How to check if a NavigationPath contains an NSManagedObject value?

Question

Suppose we have two very basic classes:

• a NSManagedObject class called Item
• and an ObservableObject class called Navigation to handle a NavigationPath

final class Navigation: ObservableObject {
    @Published var path = NavigationPath()
}

I am looking to disable a NavigationLink when the NavigationPath contains a certain Item element, as shown in this example:

struct ContentView: View {
    @StateObject private var navigation = Navigation()
    
    @Environment(\.managedObjectContext) private var viewContext

    @FetchRequest(sortDescriptors: [NSSortDescriptor(keyPath: \Item.timestamp, ascending: true)], animation: .default)
    private var items: FetchedResults<Item>

    var body: some View {
        NavigationStack(path: $navigation.path) {
            List(items) { item in
                NavigationLink(value: item) {
                    Text("Item at \(item.timestamp!.formatted())")
                }
                .disabled(navigation.path.contains(/* some Item */))
            }
        }
        .environmentObject(navigation)
    }
}

However to my surprise a NavigationPath has no contains() function. Any ideas please?

Answer 1

Try changing

 @Published var path = NavigationPath()

To

 @Published var path: [Item] = []