@EnvironmentObject disappearing when used on modal sheet

Question

There seems to be a bug in #SwiftUI where @EnvironmentObject will be no longer available if the user pulls down a modal sheet to close it, but cancels the gesture leaving it open.

Actual error:

SwiftUI:0: Fatal error: No ObservableObject of type found. A View.environmentObject(_:) for may be missing as an ancestor of this view.

It doesn't happen all the time, but finding it not too hard to reproduce. Does anyone know of a fix?

You need explicitly inject environment object into sheet content, because it is in different view hierarchy. — Asperi, May 28 '21 at 17:20
See this for example https://stackoverflow.com/a/59658129/12299030. — Asperi, May 28 '21 at 17:41
Interesting, thank you @Asperi. Could you make that an answer? I'll be happy to mark it as accepted. — Eneko Alonso, May 28 '21 at 17:53

score 3 · Answer 1 · answered May 29 '21 at 06:17

Just append a .environmentObject(env) to the presented sheet and it fixes your problem.

In more detail:

@EnvrironmentObject var currentEnvironment: SomeEnvironment
@State var isSheetPresented: Bool = false

var body: some View {
    VStack {
        // ...
    }
    .sheet(isPresented: $isSheetPresented) {
        OtherView()
            .environmentObject(currentEnvironment)
    }
}

To reproduce the issue, you can use the drag gesture to drag the sheet halfway to close it, and just release it. (in a way that it does not close...)

About the situation, I once read that it is somehow a bug. But I also read that this is intended. To me, it seems that it is a bug because the condition that it happens in, feels not right to me.

@EnvironmentObject disappearing when used on modal sheet

1 Answers1