swiftui - How to pass same object to multiple subviews?

Question

For each element in my database I want to display a navigation link. The destination and the label of each element should get the same object passed. Now I'm creating for each view a new object. Therefore the UI is not consistent. How can I solve this problem and create exactly one viewModel for each element in the database and pass this to the two subviews?

ForEach(database.decks) { elem in 
    // looking for a solution like: let viewModel = ViewModel(deck: deck) and pass this
    NavigationLink (
        destination: DeckDetailView(viewModel: ViewModel(deck: elem)), // <----- this viewModel
        label: {
            ZStack(alignment: .topTrailing) {
                DeckItem(viewModel: ViewModel(deck: elem)) // <----- and this viewModel should be the same!
            }
        }
    )
}
                                               
                                            

question from:https://stackoverflow.com/questions/65884619/how-to-pass-same-object-to-multiple-subviews

Answer 1

The good reuse design (and simplified view hierarchy, and update when needed explicitly) is to separate that link in standalone view for row, like

ForEach(database.decks) { elem in 
   DeckRowView(elem: elem)
}

and row

struct DeckRowView: View {
  @ObservedObject var vm: ViewModel

  init(elem: Deck) {
     self.vm = ViewModel(deck: elem)
  }

  var body: some View {
    NavigationLink (
        destination: DeckDetailView(viewModel: self.vm),
        label: {
            ZStack(alignment: .topTrailing) {
                DeckItem(viewModel: self.vm)
            }
        }
    )
  }
}