TCA does not track perceptible state to do with NavigationStack on iOS 16 about swift-composable-architecture HOT 5 CLOSED

It looks like you’re missing WithPerceptionTracking inside your navigation stack’s destination closure, so iOS 16 cannot detect changes to the state inside the presented view.

from swift-composable-architecture.

It looks like you’re missing WithPerceptionTracking inside your navigation stack’s destination closure, so iOS 16 cannot detect changes to the state inside the presented view.

@lukeredpath

Thank you for your response. Based on your suggestion, I wrapped the navigation stack's destination closure with WithPerceptionTracking. However, there have been no changes.

I tried a different approach. I replaced NavigationStack with NavigationStackStore, and then it worked correctly on iOS16. I think there might be a slight difference between NavigationStack and NavigationStackStore.

NavigationStackStore(self.store.scope(state: \.path, action: \.path)) {
                    EmptyView()
                } destination: { store in
                    SwitchStore(store) {
                        switch $0 {
                        case .demo:
                            CaseLet(/RootStore.Path.State.demo,
                                     action: RootStore.Path.Action.demo) { _store in
                                DemoView(store: _store)
                            }
                        }
                    }
                }

from swift-composable-architecture.

@tsudo-kiroru the purple warnings are your clue that you're definitely missing a WithPerceptionTracking somewhere, that's why your view is not responding to state changes on iOS 16. Try expanding the backtrace of that error.

from swift-composable-architecture.

@tsudo-kiroru the purple warnings are your clue that you're definitely missing a WithPerceptionTracking somewhere, that's why your view is not responding to state changes on iOS 16. Try expanding the backtrace of that error.

@lukeredpath
Thank you for your reply. Based on your suggestion, I fixed my code as following below. I wrapped NavigationStack destination scope with WithPerceptionTracking. Then, the purple warnings disappeared. So I guess that state must be tracked.

NavigationStack(path: $store.scope(state: \.path, action: \.path)
                ) {
                    EmptyView()
                } destination: { destination in
                    WithPerceptionTracking {
                        let scope = destination.case
                        switch scope {
                        case let .demo(store):
                            DemoView(store: store)
                        }
                    }
                }

However, the navigation feature does not work correctly on iOS 16. There seems to be a difference between iOS 16 and iOS 17(As same as capturing movie).
It becomes harder to find the problem because no errors or warnings occur.

from swift-composable-architecture.

Hi @tsudo-kiroru, I believe this is just a problem with vanilla SwiftUI in general. The following code snippet works fine in iOS 17, but does not work in iOS 16:

class Model: ObservableObject {
  @Published var values: [Int] = []
}

struct ParentView: View {
  @StateObject var model = Model()

  var body: some View {
    Form {
      Button("Open") {
        model.values.append(1)
      }
      .sheet(
        isPresented: Binding(
          get: { !model.values.isEmpty },
          set: { if !$0 { model.values = [] } }
        )
      ) {
        NavigationStack(path: $model.values) {
          EmptyView()
          .navigationDestination(for: Int.self) { int in
            Form {
              Button("Push") {
                model.values.append(.random(in: 0...1_000))
              }
            }
          }
        }
      }
    }
  }
}

Since this is not a TCA issue I am going to convert it to a discussion, but please feel free to continue the conversation over there.

from swift-composable-architecture.