@State and "subview" also do not like each other ;-)

mlm

Hi,

it seems that I have run into a similar problem as with my other @State problem.

I have created a small sample project illustrating the issue over here.

It is very similar to the other issue with .fileimporter, since it is again that a @State variable does not properly reflect an update done in onAppear. Below (or in the sample project) is the relevant coding. Unfortunately I have still not enough understanding of the inner workings to fix it myself ;-(...

import Adwaita

@main
struct IssueWithState: App {
    let app = AdwaitaApp(id: "de.virtualfridge.issueWithState")

    @State private var text = "This will be replaced"

    var scene: Scene {
        Window(id: "main") { window in
            VStack {
                Text(Loc.helloWorld)
                    .padding()
                Text(text)
                    .padding()
                    .onAppear { text = "Not in extra view struct works" }
                OtherView()
                    .padding()
            }
            .topToolbar { ToolbarView(app: app, window: window) }
        }
        .defaultSize(width: 450, height: 300)
    }
}

struct OtherView: View {
    @State private var text = "This should not be there."

    var view: Body {
        Text(text)
            .padding()
            .onAppear { text = "It's good now" }
    }
}

Thank you for your support!

Cheers, Michael

david-swift

Poor @State doesn't seem to be very popular ;)

Thanks for reporting the issue!

I will look into this at some point when I am less busy, but I wanted to ask where one would face this issue. I mean, one can set it directly (@State private var text = "It's good now") to set it directly or one fetches the data and sets it asynchronously.

If you need a work around, set the new label asynchronously:

.onAppear { Task { text = "It's good now" } }

Cheers, David

mlm

No no, @State is just too popular ;-)

Perfect, the workaround will do it for now.

To answer your question, why you would want to do it (and now that I think about it, the reason might not be relevant to Aparoksha, since it is very much dependent how the frameworks work internally):
If you wanted to make a @State variable dependent on a value coming from outside the View struct, the obvious way to dot it, would be making a custom init method and initialize the @State variable there. But this would not work as expected when the parent view was re-created. So the workaround was, to set a "normal" variable in the custom initalizer and set the state either in .onAppear or .task.
Another reason to set a @State in .onAppear might be, that the creation of the View struct and when it appears on the screen might be at very different points in time, but you want to initialize something depending on when exactly it will become visible.

Cheers, Michael