androidandroid-fragmentsandroid-architecture-componentsandroid-architecture-navigation

How to clear navigation Stack after navigating to another fragment in Android


I am using The new Navigation Architecture Component in android and I am stuck in clearing the navigation stack after moving to a new fragment.

Example: I am in the loginFragment and I want this fragment to be cleared from the stack when I navigate to the home fragment so that the user will not be returned back to the loginFragment when he presses the back button.

I am using a simple NavHostFragment.findNavController(Fragment).navigate(R.id.homeFragment) to navigate.

Current Code :

mAuth.signInWithCredential(credential)
            .addOnCompleteListener(getActivity(), new OnCompleteListener<AuthResult>() {
                @Override
                public void onComplete(@NonNull Task<AuthResult> task) {
                    if (task.isSuccessful()) {
                        NavHostFragment.findNavController(LoginFragment.this).navigate(R.id.homeFragment);
                    } else {
                        Log.w(TAG, "signInWithCredential:failure", task.getException());
                    }
                }
            });

I tried using the NavOptions in the navigate(), but the back button is still sending me back to the loginFragment

NavOptions.Builder navBuilder = new NavOptions.Builder();
NavOptions navOptions = navBuilder.setPopUpTo(R.id.homeFragment, false).build();   
             NavHostFragment.findNavController(LoginFragment.this).navigate(R.id.homeFragment, null, navOptions);

Solution

  • First, add attributes app:popUpTo='your_nav_graph_id' and app:popUpToInclusive="true" to the action tag.

    <fragment
        android:id="@+id/signInFragment"
        android:name="com.glee.incog2.android.fragment.SignInFragment"
        android:label="fragment_sign_in"
        tools:layout="@layout/fragment_sign_in" >
        <action
            android:id="@+id/action_signInFragment_to_usersFragment"
            app:destination="@id/usersFragment"
            app:launchSingleTop="true"
            app:popUpTo="@+id/main_nav_graph"
            app:popUpToInclusive="true" />
    </fragment>
    

    Second, navigate to the destination, using above action as parameter.

    findNavController(fragment).navigate(
         SignInFragmentDirections.actionSignInFragmentToUserNameFragment())
    

    See the docs for more information.

    NOTE: If you navigate using method navigate(@IdRes int resId), you won't get the desired result. Hence, I used method navigate(@NonNull NavDirections directions).