Hello, I want to build an app that will allow the user to entry some health related records and be synced with the HealthKit. Any record that is in the HealthKit is stored locally on the device. I find it conceptually unsure if I should be storing the HealthKit records in the SwiftData to make the user records available across the iCloud synced devices. Should I read the HealthKit record, make a copy of it (including it's ID) on my app's data in SwiftData? How the syncing should be done the right way? thanks.

If I annotate a class with @Observable I get this error in @Query: Expansion of macro 'Query()' produced an unexpected 'init' accessor If I remove @Observable the error goes away. Elsewhere I have .environment referencing the class. With @Observable this complains that the class needs to be @Observable. I am mystified. Does anyone have a suggestion?

I've been going through SwiftData documentation, as I'm trying to learn how to work with SwiftData, especially how to use it to cache web responses. "Maintaining a local copy of server data" sample seems to be perfect source for me then, but I find it a little bit confusing, or lacking. There's this function: /// Loads new earthquakes and deletes outdated ones. @MainActor static func refresh(modelContext: ModelContext) async { do { // Fetch the latest set of quakes from the server. logger.debug("Refreshing the data store...") let featureCollection = try await fetchFeatures() logger.debug("Loaded feature collection:\n\(featureCollection)") // Add the content to the data store. for feature in featureCollection.features { let quake = Quake(from: feature) // Ignore anything with a magnitude of zero or less. if quake.magnitude > 0 { logger.debug("Inserting \(quake)") modelContext.insert(quake) } } logger.debug("Refresh complete.") } catch let error { logger.error("\(error.localizedDescription)") } } It says specifically that it "deletes outdated ones", but where does the actual deletion happens? All I can see is call to modelContext.insert(quake) which will update existing entries or create new ones if they don't exist yet, if I'm understanding things right. But quakes that were already in the database, and are not present in the response, don't seem to be deleted anywhere in this function. Or am I missing something?

I have a view which is a form allowing me to edit details of a category item. In the toolbar, there is a button called "Cancel," whose sole function is to call the rollback function in the ModelContext class. This function should allow you to revert any changes made to the context. However, it appears that this rollback function is neither triggering the view update nor working properly, as I need to restart the app to see the changes reverted which just work when the property "isAutosaveEnabled" is set to false. Container configuration goes below import SwiftUI @main struct Index: App { var body: some Scene { WindowGroup { Window() } .modelContainer( for: [ Bill.self, Category.self ], isAutosaveEnabled: false, isUndoEnabled: true ) } } Rollback usage that don't work import SwiftUI import SwiftData import Foundation struct CategoryForm: View { @Environment(\.presentationMode) private var presentationMode @Environment(\.modelContext) private var modelContext @Bindable var category: Category var body: some View { NavigationStack { Form { Section( header: Text("Basic Information"), content: { TextField("Title", text: $category.name) } ) } .navigationTitle("New Category") .navigationBarTitleDisplayMode(.inline) .toolbar { // Cancel Button ToolbarItem( placement: .topBarLeading, content: { Button( action: onCancel, label: { Text("Cancel") } ) } ) // Done Button ToolbarItem( placement: .topBarTrailing, content: { Button( action: onDone, label: { Text("Done") } ) .disabled(category.name.isEmpty) } ) } } } func onCancel() { modelContext.rollback() presentationMode.wrappedValue.dismiss() } func onDone() { modelContext.insert(category) do { try modelContext.save() } catch { fatalError("Failed to save category") } presentationMode.wrappedValue.dismiss() } }

iPad mini device with iPadOS 17.4.1. I get this failure on iPad mini device exclusively. I have universal app and I doesn't get this error neither on iPhone or any simulator or macOS. I tried to reset the iPad, still getting the error. The error happens when I send the app to background from the particular app screen. Here is the error: error: Store failed to load. <NSPersistentStoreDescription: 0x3004b4bd0> (type: SQLite, url: file:///dev/null) with error = Error Domain=NSCocoaErrorDomain Code=134060 "A Core Data error occurred." UserInfo={NSLocalizedFailureReason=The configuration named 'default' does not contain any entities.} with userInfo { NSLocalizedFailureReason = "The configuration named 'default' does not contain any entities."; } What error says is that it loaded the store from file:///dev/null, which is wrong. Basically it looses the model container which is added via modelContaner modificator to the root view. The error get caused particularly by the @Environment(\.modelContext) private var modelContext call in the view on which the failure occurs. This view is deep in the view hierarchy, and it get's created in the navigationDestination block. I fixed the error by supplying modelContainer one more time right on the view: .navigationDestination(for: File.self) { file in FileEditor(file: file) .modelContainer(FolderService.modelContainer) } I wonder, why can it loose the model container which is supplied on the root view?

