Someone smarter than me please tell me if this will work... I want to have an edit screen for a SwiftData class. Auto Save is on, but I want to be able to revert changes. I have read all about sending a copy in, sending an ID and creating a new context without autosave, etc. What about simply creating a second set of ephemeral values in the actual original model. initialize them with the actual fields. Edit them and if you save changes, migrate that back to the permanent fields before returning. Don't have to manage a list of @State variables corresponding to every model field, and don't have to worry about a second model context. Anyone have any idea of the memory / performance implications of doing it this way, and if it is even possible? Does this just make a not quite simple situation even more complicated? Haven't tried yet, just got inspiration from reading some medium content on attributes on my lunch break, and wondering if I am just silly for considering it.

I built a SwiftData App that relies on CloudKit to synchronize data across devices. That means all model relationships must be expressed as Optional. That’s fine, but there is a limitation in using Optional’s in SwiftData SortDescriptors (Crashes App) That means I can’t apply a SortDescriptor to ModelA using some property value in ModelB (even if ModelB must exist) I tried using a computed property in ModelA that referred to the property in ModelB, BUT THIS DOESN”T WORK EITHER! Am I stuck storing redundant data In ModelA just to sort ModelA as I would like???

Hi, I'm getting a very odd error log in my SwiftData setup for an iOS app. It is implemented to support schema migration. When starting the app, it simply prints the following log twice (seems to be dependent on how many migration steps, I have two steps in my sample code): CoreData: error: Attempting to retrieve an NSManagedObjectModel version checksum while the model is still editable. This may result in an unstable verison checksum. Add model to NSPersistentStoreCoordinator and try again. (Yes there is a mistyped word "verison", this is exactly the log) The code actually fully works. But I have neither CloudKit configured, nor is this app in Production yet. I'm still just developing. Here is the setup and code to reproduce the issue. Development mac version: macOS 15.5 XCode version: 16.4 iOS Simulator version: 18.5 Real iPhone version: 18.5 Project name: SwiftDataDebugApp SwiftDataDebugApp.swift: import SwiftUI import SwiftData @main struct SwiftDataDebugApp: App { var sharedModelContainer: ModelContainer = { let schema = Schema([ Item.self, ]) let modelConfiguration = ModelConfiguration(schema: schema, isStoredInMemoryOnly: false, allowsSave: true) do { return try ModelContainer(for: schema, migrationPlan: ModelMigraitonPlan.self, configurations: [modelConfiguration]) } catch { fatalError("Could not create ModelContainer: \(error)") } }() var body: some Scene { WindowGroup { ContentView() } .modelContainer(sharedModelContainer) } } Item.swift: import Foundation import SwiftData typealias Item = ModelSchemaV2_0_0.Item enum ModelSchemaV1_0_0: VersionedSchema { static var versionIdentifier = Schema.Version(1, 0, 0) static var models: [any PersistentModel.Type] { [Item.self] } @Model final class Item { var timestamp: Date init(timestamp: Date) { self.timestamp = timestamp } } } enum ModelSchemaV2_0_0: VersionedSchema { static var versionIdentifier = Schema.Version(2, 0, 0) static var models: [any PersistentModel.Type] { [Item.self] } @Model final class Item { var timestamp: Date var tags: [Tag] = [] init(timestamp: Date, tags: [Tag]) { self.timestamp = timestamp self.tags = tags } } } enum ModelMigraitonPlan: SchemaMigrationPlan { static var schemas: [any VersionedSchema.Type] { [ModelSchemaV1_0_0.self] } static var stages: [MigrationStage] { [migrationV1_0_0toV2_0_0] } static let migrationV1_0_0toV2_0_0 = MigrationStage.custom( fromVersion: ModelSchemaV1_0_0.self, toVersion: ModelSchemaV2_0_0.self, willMigrate: nil, didMigrate: { context in let items = try context.fetch(FetchDescriptor<ModelSchemaV2_0_0.Item>()) for item in items { item.tags = Array(repeating: "abc", count: Int.random(in: 0...3)).map({ Tag(value: $0) }) } try context.save() } ) } Tag.swift: import Foundation struct Tag: Codable, Hashable, Comparable { var value: String init(value: String) { self.value = value } static func < (lhs: Tag, rhs: Tag) -> Bool { return lhs.value < rhs.value } static func == (lhs: Tag, rhs: Tag) -> Bool { return lhs.value == rhs.value } func hash(into hasher: inout Hasher) { hasher.combine(value) } } ContentView.swift: import SwiftUI import SwiftData struct ContentView: View { @Environment(\.modelContext) private var modelContext @Query private var items: [Item] var body: some View { VStack { List { ForEach(items) { item in VStack(alignment: .leading) { Text(item.timestamp, format: Date.FormatStyle(date: .numeric, time: .standard)) HStack { ForEach(item.tags, id: \.hashValue) { tag in Text("\(tag.value)") } } } } .onDelete(perform: deleteItems) } Button("Add") { addItem() } .padding(.top) } } private func addItem() { withAnimation { let newItem = Item(timestamp: Date(), tags: [Tag(value: "Hi")]) modelContext.insert(newItem) } do { try modelContext.save() } catch { print("Error saving add: \(error.localizedDescription)") } } private func deleteItems(offsets: IndexSet) { withAnimation { for index in offsets { modelContext.delete(items[index]) } } do { try modelContext.save() } catch { print("Error saving delete: \(error.localizedDescription)") } } } #Preview { ContentView() .modelContainer(for: Item.self, inMemory: true) } I hope someone can help, couldn't find anything related to this log at all.

