java.lang.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:

java.lang.IllegalArgumentException: navigation destination XXX
is unknown to this NavController

Every other navigation works fine except this particular one.

I use:

findNavContoller()

extension function of Fragment to get access to the navControler.

Any help will be appreciated.

Answer 1

In my case, if the user clicks the same view twice very very quickly, this crash will occur. So you need to implement some sort of logic to prevent multiple quick clicks... Which is very annoying, but it appears to be necessary.

You can read up more on preventing this here: Android Preventing Double Click On A Button

Edit 3/19/2019: Just to clarify a bit further, this crash is not exclusively reproducible by just "clicking the same view twice very very quickly". Alternatively, you can just use two fingers and click two (or more) views at the same time, where each view has their own navigation that they would perform. This is especially easy to do when you have a list of items. The above info on multiple click prevention will handle this case.

Answer 2

Check currentDestination before calling navigate might be helpful.

For example, if you have two fragment destinations on the navigation graph fragmentA and fragmentB, and there is only one action from fragmentA to fragmentB. calling navigate(R.id.action_fragmentA_to_fragmentB) will result in IllegalArgumentException when you were already on fragmentB. Therefor you should always check the currentDestination before navigating.

if (navController.currentDestination?.id == R.id.fragmentA) {
    navController.navigate(R.id.action_fragmentA_to_fragmentB)
}

Answer 3

You can check requested action in current destination of navigation controller

fun NavController.navigateSafe(
        @IdRes resId: Int,
        args: Bundle? = null,
        navOptions: NavOptions? = null,
        navExtras: Navigator.Extras? = null
) {
    val action = currentDestination?.getAction(resId)
    if (action != null) navigate(resId, args, navOptions, navExtras)
}

Answer 4

In my case I was using a custom back button for navigating up. I called onBackPressed() in stead of the following code

findNavController(R.id.navigation_host_fragment).navigateUp()

This caused the IllegalArgumentException to occur. After I changed it to use the navigateUp() method in stead, I didn't have a crash again.

Answer 5

It could also happen if you have a Fragment A with a ViewPager of Fragments B And you try to navigate from B to C

Since in the ViewPager the fragments are not a destination of A, your graph wouldn't know you are on B.

A solution can be to use ADirections in B to navigate to C

Answer 6

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 7

It seems like you are clearing task. An app might have a one-time setup or series of login screens. These conditional screens should not be considered the starting destination of your app.

https://developer.android.com/topic/libraries/architecture/navigation/navigation-conditional

Answer 8

What I did to prevent the crash is the following:

I have a BaseFragment, in there I've added this fun to ensure that the destination is known by the currentDestination:

fun navigate(destination: NavDirections) = with(findNavController()) {
    currentDestination?.getAction(destination.actionId)
        ?.let { navigate(destination) }
}

Worth noting that I'm using the SafeArgs plugin.

Answer 9

I caught this exception after some renames of classes. For example: I had classes called FragmentA with @+is/fragment_a in navigation graph and FragmentB with @+id/fragment_b. Then I deleted FragmentA and renamed FragmentB to FragmentA. So after that node of FragmentA still stayed in navigation graph, and android:name of FragmentB's node was renamed path.to.FragmentA. I had two nodes with the same android:name and different android:id, and the action I needed were defined on node of removed class.

Answer 10

TL;DR Wrap your navigate calls with try-catch (simple way), or make sure there will be only one call of navigate in short period of time. This issue likely won't go away. Copy bigger code snippet in your app and try out.

Hello. Based on a couple of useful responses above, I would like to share my solution that can be extended.

Here is the code that caused this crash in my application:

@Override
public void onListItemClicked(ListItem item) {
    Bundle bundle = new Bundle();
    bundle.putParcelable(SomeFragment.LIST_KEY, item);
    Navigation.findNavController(recyclerView).navigate(R.id.action_listFragment_to_listItemInfoFragment, bundle);
}

A way to easily reproduce the bug is to tap with multiple fingers on the list of items where click on each item resolves in the navigation to the new screen (basically the same as people noted - two or more clicks in a very short period of time). I noticed that:

1. First navigate invocation always works fine;
2. Second and all other invocations of the navigate method resolve in IllegalArgumentException.

From my point of view, this situation may appear very often. Since the repeating of code is a bad practice and it is always good to have one point of influence I thought of the next solution:

public class NavigationHandler {

public static void navigate(View view, @IdRes int destination) {
    navigate(view, destination, /* args */null);
}

/**
 * Performs a navigation to given destination using {@link androidx.navigation.NavController}
 * found via {@param view}. Catches {@link IllegalArgumentException} that may occur due to
 * multiple invocations of {@link androidx.navigation.NavController#navigate} in short period of time.
 * The navigation must work as intended.
 *
 * @param view        the view to search from
 * @param destination destination id
 * @param args        arguments to pass to the destination
 */
public static void navigate(View view, @IdRes int destination, @Nullable Bundle args) {
    try {
        Navigation.findNavController(view).navigate(destination, args);
    } catch (IllegalArgumentException e) {
        Log.e(NavigationHandler.class.getSimpleName(), "Multiple navigation attempts handled.");
    }
}

}

And thus the code above changes only in one line from this:

Navigation.findNavController(recyclerView).navigate(R.id.action_listFragment_to_listItemInfoFragment, bundle);

to this:

NavigationHandler.navigate(recyclerView, R.id.action_listFragment_to_listItemInfoFragment, bundle);

It even became a little bit shorter. The code was tested in the exact place where the crash occurred. Did not experience it anymore, and will use the same solution for other navigations to avoid the same mistake further.

Any thoughts are welcome!

What exactly causes the crash

Remember that here we work with the same navigation graph, navigation controller and back-stack when we use method Navigation.findNavController.

We always get the same controller and graph here. When navigate(R.id.my_next_destination) is called graph and back-stack changes almost instantly while UI is not updated yet. Just not fast enough, but that is ok. After back-stack has changed the navigation system receives the second navigate(R.id.my_next_destination) call. Since back-stack has changed we now operate relative to the top fragment in the stack. The top fragment is the fragment you navigate to by using R.id.my_next_destination, but it does not contain next any further destinations with ID R.id.my_next_destination. Thus you get IllegalArgumentException because of the ID that the fragment knows nothing about.

This exact error can be found in NavController.java method findDestination.

Answer 11

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.