Recently, I have been using SwiftData as a data persistence tool in my new SwiftUI app. My app utilizes CLLocationManager for background location tracking to wake up the app and update SwiftData-related data. When the app is in the foreground or background, SwiftData's @Query can normally retrieve data. However, once the user manually terminates the app and it receives a location-based wake-up, SwiftData's @Query no longer retrieves data. I have looked through many resources and haven't found any similar documentation. I wonder if anyone can give me some suggestions?

I have v3 models in coredata (model: Event, Lecture), and make new model in v4 with swiftdata but model name, property is different (model: EventModel, LectureModel). For migration, I add V3Schema, V4Schema and MigrationPlan. enum V4Schema: VersionedSchema { static var models: [any PersistentModel.Type] = [LectureModel.self, EventModel.self ] static var versionIdentifier = Schema.Version(4, 0, 0) } enum V3Schema: VersionedSchema { static var models: [any PersistentModel.Type] = [Event.self, Lecture.self] static var versionIdentifier = Schema.Version(3, 5, 2) } enum ModelMigrationPlan: SchemaMigrationPlan { static var schemas: [any VersionedSchema.Type] = [V3Schema.self, V4Schema.self] static var stages: [MigrationStage] = [migrateV3ToV4] } extension ModelMigrationPlan { static let migrateV3ToV4 = MigrationStage.custom(fromVersion: V3Schema.self, toVersion: V4Schema.self, willMigrate: willMigrate, didMigrate: { _ in Log.debug(message: "Migration Complete") }) } private func willMigrate(context: ModelContext) throws { try migrateLectures(context: context) try migrateEvents(context: context) try context.save() } private func migrateEventTypes(context: ModelContext) throws { // create new v4 event model using v3 event model. } private func migrateLectures(context: ModelContext) throws { // create new v4 lecture model using v3 lecture model. } static let release: ModelContainer = { let v4Schema = Schema(V4Schema.models) let containerURL = FileManager.default.containerURL(forSecurityApplicationGroupIdentifier: "app group id") let databaseURL = containerURL?.appending(path: "**.sqlite") let configuration = ModelConfiguration("**", schema: v4Schema, url: databaseURL!, cloudKitDatabase: .private("**")) #if DEBUG do { try autoreleasepool { let desc = NSPersistentStoreDescription(url: configuration.url) let opts = NSPersistentCloudKitContainerOptions(containerIdentifier: configuration.cloudKitContainerIdentifier!) desc.cloudKitContainerOptions = opts desc.shouldAddStoreAsynchronously = false if let model = NSManagedObjectModel.makeManagedObjectModel(for: V4Schema.models) { let container = NSPersistentCloudKitContainer(name: "**", managedObjectModel: model) container.persistentStoreDescriptions = [desc] container.loadPersistentStores(completionHandler: { _, err in if let err { Log.error(message: "Store open failed: \(err.localizedDescription)") } }) try container.initializeCloudKitSchema() Log.debug(message: "Initialize Cloudkit Schema") if let store = container.persistentStoreCoordinator.persistentStores.first { try container.persistentStoreCoordinator.remove(store) } } } } catch { Log.error(message: "Failed: \(error.localizedDescription)") } #endif return try! ModelContainer(for: v4Schema, migrationPlan: ModelMigrationPlan.self, configurations: configuration) }() But when I run, I got error message. CoreData: CloudKit: CoreData+CloudKit: -[NSCloudKitMirroringDelegate _scheduleAutomatedExportWithLabel:activity:completionHandler:]_block_invoke(3508): <NSCloudKitMirroringDelegate: 0x1036b1540> - Finished automatic export - ExportActivity - with result: <NSCloudKitMirroringResult: 0x1035da810> storeIdentifier: ***** success: 0 madeChanges: 0 error: Error Domain=NSCocoaErrorDomain Code=134407 "Request '*****' was cancelled because the store was removed from the coordinator." UserInfo={NSLocalizedFailureReason=Request '****' was cancelled because the store was removed from the coordinator.} I don't know why store was removed from the coordinator. Any have solutions?