I am trying to extend my PersistedModels like so: @Versioned(3) @Model class MyType { var name: String init() { name = "hello" } } but it seems that SwiftData's@Model macro is unable to read the properties added by my @Versioned macro. I have tried changing the order and it ignores them regardless. version is not added to schemaMetadata and version needs to be persisted. I was planning on using this approach to add multiple capabilities to my model types. Is this possible to do with macros? VersionedMacro /// A macro that automatically implements VersionedModel protocol public struct VersionedMacro: MemberMacro, ExtensionMacro { // Member macro to add the stored property directly to the type public static func expansion( of node: AttributeSyntax, providingMembersOf declaration: some DeclGroupSyntax, in context: some MacroExpansionContext ) throws -> [DeclSyntax] { guard let argumentList = node.arguments?.as(LabeledExprListSyntax.self), let firstArgument = argumentList.first?.expression else { throw MacroExpansionErrorMessage("@Versioned requires a version number, e.g. @Versioned(3)") } let versionValue = firstArgument.description.trimmingCharacters(in: .whitespaces) // Add the stored property with the version value return [ "public private(set) var version: Int = \(raw: versionValue)" ] } // Extension macro to add static property public static func expansion( of node: SwiftSyntax.AttributeSyntax, attachedTo declaration: some SwiftSyntax.DeclGroupSyntax, providingExtensionsOf type: some SwiftSyntax.TypeSyntaxProtocol, conformingTo protocols: [SwiftSyntax.TypeSyntax], in context: some SwiftSyntaxMacros.MacroExpansionContext ) throws -> [SwiftSyntax.ExtensionDeclSyntax] { guard let argumentList = node.arguments?.as(LabeledExprListSyntax.self), let firstArgument = argumentList.first?.expression else { throw MacroExpansionErrorMessage("@Versioned requires a version number, e.g. @Versioned(3)") } let versionValue = firstArgument.description.trimmingCharacters(in: .whitespaces) // We need to explicitly add the conformance in the extension let ext = try ExtensionDeclSyntax("extension \(type): VersionedModel {}") .with(\.memberBlock.members, MemberBlockItemListSyntax { MemberBlockItemSyntax(decl: DeclSyntax( "public static var version: Int { \(raw: versionValue) }" )) }) return [ext] } } VersionedModel public protocol VersionedModel: PersistentModel { /// The version of this particular instance var version: Int { get } /// The type's current version static var version: Int { get } } Macro Expansion:

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.

