title: Passing An ObservedObject To Nested Child Views SwiftUI (SwiftUI Data Flow)
body: <p>I'm trying to understand why passing an @ObservedObject variable does not work for nested child views. The data is able to be passed but the changes only reflects at the root view where the @ObservedObject variable was created. The changes don't show in the subviews. Looking at Apple documentation (which has been updated for Xcode beta 5), the answer seems to be to create both an environment object and a regular variable in order to get the correct index from the environment object. Here is Apples <a href="https://developer.apple.com/tutorials/swiftui/handling-user-input" rel="noreferrer">example</a>.</p>
  
  <p>My understanding is that an @ObservedObject can be used to reference a variable from multiple views, but if you want the data to be accessible from any view then you should use an environment object. Therefore I believe that passing the @ObservedObject should be possible. The issue I believe is happening is that since ScreenTwo is passing the @Binding variable to DetailsView and that is what's causing a problem. To solve this I would think you need to keep passing the full @ObservedObject, but then again you would need some type of regular variable to get the proper index.</p>
  
  <p>I feel like all of this should be much more straightforward.</p>
  
  <pre><code>import SwiftUI
  import Combine
  
  struct Sport: Identifiable{
      var id = UUID()
      var name : String
      var isFavorite = false
      var school : String
  }
  
  final class SportData: ObservableObject  {
      @Published var store =
          [
              Sport(name: "soccer", isFavorite: false, school: "WPI"),
              Sport(name: "tennis", isFavorite: false, school: "WPI"),
              Sport(name: "swimming", isFavorite: true, school: "WPI"),
              Sport(name: "running", isFavorite: true, school: "RIT"),
      ]
  }
  
  struct Testing: View {
      @ObservedObject var sports = SportData()
  
      var body: some View {
          NavigationView{
              List{
                  ForEach($sports.store){ sport in
                      NavigationLink(destination: ScreenTwo(sport: sport)){
                          HStack {
                              Text(sport.value.name)
                              Spacer()
                              Text(sport.value.isFavorite.description)
                          }
                      }
                  }
              }
          }.navigationBarTitle("Settings")
      }
  }
  
  struct ScreenTwo : View{
      @Binding var sport : Sport
  
      var body: some View{
          NavigationLink(destination: DetailsView(sport: $sport)){
              Text(sport.isFavorite.description)
          }
      }
  }
  
  struct DetailsView: View {
      @Binding var sport : Sport
  
      var body: some View {
          Button(action: {
              self.sport.isFavorite.toggle()
              self.sport.name = "Ricky"
          }) {
              Text(sport.isFavorite.description)
              Text(sport.name)
          }
      }
  }
  
  
  
  #if DEBUG
  struct Testing_Previews: PreviewProvider {
      static var previews: some View {
          Testing()
      }
  }
  #endif
  </code></pre>