t get it to work in the main app struct. When using this the way described in Dive deeper into SwiftData (at 6:58) I only get the error: Cannot use instance member 'url' within property initializer; property initializers run before 'self' is available PS: There seems to be an issue with this WWDC session method anyway – see this post.

I had a simple class called Entry with one field (timestamp: Date) and I tried to add a new field without having to uninstall the app , so I would not crash. I tried implementing the MigrationPlan stuff but I do not know if I have to manually add a value to the new field or how exactly it works. Here is my code. When I use the EntrySchemaV0 it works fine but if I try to use the V1 it crashes. (could not fetch ModelContainer) I also tried it with a custom migration stage. Crashes with error (SwiftData/BackingData.swift:432: Fatal error: Expected only Arrays for Relationships - String) import Foundation import SwiftData enum EntrySchemaV0: VersionedSchema { static var versionIdentifier = Schema.Version(0, 1, 0) static var models: [any PersistentModel.Type] { [Entry.self] } @Model final class Entry { var timestamp: Date init(timestamp: Date) { self.timestamp = timestamp } } } enum EntrySchemaV1: VersionedSchema { static var versionIdentifier = Schema.Version(0, 2, 0) static var models: [any PersistentModel.Type] { [Entry.self] } @Model final class Entry { var name: String var timestamp: Date init(name: String = "", timestamp: Date = .now) { self.name = name self.timestamp = timestamp } } } enum EntryMigrationPlan: SchemaMigrationPlan { static var schemas: [any VersionedSchema.Type] { [EntrySchemaV0.self, EntrySchemaV1.self] } static var stages: [MigrationStage] { [migrateV0toV1] } static let migrateV0toV1 = MigrationStage.lightweight( fromVersion: EntrySchemaV0.self, toVersion: EntrySchemaV1.self ) }

Hello, im trying to parse a JSON Request into a Swift Data Model. The specific bug happens with the nutriscore. It works perfectly fine if I do my request and Decode or Encode the Model directly. But when im trying to add it to the Database the field is empty. Somehow when im iterating through each product (my model) and console log it, it works. But only if there is one product in my database. sometimes when im adding another product, it somehow deletes(?) all nutriscores and the console log prints "nil" for all products. even for the product it worked before. This right here is the way I insert into my database which should be perfectly fine. And the printing works also perfectly fine and it always displays the correct nutriscore func dataScanner(_ dataScanner: DataScannerViewController, didAdd addedItems: [RecognizedItem], allItems: [RecognizedItem]) { for item in addedItems { if case let .barcode(barcode) = item { performAPIRequest(with: barcode.payloadStringValue!) { result in switch result { case .success(let product): ... var descriptor: FetchDescriptor<Product> { var descriptor = FetchDescriptor<Product>( predicate: #Predicate { $0.code == product.code } ) descriptor.fetchLimit = 1 return descriptor } var products: [Product] = [] products = try! self.parent.context.fetch(descriptor) print(product.nutriscore ?? "no nutri"); //WORKS PERFECTLY FINE!! if let existingProduct = products.first { existingProduct.amount! += 1 existingProduct.lastScannedAt = Date() } else { self.parent.context.insert(product) } self.processMeals() case .failure(let error): print("Error: \(error)") } } } } } This has to be a SwiftData Bug, or why doesn't it work