Hi, I am experiencing main thread freezes from fetching on Main Actor. Attempting to move the function to a background thread, but whenever I reference the TestModel in a nonisolated context or in another model actor, I get this warning: Main actor-isolated conformance of 'TestModel' to 'PersistentModel' cannot be used in actor-isolated context; this is an error in the Swift 6 language mode Is there a way to do this correctly? Recreation, warning on line 13: class TestModel { var property: Bool = true init() {} } struct SendableTestModel: Sendable { let property: Bool } @ModelActor actor BackgroundActor { func fetch() throws -> [SendableTestModel] { try modelContext.fetch(FetchDescriptor<TestModel>()).map { SendableTestModel(property: $0.property) } } }

Hi, I'm considering using the new SwiftData class inheritance for a new app I'm building. I have a few questions: Is it working well enough for production? I have a number of different object types in my app. Some of them are very similar, and there's always a balance to be struck when it comes to splitting them into different types using class inheritance. Are there some good advice on when to use multiple classes instead of squeezing my object types into a single class? Is there advice against using class inheritance in multiple levels (3-4)? Claes

Hi, I’m using SwiftData with an @Observable DatabaseManager class that is shared between my app and a widget. This class is located inside a Swift package and looks roughly like this: public final class DatabaseManager { public static let shared = DatabaseManager() private init() { let groupID = "group.com.yourcompany.myApp" let config = ModelConfiguration(groupContainer: .identifier(groupID)) let c = try! ModelContainer(for: MyModel.self, configurations: config) self.container = c self.modelContext = c.mainContext } public private(set) var container: ModelContainer public private(set) var modelContext: ModelContext } In the main app, I inject the container and context like this: struct MyApp: App { var body: some Scene { WindowGroup { ContentView() .modelContainer(DatabaseManager.shared.container) .modelContext(DatabaseManager.shared.modelContext) } } } Both the widget and the main app import the same package, and both use DatabaseManager.shared for reading and writing objects. The problem: When the widget updates an object using an AppIntent, the change is not reflected in the main app unless I fully terminate and relaunch it. If I just bring the app back to the foreground, it still shows stale data. Is there a recommended way to make the main app observe or reload SwiftData changes that were made in the widget (via the same shared app group and container)? I’m already using .modelContainer(...) and .modelContext(...) in the app, and everything else works fine — it’s just the syncing that doesn’t happen unless I force-relaunch the app. Thanks!

Hi, I keep trying to use transformable to store an array of strings with SwiftData, and I can see that it is activating the transformer, but it keeps saying that I am still using NSArray instead of NSData. *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Unacceptable type of value for attribute: property = "category"; desired type = NSData; given type = Swift.__SwiftDeferredNSArray; value = ( yo, gurt ).' terminating due to uncaught exception of type NSException CoreSimulator 1010.10 - Device: iPhone 16 18.0 (6879535B-3174-4025-AD37-ED06E60291AD) - Runtime: iOS 18.0 (22A3351) - DeviceType: iPhone 16 Message from debugger: killed @Model class MyModel: Identifiable, Equatable { @Attribute(.transformable(by: StringArrayTransformer.self)) var category: [String]? @Attribute(.transformable(by: StringArrayTransformer.self)) var amenities: [String]? var image: String? var parentChunck: HenricoPostDataChunk_V1? init(category: [String]?, amenities: [String]?) { self.category = category self.amenities = amenities } } class StringArrayTransformer: ValueTransformer { override func transformedValue(_ value: Any?) -> Any? { print(value) guard let array = value as? [String] else { return nil } let data = try? JSONSerialization.data(withJSONObject: array, options: []) print(data) return data } override func reverseTransformedValue(_ value: Any?) -> Any? { guard let data = value as? Data else { return nil } let string = (try? JSONSerialization.jsonObject(with: data, options: [])) as? [String] print(string) return string } override class func transformedValueClass() -> AnyClass { return NSData.self } override class func allowsReverseTransformation() -> Bool { return true } static func register() { print("regitsering") ValueTransformer.setValueTransformer(StringArrayTransformer(), forName: .stringArrayTransformerName) } } extension NSValueTransformerName { static let stringArrayTransformerName = NSValueTransformerName("StringArrayTransformer") }

