IllegalArgumentException: navigation destination xxx is unknown to this NavController

Question

I am having issue with the new Android Navigation Architecture component when I try to navigate from one Fragment to another, I get this weird error:

Answer 1

In my case, I had multiple nav graph files and I was trying to move from 1 nav graph location to a destination in another nav graph.

For this we have to include the 2nd nav graph in the 1st one like this

<include app:graph="@navigation/included_graph" />

and add this to your action:

<action
        android:id="@+id/action_fragment_to_second_graph"
        app:destination="@id/second_graph" />

where second_graph is :

<navigation xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/second_graph"
    app:startDestination="@id/includedStart">

in the second graph.

More info here

Answer 2

In order to avoid this crash one of my colleagues wrote a small library which exposes a SafeNavController, a wrapper around the NavController and handles the cases when this crash occurs because of multiple navigate commands at the same time.

Here is a short article about the whole issue and the solution.

You can find the library here.

Answer 3

This happened to me, my issue was I was clicking a FAB on tab item fragment. I was trying to navigate from one of tab item fragment to another fragment.

But according to Ian Lake in this answer we have to use tablayout and viewpager, no navigation component support. Because of this, there is no navigation path from tablayout containing fragment to tab item fragment.

ex:

containing fragment -> tab layout fragment -> tab item fragment -> another fragment

Solution was to create a path from tab layout containing fragment to intended fragment ex: path: container fragment -> another fragment

Disadvantage:

• Nav graph no longer represent user flow accurately.

Answer 4

In my case the bug ocurred because I had a navigation action with the Single Top and the Clear Task options enabled after a splash screen.

Answer 5

It seems that mixing fragmentManager control of the backstack and Navigation Architecture control of the backstack can cause this issue also.

For example the original CameraX basic sample used fragmentManager backstack navigation as below and it appears as if it did not correctly interact with Navigation:

// Handle back button press
        view.findViewById<ImageButton>(R.id.back_button).setOnClickListener {
            fragmentManager?.popBackStack()
        }

If you log the 'current destination' with this version before moving from the main fragment (the camera fragment in this case) and then log it again when you return to the main fragment, you can see from the id in the logs that the id is not the same. At a guess, the Navigation updated it when moving to the fragment and the fragmntManager did not then update it again when moving back. From the logs:

Before: D/CameraXBasic: currentDest?: androidx.navigation.fragment.FragmentNavigator$Destination@b713195

After: D/CameraXBasic: currentDest?: androidx.navigation.fragment.FragmentNavigator$Destination@9807d8f

The updated version of CameraX basic sample uses Navigation to return like this:

 // Handle back button press
        view.findViewById<ImageButton>(R.id.back_button).setOnClickListener {
            Navigation.findNavController(requireActivity(), R.id.fragment_container).navigateUp()
        }

This works correctly and the logs show the same id when back at the main fragment.

Before: D/CameraXBasic: currentDest?: androidx.navigation.fragment.FragmentNavigator$Destination@b713195

After: D/CameraXBasic: currentDest?: androidx.navigation.fragment.FragmentNavigator$Destination@b713195

I suspect the moral of the story, at least at this time, is to be very careful mixing Navigation with fragmentManager navigation.

Answer 6

I wrote this extensions

fun Fragment.navigateAction(action: NavDirections) {
    val navController = this.findNavController()
    if (navController.currentDestination?.getAction(action.actionId) == null) {
        return
    } else {
        navController.navigate(action)
    }
}