I modified the default Items example from xcode to include two models, a view with a query and a detail view. On this detail view I cannot properly move all items, only the top two, please see the attached video. Especially strange is that some dragging does work and some does not. It changes with the number of sub-items on a todo. The models are SwiftData and it is have a one-to-many relationship. On the many relationship the problem exists. How should the code be adjusted to make sure all items are draggable? https://imgur.com/a/n1y7iXX Below is all code necessary for the minimal example. I target iOS 17.5 and this shows on both preview, simulator and my iPhone. Models @Model final class ToDo { var timestamp: Date var items: [Item] init(timestamp: Date) { self.timestamp = timestamp self.items = [] } } @Model final class Item { var timestamp: Date var done: Bool init(timestamp: Date, done: Bool) { self.timestamp = timestamp self.done = done } } ItemListView (Here is the problem!) struct ItemListView: View { @Bindable var todo: ToDo var body: some View { List { ForEach($todo.items) { $item in Text(item.timestamp.description) } .onMove { indexSet, offset in todo.items.move(fromOffsets: indexSet, toOffset: offset) } } } } ContentView struct ContentView: View { @Environment(\.modelContext) private var modelContext @Query var items: [ToDo] var body: some View { NavigationSplitView { List { ForEach(items) { item in NavigationLink { ItemListView(todo: item) } label: { Text(item.timestamp, format: Date.FormatStyle(date: .numeric, time: .standard)) } } .onDelete(perform: deleteItems) } .toolbar { ToolbarItem(placement: .navigationBarTrailing) { EditButton() } ToolbarItem { Button(action: addItem) { Label("Add Item", systemImage: "plus") } } } } detail: { Text("Select an item") } } private func addItem() { withAnimation { let newItem = ToDo(timestamp: Date()) modelContext.insert(newItem) } } private func deleteItems(offsets: IndexSet) { withAnimation { for index in offsets { modelContext.delete(items[index]) } } } } APP @main struct ListProjectApp: App { var sharedModelContainer: ModelContainer = { let schema = Schema([ ToDo.self, ]) let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false) do { return try ModelContainer(for: schema, configurations: [modelConfiguration]) } catch { fatalError("Could not create ModelContainer: \(error)") } }() var body: some Scene { WindowGroup { ContentView() } .modelContainer(ToDoContainer.create()) } } actor ToDoContainer { @MainActor static func create() -> ModelContainer { let schema = Schema([ ToDo.self, Item.self ]) let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false) let container = try! ModelContainer(for: schema, configurations: [modelConfiguration]) let todo = ToDo(timestamp: Date()) container.mainContext.insert(todo) let item1 = Item(timestamp: Date(), done: false) let item2 = Item(timestamp: Date(), done: false) let item3 = Item(timestamp: Date(), done: false) todo.items.append(item1) todo.items.append(item2) todo.items.append(item3) return container } }

In my application, I query with @ModelActor. My goal in doing this is to perform the query operation in the background thread. I use .task(priority:) to display the queries. I want to use withAnimation inside the task, but as you know, it cannot be used with asynchronous functions. I'm waiting for your comments and ideas on how to do it. Thank you.

The context is to create a model instance in SwitfData and return it. This model as a unique attribute (defined by @Attribute(.unique)). The application runs fine the first time but on the second run, it fails with EXC_BAD_INSTRUCTION (code=EXC_I386_INVOP). What the reason behind this crash? Here is my sample application to duplicate the issue. The issue is reproducible on MacOS and iOS: import SwiftUI import SwiftData @available(iOS 17, *) @available(macOS 11, *) @Model public final class MyModel : CustomStringConvertible { @Attribute(.unique) var uuid: UUID init(uuid: UUID) throws { self.uuid = uuid } public var description: String { return self.uuid.uuidString } } @available(iOS 17, *) @available(macOS 11, *) @ModelActor public actor LocalDatabaseService { public static let shared = LocalDatabaseService() let schema = Schema([MyModel.self]) public init() { self.modelContainer = try! ModelContainer(for: self.schema) let context = ModelContext(modelContainer) self.modelExecutor = DefaultSerialModelExecutor(modelContext: context) } public func createMyModel(uuid: UUID) throws -> MyModel { let myModel = try MyModel(uuid: uuid) let modelContext = self.modelContext modelContext.insert(myModel) try modelContext.save() return myModel } } struct ContentView: View { var body: some View { Task { let id = UUID(uuidString: "9C66CA5B-D91C-480F-B02C-2D14EEB49902")! let myModel = try await LocalDatabaseService.shared.createMyModel(uuid: id) print("myModel:\(myModel)") print("DONE") } return VStack { Image(systemName: "globe") .imageScale(.large) .foregroundStyle(.tint) Text("Hello, world!") } .padding() } } #Preview { return ContentView() } Note: a workaround is to returned the fetched model instance return try self.getMyModel(uuid: uuid): func getMyModel(uuid: UUID) throws -> MyModel { let fetchDescriptor = FetchDescriptor<MyModel>(predicate: #Predicate { $0.uuid == uuid }) let serverList = try modelContext.fetch(fetchDescriptor) if !serverList.isEmpty { if let first = serverList.first { return first } } fatalError("Could not find MyModel with uuid \(uuid)") } ... but it does not explain the crash.

