SwiftUI : NavigationStack in new iOS 18 TabView pushes twice when path in parameter

Hello,

With iOS 18, when NavigationStack is in new TabView, with path parameter containing current navigation state is set, the navigation destination view is pushed twice.

See below with example that pushes twice on iOS 18 but is correct on iOS 17

@MainActor
class NavigationModel: ObservableObject {
    static let shared = NavigationModel()
    
    @Published var selectedTab: String
    @Published var homePath: [Route]
    @Published var testPath: [Route]
}


struct ContentView: View {
    @StateObject private var navigationModel: NavigationModel = NavigationModel.shared
    
    var body: some View {
        TabView(selection: $navigationModel.selectedTab){
            HomeView()
                .tabItem {
                    Label("Home", systemImage: "house")
                }
                .tag("home")
            
            TestView()
                .tabItem {
                    Label("Test", systemImage: "circle")
                }
                .tag("test")
        }
    }
}


struct HomeView: View {
    @StateObject private var navigationModel: NavigationModel = NavigationModel.shared

    var body: some View {
        NavigationStack(path: $navigationModel.homePath){
            VStack{
                Text("home")
                NavigationLink(value: Route.test1("test1")){
                    Text("Go to test1")
                }
            }
            .navigationDestination(for: Route.self){ route in
                NavigationModelBuilder.findFinalDestination(route:route)
            }
        }
    }
}

I don't what causes the issue because it works well on iOS 16 and iOS 17. I think the path is somehow reset but I don't why (maybe by the TabView ?)

Note that the bug only occurs with TabView. Don't really know if it is a TabView bug or if it is on my side.

I filed a feedback with sample project FB14312064

Answered by brebispanique in 799115022

The issue seems to be fixed in iOS 18 beta 5

One thing I noticed is that I had some errant selection: parameters in some Lists and after removing them, the behavior stopped.

Has anyone found a workaround for this? I cannot have a NavigationStack inside a TabView without it double pushing.

I’m not familiar with all the details, but I found a workaround for this issue. Simply set the constant tabViewCustomization to the TabView.

.tabViewCustomization(.constant(TabViewCustomization()))
SwiftUI : NavigationStack in new iOS 18 TabView pushes twice when path in parameter
 
 
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