I have a situation where tapping on a NavigationLink on an item from a SwiftData Query results in an infinite loop, causing the app the freeze. If you run the code, make sure to add at least 1 item, then tap on it to see the issue. Here is the code for a small sample app I made to illustrate the issue: import SwiftUI import SwiftData @main struct TestApp: App { var sharedModelContainer: ModelContainer = { let schema = Schema([ Item.self ]) let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false) do { let container = try ModelContainer(for: schema, configurations: [modelConfiguration]) return container } catch { fatalError("Could not create ModelContainer: \(error)") } }() var body: some Scene { WindowGroup { ContentView() } .modelContainer(sharedModelContainer) } } struct ContentView: View { var body: some View { NavigationStack { ListsView() } } } struct ListsView: View { @Environment(\.modelContext) private var modelContext @Query(filter: #Predicate<Item> { _ in true }) private var items: [Item] var body: some View { List(items) { item in NavigationLink { ItemDetail() } label: { VStack { Text("\(item.name) | \(item.date.formatted())") } } } Button("Add") { let newItem = Item(name: "Some item", date: .now) modelContext.insert(newItem) try? modelContext.save() } } } struct ItemDetail: View { private var model = ItemModel() var body: some View { VStack { Text("detail") } } } fileprivate var count = 0 class ItemModel { var value: Int init() { value = 99 print("\(count)") count += 1 } } @Model final class Item { let name: String let date: Date init(name: String, date: Date) { self.name = name self.date = date } } In the test app above, the code in the initializer of ItemModel will run indefinitely. There are a few things that will fix this issue: comment out the private var model = ItemModel() line in ItemDetail view replace the @Query with a set list of Items move the contents of the ListsView into the ContentView instead of referencing ListsView() inside the NavigationStack But I'm not sure why this infinite loop is happening with the initializer of ItemModel. It seems like a SwiftData and/or SwiftUI bug, because I don't see a reason why this would happen. Any ideas? Has anyone run into something similar?

I know if i change existing properties in a @Model it’s a migration. However if I add a new @Model class(es) that has no relationships to any existing is that still a migration or am i free to add? if free to add, should i create a new model container or can I just add the new Model classes ?

I am new to Swift, and I am trying to get a grip on SwiftData, which SO FAR seems pretty straightforward EXCEPT relationships between tables. I come from a MYSQL, SQLITE3 background and I am used to “Primary Keys”, Inner and Outer Joins, One-to-One and One-to-Many relationships. Which SwiftData does not appear to do (I think). I am following several reasonably good online tutorials on the subject, all of which gloss over how relationships work. The best one is a table for vegetables alongside a table of notes for each vegetable (A one-to-many relationship). The classes we set up for the schemas are as follows. import Foundation import SwiftData @Model class Vegetable { var name: String @Relationship(deleteRule: .cascade) var notes: [Note]? init(name: String) { self.name = name } } @Model class Note { var text: String var vegetable: Vegetable? init(text: String) { self.text = text } } I can’t comprehend how they work. None of the tutorials I have watched explain it or explain it in a way I can understand. In the “Vegetable” class, why is the field “notes” an array of type Notes? Again in the “Vegetable” class does the field “notes” get stored in the database, if so what is stored? In the “Note” Class it looks like the whole of the class “Vegetable” gets stored in the variable “vegetable”, which may or may not get stored in the database.