Any idea what this message means? I assume it's coming from CloudKit, but the application seems to store and retrieve data properly.

I am struggling with exactly how to set up SwiftData relationships, beyond the single relationship model... Let's say I have a school. Each school offers a set of classes. Each class is taught by one teacher and attended by several students. Teachers may teach more than one class, but only at one school. Similarly students may attend more than one class, but only at one school. Classes themselves may be offered at more than one school. Can someone create a class for School, SchoolClass, Teacher, and Student with id, name, and relationships... I have tried it unsuccessfully about 10 different ways at this point. My most recent is below... I am struggling getting beyond a school listing in the app, and I'll cross that bridge next. I am just wondering if all the trouble I am having is because I am not smart with the class definitions. And wondering if this is to complex for SwiftData and CoreData is the requirement. This is not a real app, just my way of really trying to get a handle on Swift Data models and Navigation. I am very new to Swift, and will take any and all suggestions with enthusiasm! Thanks for taking the time. import Foundation import SwiftData @Model class School: Identifiable { var id: UUID = UUID() var name: String var mascot: String var teachers: [Teacher] var schoolClasses: [SchoolClass] init (name: String, mascot: String = "", teachers: [Teacher] = [], schoolClasses: [SchoolClass] = []) { self.name = name self.mascot = mascot self.teachers = teachers } class SchoolClass: Identifiable { var id: UUID = UUID() var name: String var teacher: Teacher? var students: [Student] = [] init (name: String, teacher: Teacher? = nil, students: [Student] = []) { self.name = name self.teacher = teacher self.students = students } } class Teacher: Identifiable { var id: UUID = UUID() var name: String var tenured: Bool var school: School? var students: [Student] = [] init (name: String, tenured: Bool = false, students: [Student] = []) { self.name = name self.tenured = tenured self.students = students } } class Student: Identifiable { var id: UUID = UUID() var name: String var grade: Int? var teacher: Teacher? init (name: String, grade: Int? = nil, teacher: Teacher? = nil) { self.name = name self.grade = grade self.teacher = teacher } } }

I tried to use the .deny deleteRule but it seems to have no effect. The toolbar button adds an item with a relationship to a category to the context. Swiping on the category deletes the category even though an item is referencing the category. There is also no error thrown when saving the context. It is as if the deleteRule was not there. For other deleteRules like .cascade, the provided sample code works as expected. import SwiftUI import SwiftData @Model class Category { var name: String @Relationship(deleteRule: .deny) var items: [Item] = [] init(name: String) { self.name = name } } @Model class Item { var name: String var category: Category? init(name: String, category: Category) { self.name = name self.category = category } } struct DenyDeleteRule: View { @Environment(\.modelContext) private var modelContext @Query private var categories: [Category] @Query private var items: [Item] var body: some View { List { Section("Items") { ForEach(items) { item in Text(item.name) } } Section("Categories") { ForEach(categories) { category in VStack(alignment: .leading) { Text(category.name).bold() ForEach(category.items) { item in Text("• \(item.name)") } } } .onDelete(perform: deleteCategory) } } .toolbar { Button("Add Sample") { let category = Category(name: "Sample") let item = Item(name: "Test Item", category: category) modelContext.insert(item) } } } func deleteCategory(at offsets: IndexSet) { for index in offsets { let category = categories[index] modelContext.delete(category) do { try modelContext.save() } catch { print(error) } } } } #Preview { NavigationStack { DenyDeleteRule() } .modelContainer(for: [Item.self, Category.self], inMemory: true) }

