Hi!

I do not understand this behavior: When dismissing a fullScreenCover using a variable inside an ObservableObject (lines commented with 1.-) it shows the "Publishing changes from within view updates is not allowed, this will cause undefined behavior." message in the console, but using a @State variable (lines commented with 2.-) does not show the warning. Here is the example code:

import SwiftUI

final class DismissWarningVM: ObservableObject {
    @Published var showAnotherView = false
}

struct DismissWarningView: View {
    @StateObject private var dismissWarningVM = DismissWarningVM()

    @State private var showAnotherView = false

    var body: some View {
        VStack {
            HStack {
                Spacer()
                Button {
                    // 1.- This line provokes the warning
                    dismissWarningVM.showAnotherView = true
                    // 2.- This line DO NOT provokes the warning
                    //showAnotherView = true
                } label: {
                    Text("Show")
                }
            }
            .padding(.trailing, 20)
            Spacer()
            Text("Main view")
            Spacer()

        }
        .frame(maxWidth: .infinity, maxHeight: .infinity)
        .background(.white)
        // 1.- This line provokes the warning
        .fullScreenCover(isPresented: $dismissWarningVM.showAnotherView) {
        // 2.- This line DO NOT provokes the warning
        //.fullScreenCover(isPresented: $showAnotherView) {
            AnotherView()
        }
    }
}

struct AnotherView: View {
    @Environment(\.dismiss) var dismiss

    var body: some View {
        VStack(spacing: 30) {
            Text("Another view")
            Button {
                dismiss()
            } label: {
                Text("Dismiss")
                    .foregroundColor(.red)
            }
        }
        .frame(maxWidth: .infinity, maxHeight: .infinity)
        .ignoresSafeArea()
    }
}

Can anyone help me?

Thanks!

Hi!

Thank you for your answer. I was trying with XCode 14.0.1 and getting the warning but after updating to XCode 14.1 the warning dissappear.

Thank you!

After 14.1 the complier libray mark all @StateObject with @MainActor if you added this to the class then you would not got the warning

@MainActor
class NewObject: ObservableObject {

}

or

@MainActor @StateObject var newObject = NewObject()

@NigelGee I tried adding @MainActor to the view model class but still get the warning. When I get some time I'll try to install again the version 14.0.1 and try "@MainActor @StateObject var newObject = NewObject()"

Thanks!