I've run into a problem related to navigation links in child Views containing a SwiftData @Query and a predicate. When tapping on a NavigationLinks, the containing View is invalidated pausing the UI. When tapping back, the View is invalidated a second time during which time the View ignores any new taps for navigation leading to a poor user experience. A complete example: import SwiftUI import SwiftData @Model final class Item { var num: Int init(num: Int) { self.num = num } } @main struct TestSwiftDataApp: App { var sharedModelContainer: ModelContainer = { let schema = Schema([Item.self]) let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: true) let container: ModelContainer do { container = try ModelContainer(for: schema, configurations: [modelConfiguration]) } catch { fatalError("Could not create ModelContainer: \(error)") } // Add some sample data Task { @MainActor in for i in 0...1000 { container.mainContext.insert(Item(num: i)) } } return container }() var body: some Scene { WindowGroup { ContentView() } .modelContainer(sharedModelContainer) } } extension Color { static func random() -> Color { Color(red: .random(in: 0...1), green: .random(in: 0...1), blue: .random(in: 0...1)) } } struct ContentView: View { var body: some View { NavigationStack { SubView() .navigationDestination(for: Item.self) { item in Text("Item at \(item.num)") } } } } struct SubView: View { @Environment(\.modelContext) private var modelContext @Query(filter: #Predicate<Item> { item in item.num < 20 }, sort: \.num) private var items: [Item] var body: some View { let _ = Self._printChanges() List { ForEach(items) { item in NavigationLink(value: item) { Text("Item \(item.num)") }.background(Color.random()) } } } } The background colors of cells will shift every invalidation. In addition there's some debugging in there to show what's happening. When running it, I get SubView: @self, @identity, _modelContext, @128, @144 changed. SubView: @self changed. SubView: @dependencies changed. Then I tap on an item and it invalidates: SubView: @self changed. Tapping back invalidates it again during which time the UI ignores new taps: SubView: @self changed. The odd thing is, this behavior doesn't happen if the NavigationStack is moved to the child View with the NavigationLinks like this: struct ContentView2: View { var body: some View { SubView2() } } struct SubView2: View { @Environment(\.modelContext) private var modelContext @Query(filter: #Predicate<Item> { item in item.num < 20 }, sort: \.num) private var items: [Item] var body: some View { let _ = Self._printChanges() NavigationStack { List { ForEach(items) { item in NavigationLink(value: item) { Text("Item \(item.num)") }.background(Color.random()) } } .navigationDestination(for: Item.self) { item in Text("Item at \(item.num)") } } } } When running this, there's one less change as well and no invalidations on tap or back: SubView: @self, @identity, _modelContext, @128, @144 changed. SubView: @dependencies changed. The problem also doesn't happen if the @Query does not have a filter #Predicate. Unfortunately, the application in question has a deeper hierarchy where views with a @Query with a predicate can navigation to other views with a @Query and predicate, so neither solution seems ideal. Is there some other way to stop the invalidations from happening?

SwiftData includes support for CloudKit sync. However, I don't see any way to add conflict resolution behavior. For example, if different devices set different values for a field, or if a relationship is orphaned because of a deletion on another device, the application has to handle this somehow. In Core Data (which SwiftData wraps), you can handle this with the conflict resolution system (docs) and classes like NSMergePolicy. Is any of this accessible in SwiftData? If not, how do you deal with conflicts when syncing a SwiftData model with the cloud?

Hi! Not sure if this is a swift data or more a Decimal in general type of question. What's going on: I have a SwiftUI app using SwiftData, I have persisted a Model with a property "reducedPrice" of type Decimal. It's stores correctly the value. Now, I have read the value during automated tests and tried comparing the values: let reducedPrice = model.reducedPrice // swift data property let target = Decimal(4.98) // expected target value to compare to swift data value. Now if I just print the result of the comparison between those 2 I get a false result. print(reducedPrice == target) //output : false The swift data model was populated from a direct copy of another struct that comes from an JSON import using Codable+CodingKeys (I used Decimal type). What I expected: I expected it to be true. Debug Observations I did noticed that on the variable inspector both had the same magnitudes but in reality the mantissa are different. I'm attaching a screenshot. My Theory They are different just because something under SwiftData stores different way the decimal as in comparison on how I am creating the Decimal for the comparison inside the automated tests. My question Is this expected behavior? Any suggestion on best practices on how to handle this? Thank you in advance any relevant guidance is very appreciated!

I'm developing an app with a chart in SwiftUI. I want the following block of code to run when the chart is clicked. On my personal iPhone, the app works flawlessly. But when I try it in the simulator it crashes and gives me about 5-10 of the following errors. When I remove the @Query macro from the code block, the application does not crash in the simulator, but I continue to get the errors I mentioned. If I do not run the following code block, I do not get the errors I mentioned. struct SaleDetailView: View { @Query(filter: #Predicate<Registration> { !$0.activeRegistration }) private var regs: [Registration] var body: some View { VStack { DailySaleView() } .padding() } } Thank you in advance for your answers. Do not hesitate to ask if you have any questions. Thanks, MFS

