Since Xcode 15 beta 5, making a class with the @Observable macro no longer requires all properties to have an initialization value, as seen in the video. Just put an init that collects the properties and everything works correctly. @Observable final class Score: Identifiable { let id: Int var title: String var composer: String var year: Int var length: Int var cover: String var tracks: [String] init(id: Int, title: String, composer: String, year: Int, length: Int, cover: String, tracks: [String]) { self.id = id self.title = title self.composer = composer self.year = year self.length = length self.cover = cover self.tracks = tracks } } But there is a problem: the @Observable macro makes each property to integrate the @ObservationTracked macro that seems not to conform the types to Equatable, and in addition, to Hashable. Obviously, being a feature of each property, it is not useful to conform the class in a forced way with the static func == or with the hash(into:Hasher) function that conforms both protocols. That any class we want to be @Observable does not conform to Hashable, prevents any instance with the new pattern to be usable within a NavigationStack using the data driven navigation bindings and the navigationDestination(for:) modifier. I understand that no one has found a solution to this. If you have found it it would be great if you could share it but mainly I am making this post to invoke the mighty developers at Apple to fix this bug. Thank you very much. P.S. - I also posted a Feedback (FB12535713), but no one replies. At least that I see.

Hi. The binding in a ForEach or List view doesn't work anymore when using the @Observable macro to create the observable object. For example, the following are the modifications I introduced to the Apple's example called "Migrating from the Observable Object Protocol to the Observable Macro" https://developer.apple.com/documentation/swiftui/migrating-from-the-observable-object-protocol-to-the-observable-macro struct LibraryView: View { @Environment(Library.self) private var library var body: some View { List($library.books) { $book in BookView(book: book) } } } All I did was to add the $ to turn the reference to library.books into a binding but I got the error "Cannot find '$library' in scope" Is this a bug or the procedure to use binding in lists changed? Thanks

Previously, it was recommended to use the @MainActor annotation for ObservableObject implementation. @MainActor final class MyModel: ObservableObject { let session: URLSession @Published var someText = "" init(session: URLSession) { self.session = session } } We could use this as either a @StateObject or @ObservedObject: struct MyView: View { @StateObject let model = MyModel(session: .shared) } By moving to Observation, I need to the @Observable macro, remove the @Published property wrappers and Switch @StateObject to @State: @MainActor @Observable final class MyModel { let session: URLSession var someText = "" init(session: URLSession) { self.session = session } } But switching from @StateObject to @State triggers me an error due to a call to main-actor isolated initialiser in a synchronous nonisolated context. This was not the case with @StateObject of @ObservedObject. To suppress the warning I could : mark the initializer as nonisolated but it is not actually what I want Mark the View with @MainActor but this sounds odd Both solutions does not sound nice to my eye. Did I miss something here?

The code for @State doesn't seem to work. struct DonutListView: View { var donutList: DonutList @State private var donutToAdd: Donut? var body: some View { List(donutList.donuts) { DonutView(donut: $0) } Button("Add Donut") { donutToAdd = Donut() } .sheet(item: $donutToAdd) { // <-- would need a "donut in" TextField("Name", text: $donutToAdd.name) // <-- donutToAdd is optional and I'm not sure how it would be unwrapped Button("Save") { donutList.donuts.append(donutToAdd) donutToAdd = nil } Button("Cancel") { donutToAdd = nil } } } } Does anyone have a fix for this? Thanks, Dan!

I'm in the process of migrating to the Observation framework but it seems like it is not compatible with didSet. I cannot find information about if this is just not supported or a new approach needs to be implemented? import Observation @Observable class MySettings { var windowSize: CGSize = .zero var isInFullscreen = false var scalingMode: ScalingMode = .scaled { didSet { ... } } ... } This code triggers this error: Instance member 'scalingMode' cannot be used on type 'MySettings'; did you mean to use a value of this type instead? Anyone knows what needs to be done? Thanks!