I have a SwiftUI document-based app that for the sake of this discussion stores accounting information: chart of accounts, transactions, etc. Each document is backed by a SwiftData DB. I'd like to incorporate search into the app so that users can find transactions matching certain criteria, so I went to Core Spotlight. Indexing & search within the app seem to work well. The issue is that Spotlight APIs appear to be App based & not Document based. I can't find a way to separate Spotlight data by document. I've tried having each document maintain a UUID as a document-specific identifier and include the identifier in every CSSearchableItem. When performing a query I filter the results with CSUserQueryContext.filterQueries that filter by the document identifier. That works to limit results to the specific file for search operations. Index updates via CSSearchableIndexDelegate.reindex* methods seem to be App-centric. A user may have file #1 open, but the delegate is being asked to update CSSearchableItems for IDs in other files. Is there a proper way to use Spotlight for in-app search with a document-based app? Is there a way to keep Spotlight-indexed data local within the app & not make it available across the system? I.e. I'd like to search within the app only. System-level searches should not surface this data.

I'm building a SwiftUI app using SwiftData. In my app I have a Customer model with an optional codable structure Contact. Below is a simplified version of my model: @Model class Customer { var name: String = "" var contact: Contact? init(name: String, contact: Contact? = nil) { self.name = name self.contact = contact } struct Contact: Codable, Equatable { var phone: String var email: String var allowSMS: Bool } } I'm trying to query all the Customers that have a contact with @Query. For example: @Query(filter: #Predicate<Customer> { customer in customer.contact != nil }) var customers: [Customer] However no matter how I set the predicate I always get an error: BugDemo crashed due to an uncaught exception NSInvalidArgumentException. Reason: keypath contact not found in entity Customer. How can I fix this so that I'm able to filter by contact not nil in my Model?

I would like to have a SwiftData predicate that filters against an array of PersistentIdentifiers. A trivial use case could filtering Posts by one or more Categories. This sounds like something that must be trivial to do. When doing the following, however: let categoryIds: [PersistentIdentifier] = categoryFilter.map { $0.id } let pred = #Predicate<Post> { if let catId = $0.category?.persistentModelID { return categoryIds.contains(catId) } else { return false } } The code compiles, but produces the following runtime exception (XCode 26 beta, iOS 26 simulator): 'NSInvalidArgumentException', reason: 'unimplemented SQL generation for predicate : (TERNARY(item != nil, item, nil) IN {}) (bad LHS)' Strangely, the same code works if the array to filter against is an array of a primitive type, e.g. String or Int. What is going wrong here and what could be a possible workaround?

If I set my build settings "default actor isolation" to MainActor, how do my @ModelActor actors and model classes need to look like ? For now, I am creating instances of my @ModelActor actors and passing my modelContext container and processing all data there. Everything stays in this context. No models are transferred back to MainActor. Now, after changing my project settings, I am getting a huge amount of warnings. Do I need to set all my model classes to non-isolated and the @ModelActor actor as well? Is there any new sample code to cover this topic ... did not find anything for now. Thanks in advance, Marc

