struct ContentView: View {
    @ObservedObject var model = ContentViewModel()

    var body: some View {
        Text(String(model.isReady))
            .font(.headline)
        SaleView(isOn: $model.isReady)  // generates a Binding to 'isReadyForSale' property
    }
}


class ContentViewModel: ObservableObject {
    @Published var isReady = true
}


struct SaleView: View {
    @Binding var isOn: Bool

    var body: some View {
//        Toggle("Ready for Sale", isOn: $isOn)
        
        Text("change")
            .onTapGesture {
                isOn.toggle()
            }
    }
}