Bug/Discussion: ViewModels are initialised multiple times?

[theedov]

I'm not sure if this is a bug tbh but I've noticed that @Observable objects are being initialised multiple times. So this @State private var viewModel = TimelineViewModel() for example would call TimelineViewModel.init multiple times.

Here is a forum post I could find about this "issue" https://forums.swift.org/t/observable-init-called-multiple-times-by-state-different-behavior-to-stateobject/70811/8 Apple also suggests initialising objects inside .task which would leave us with optionals everywhere... https://developer.apple.com/documentation/swiftui/state#Store-observable-objects

[theedov]

Another potential option is to conform viewmodel to ObservableObject and keep using @StateObject.

@Observable
final class ViewModel: ObservableObject {
....
}

@StateObject private var viewModel = ViewModel(()

[Dimillian]

FYI, I hear you, and I know the issue is there, but the workaround is just ugly. As I mostly don't do anything in my Observable init I don't really care. This doesn't create an issue as of today for me in this app.

[Wouter01]

You can fix this by using a custom property wrapper instead of @State: https://hachyderm.io/@groue/112320663017999822

[stonko1994]

Maybe switching to this approach would help: https://stackoverflow.com/a/71010187/2307466 🤔

[theedov]

FYI, I hear you, and I know the issue is there, but the workaround is just ugly. As I mostly don't do anything in my Observable init I don't really care. This doesn't create an issue as of today for me in this app.

It creates multiple instances of the same VM and doesn't seem to deinitialize all of the "redundant" ones though 🤔

[Dimillian]

Do you see that in the memory graph?

[theedov]

Think so.