For a kind of podcast player I need to periodically update a swiftData object to keep track of the listening progress. (Happy to hear if there are better ways) I need to do this in many places in my app so I wanted to extract the modelContext into a Singleton so I can write a global function that starts the timer. In doing so I stumbled upon a problem: The memory used by my app is steadily increasing and the device is turning hot. @Observable class Helper { static let shared = Helper() var modelContext: ModelContext? } @main struct SingletontestApp: App { let modelContainer: ModelContainer init() { do { modelContainer = try ModelContainer( for: Item.self, Item.self ) } catch { fatalError("Could not initialize ModelContainer") } Helper.shared.modelContext = modelContainer.mainContext } var body: some Scene { WindowGroup { ContentView() } .modelContainer(modelContainer) } } struct ContentView: View { @Query private var items: [Item] var body: some View { NavigationSplitView { List { ForEach(items) { item in Text(item.timestamp, format: Date.FormatStyle(date: .numeric, time: .standard)) } } .toolbar { ToolbarItem { Button(action: addItem) { Label("Add Item", systemImage: "plus") } } ToolbarItem { Button(action: updateItemPeriodically) { Label("Change random", systemImage: "dice") } } } } detail: { Text("Select an item") } } func addItem() { withAnimation { let newItem = Item(timestamp: Date()) Helper.shared.modelContext!.insert(newItem) } } @MainActor func updateItemPeriodically() { // Doesn't matter if run as global or local func let descriptor = FetchDescriptor<Item>(sortBy: [SortDescriptor(\.timestamp)]) let results = (try? Helper.shared.modelContext?.fetch(descriptor)) ?? [] let element = results.randomElement() let timer = Timer.scheduledTimer(withTimeInterval: 2, repeats: true) { timer in // Smaller time intervals worsen the problem element?.timestamp = Date.now } } } Calling save() manually or automatically in the timer does not have any effect. I am not sure about my general way of keeping track of listening process so if you think there is a better way, feel free to correct me. Thanks for your help

Hi, I'm about to adopt .externalStorage but I will also use CloudKit in the near future. I did not find any reference that list of requirements for SwiftData models to be used with CloudKit, only for Core Data models. It seems those Core Data requirements (like no-unique) apply to SwiftData as well. However I did not find any info on this: Can @Attribute(.externalStorage) be used when I want to sync my model with CloudKit?

Here is my current code: @Model final public class ServerModel { @Attribute(.unique) var serverUrl: URL init(serverUrl: URL) { self.serverUrl = serverUrl } } @ModelActor public actor MyDatabaseService { public static var shared = MyDatabaseService() public init() { self.modelContainer = try! ModelContainer(for: ServerModel.self) let context = ModelContext(modelContainer) self.modelExecutor = DefaultSerialModelExecutor(modelContext: context) } public func listServers() throws -> [ServerModel] { let descriptor = FetchDescriptor<ServerModel>() return try modelContext.fetch(descriptor) } } When try to call try await MyDatabaseService.shared.listServers() There are two problems: ServerModel is not Sendable "Reference to static property 'shared' is not concurrency-safe because it involves shared mutable state; this is an error in Swift 6" For the first one, I can solve it by doing: public struct Server { let serverUrl: URL; } @Model final public class ServerModel { @Attribute(.unique) var serverUrl: URL init(serverUrl: URL) { self.serverUrl = serverUrl } func getSendable() -> Server { return Server(serverUrl: self.serverUrl) } } @ModelActor public actor MyDatabaseService { (...) public func listServers() throws -> [Server] { let descriptor = FetchDescriptor<ServerModel>() return try modelContext.fetch(descriptor).map { $0.getSendable() } } } I am wondering if there is a smarter solution to this first issue. SwiftData already require to define the model with basic/codable types, so if there was a magic way to get a sendable from the model. I try to make my model 'Codable' but 'Codable' is not compatible with 'Sendable'. For my second issue, the singleton issue. I do not really know how to fix it.