I have an iOS app using SwiftData with VersionedSchema. The schema is synchronized with an CloudKit container. I previously introduced some model properties that I have now removed, as they are no longer needed. This results in the current schema version being identical to one of the previous ones (except for its version number). This results in the following exception: 'NSInvalidArgumentException', reason: 'Duplicate version checksums across stages detected.' So it looks like we cannot have a newer schema version with an identical content to an older schema version. The intuitive way would be to re-add the old (identical) schema version to the end of the "schemas" list property in the SchemaMigrationPlan, in order to signal that it is the newest one, and to add a migration stage back to it, thus: public enum MySchemaMigrationPlan: SchemaMigrationPlan { public static var schemas: [any VersionedSchema.Type] { [ SchemaV100.self, SchemaV101.self, SchemaV100.self ] } public static var stages: [MigrationStage] { [ migrateV100toV101, migrateV101toV100 ] } However, I am not sure if this is the right way to go, as previously, as I wanted to write unit tests for schema migration and rollback, I tried defining an inverse for each migration stage, so that I could trigger a migration and a rollback from a unit test, which resulted in an exception saying that it is not supported to downgrade a VersionedSchema. I must admit that I solved the original problem by introducing a dummy model property that I will later remove. What would have been the correct approach?

I have encountered the following error and reduced my code to the minimum necessary to reliably reproduce this error. Fatal error: Duplicate keys of type 'AnyHashable2' were found in a >Dictionary. This usually means either that the type violates Hashable's >requirements, or that members of such a dictionary were mutated after insertion. It occurs when instances of a swiftdata model are inserted (the error occurs reliably when inserting five or more instances. Fewer insertions seems to make the error either more rare or go away entirely) and a Picker with .menu pickerStyle is present. Any of the following changes prevents the error from occuring: adding id = UUID() to the Item class removing .tag(item) in the picker content using any pickerStyle other than .menu using an observable class instead of a swiftdata class I would greatly appreciate if anyone knows what exactly is going on here. Tested using XCode Version 16.4 (16F6), iPhone 16 Pro iOS 18.5 Simulator and iPhone 15 Pro iOS 18.5 real device. import SwiftUI import SwiftData @Model class Item { var name: String init(name: String) { self.name = name } } struct DuplicateKeysErrorView: View { @Environment(\.modelContext) private var modelContext @Query(sort: \Item.name) private var items: [Item] @State var selection: Item? = nil var body: some View { List { Picker("Picker", selection: $selection) { Text("Nil").tag(nil as Item?) ForEach(items) { item in Text(item.name).tag(item) } } .pickerStyle(.menu) Button("Add 5 items") { modelContext.insert(Item(name: UUID().uuidString)) modelContext.insert(Item(name: UUID().uuidString)) modelContext.insert(Item(name: UUID().uuidString)) modelContext.insert(Item(name: UUID().uuidString)) modelContext.insert(Item(name: UUID().uuidString)) } } .onAppear { try! modelContext.delete(model: Item.self) } } } #Preview { DuplicateKeysErrorView() .modelContainer(for: Item.self) }

We are trying to solve for the following condition with SwiftData + CloudKit: Lots of data in CloudKit Perform "app-reset" to clear data & App settings and start fresh. Reset data models with try modelContext.delete(model:_) myModel.count() confirms local deletion (0 records); but iCloud Console shows expectedly slow process to delete. Old CloudKit data is returning during the On Boarding process. Questions: • Would making a new iCloud Zone for each reset work around this, as the new zone would be empty? We're having trouble finding details about how to do this with SwiftData. • Would CKSyncEngine have a benefit over the default SwiftData methods? Open to hearing if anyone has experienced a similar challenge and how you worked around it!

Greetings i have an app that uses three different SwiftData models and i want to know what is the best way to use the them accross the app. I though a centralized behaviour and i want to know if it a correct approach.First let's suppose that the first view of the app will load the three models using the @Enviroment that work with @Observation. Then to other views that add data to the swiftModels again with the @Environment. Another View that will use the swiftData models with graph and datas for average and min and max.Is this a corrent way? or i should use @Query in every view that i want and ModelContext when i add the data. @Observable class CentralizedDataModels { var firstDataModel: [FirstDataModel] = [] var secondDataModel: [SecondDataModel] = [] var thirdDataModel: [ThirdDataModel] = [] let context: ModelContext init(context:ModelContext) { self.context = context } }