NavigationStack and programmatic navigationThese are the lesson notes for this day. Its build-along tutorial and flash cards have not been written yet.
NavigationStack and programmatic navigationNavigationStack manages a stack of screens. You push a screen with NavigationLink(value:), and you say once, with .navigationDestination(for:), which screen each type of value leads to. The contents of the stack can be bound to an array that you own, called the path. Navigation then becomes ordinary data: append a value to push, remove one to pop, empty the array to return to the root, and assign several values at once to open a deep link.
Coming from UIKit, this replaces pushViewController and coordinator objects. Because the path is plain data, you can save and restore it, and you can unit test navigation logic with no user interface at all.
struct TripsList: View {
let trips: [Trip]
@State private var path: [Trip] = [] // the navigation stack, as data
var body: some View {
NavigationStack(path: $path) {
List(trips) { trip in
NavigationLink(trip.name, value: trip) // push by value
}
.navigationDestination(for: Trip.self) { trip in
Button("Back to start") { path.removeAll() } // pop to root
.navigationTitle(trip.name)
}
}
}
}Build a flow of list → detail → sub-detail. Add a button on the deepest screen that returns to the root by clearing the path, and a button on the root that jumps straight to a sub-detail screen.
After this lesson you should be able to answer.navigationDestination(for:) do, and where do you attach it?