Dear all, I have the following two classes: Stagioni: import SwiftData @Model class Stagione { @Attribute(.unique) var idStagione: String var categoriaStagione: String var miaSquadra: String @Relationship(deleteRule: .cascade) var rosa: [Rosa]? @Relationship(deleteRule: .cascade) var squadra: [Squadre]? @Relationship(deleteRule: .cascade) var partita: [CalendarioPartite]? init(idStagione: String, categoriaStagione: String, miaSquadra: String) { self.idStagione = idStagione self.categoriaStagione = categoriaStagione self.miaSquadra = miaSquadra } } CalendarioPartite: import SwiftData @Model class CalendarioPartite { var idGiornata: Int var dataPartita: Date var squadraCasa: String var squadraTrasferta: String var golCasa: Int var golTrasferta: Int var stagione: Stagione? init(idGiornata: Int, dataPartita: Date, squadraCasa: String, squadraTrasferta: String, golCasa: Int, golTrasferta: Int) { self.idGiornata = idGiornata self.dataPartita = dataPartita self.squadraCasa = squadraCasa self.squadraTrasferta = squadraTrasferta self.golCasa = golCasa self.golTrasferta = golTrasferta } } Now, I'd like to have a query which is showing in a view the list of partite depending on a selection of a specific Stagione. I've tried with the following query, but I'm getting the following error: "Instance member 'selectedStagione' cannot be used on type 'CalendarioCampionatoView'; did you mean to use a value of this type instead?" @Query(filter: #Predicate<CalendarioPartite> { $0.stagione == selectedStagione}) private var partite: [CalendarioPartite] = [] What I'm doing wrong? Thanks, A.

Can anyone give me assistance on how to fix this. My preview crashed because a Fatal Error in ModelData. This is how my ModelData looks: import SwiftUI struct SutraokeDetail: View { @Environment(ModelData.self) var modelData var sutra: Sutras var body: some View { @Bindable var modelData = modelData ScrollView { CircleImage(image: sutra.image) .offset(y: -130) .padding(.bottom, -130) VStack(alignment: .leading) { HStack{ Text(sutra.name) .font(.title) Spacer() Text(sutra.text) } } } } } #Preview { let modelData = ModelData() return SutraokeDetail(sutra: modelData.sutras[0]) .environment(modelData) }

UPDATED: I determined the line causing the hang was .animation(.default, value: layout). I'm seeing a strange issue when switching between a ScrollView/LazyVGrid and a List with my SwiftData but when toggling the layout it ends up freezing and I can't confirm what's causing the app to hang since there's no crash. I'm not getting much info from the debugger. Any help would be appreciated. struct ContentView: View { @Environment(\.modelContext) private var modelContext @Query private var items: [Item] let gridItemLayout = [ GridItem(.adaptive(minimum: 150))] @State private var layout = Layout.grid var body: some View { NavigationStack { ZStack { if layout == .grid { ScrollView { LazyVGrid(columns: gridItemLayout, spacing: 5) { ForEach(items) { item in } } } } else { List { ForEach(items) { item in } } } } // MARK: HERE'S THE ERROR .animation(.default, value: layout) .navigationTitle("ScrollView") .toolbar { ToolbarItemGroup { Button(action: addItem) { Label("Add Item", systemImage: "plus") } Menu { Picker("Layout", selection: $layout) { ForEach(Layout.allCases) { option in Label(option.title, systemImage: option.imageName) .tag(option) } } .pickerStyle(.inline) } label: { Label("Layout Options", systemImage: layout.imageName) .labelStyle(.iconOnly) } } } } } } @Model public class Item: Codable { public let id: String public enum CodingKeys: String, CodingKey { case id } public init(id: String) { self.id = id } required public init(from decoder: Decoder) throws { let container = try decoder.container(keyedBy: CodingKeys.self) id = try container.decode(String.self, forKey: .id) } public func encode(to encoder: Encoder) throws { var container = encoder.container(keyedBy: CodingKeys.self) try container.encode(id, forKey: .id) } }

Has anyone successfully persisted Color, particularly in SwiftData? So far my attempts have failed: Making Color conform to Codable results in a run time error (from memory something about ColorBox). Color.Resolved already conforms Codable but this results in "SwiftData/ModelCoders.swift:124: Fatal error: Composite Coder only supports Keyed Container" None of the other color types conform to Codable (CGColor, NSColor and UIColor) so does the swift language really not have a persistable color type?

Hello everyone, I looked at various methods how to Unit/UITest SwiftData but I couldn't find something simple. Is it even possible to test SwiftData? Does someone found a solution for that?

I have an Apple app that uses SwiftData and icloud to sync the App's data across users' devices. Everything is working well. However, I am facing the following issue: SwiftData does not support public sharing of the object graph with other users via iCloud. How can I overcome this limitation without stopping using SwiftData? Thanks in advance!