android-clear fragment after navigate in navigation component

Question

have some problem here.

let's say I have 3 fragment A-B-C. First i navigate from fragment A to B. Then from fragment B i want to navigate to fragment C and clear fragment B from stack. I need to clear it while navigate because i need to make sure the stack become A-C when the user in fragment C, if user click back, user will back to fragment A and there's also a button in fragment C to navigate to fragment B

please help me on this, need some advise to do this or if there any other solution please share it here.

Thanks

Answer 1

This question is tricky because of Jetpack Navigation's abysmal documentation on Conditional Navigation which should explain this subject but fails to do so, but the answer is actually quite simple.

All you need is popUpTo and popUpToInclusive.

<?xml version="1.0" encoding="utf-8"?>
<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/navigation"
    app:startDestination="@id/splash_graph"
    tools:ignore="UnusedNavigation">

    <navigation
        android:id="@+id/splash_graph"
        app:startDestination="@id/splash_fragment">

        <action
            android:id="@+id/splash_to_main_graph"
            app:destination="@id/main_graph"
            app:popUpTo="@id/splash_graph"
            app:popUpToInclusive="true" />

        <fragment
            android:id="@+id/splash_fragment"
            android:name="fqn.SplashFragment"
            tools:layout="@layout/splash_fragment" />
    </navigation>

    <navigation
        android:id="@+id/main_graph"
        app:startDestination="@id/fragment_a">

        <action
            android:id="@+id/fragment_a_to_fragment_b"
            app:destination="@id/fragment_b"
            app:enterAnim="@anim/slide_in_from_left"
            app:exitAnim="@anim/slide_out_to_right"
            app:popEnterAnim="@anim/slide_out_to_left"
            app:popExitAnim="@anim/slide_in_from_left" />

        <action
            android:id="@+id/fragment_b_to_fragment_c"
            app:destination="@id/fragment_c"
            app:enterAnim="@anim/slide_in_from_left"
            app:exitAnim="@anim/slide_out_to_right"
            app:popEnterAnim="@anim/slide_out_to_left"
            app:popExitAnim="@anim/slide_in_from_left"
            app:popUpTo="@id/fragment_b"
            app:popUpToInclusive="true" />

        <action
            android:id="@+id/fragment_c_to_fragment_b"
            app:destination="@id/fragment_b"
            app:enterAnim="@anim/slide_in_from_left"
            app:exitAnim="@anim/slide_out_to_right"
            app:popEnterAnim="@anim/slide_out_to_left"
            app:popExitAnim="@anim/slide_in_from_left"
            app:popUpTo="@id/fragment_c"
            app:popUpToInclusive="true" />

        <fragment
            android:id="@+id/fragment_a"
            android:name="fqn.FragmentA"
            tools:layout="@layout/fragment_a" />

        <fragment
            android:id="@+id/fragment_b"
            android:name="fqn.FragmentB"
            tools:layout="@layout/fragment_b" />

        <fragment
            android:id="@+id/fragment_c"
            android:name="fqn.FragmentC"
            tools:layout="@layout/fragment_c" />

    </navigation>
</navigation>

And then it should be as simple as

// FragmentA
findNavController().navigate(R.id.fragment_a_to_fragment_b)

// FragmentB
findNavController().navigate(R.id.fragment_b_to_fragment_c)

// FragmentC
findNavController().navigate(R.id.fragment_c_to_fragment_b)

And if you want to go back to FragmentA from FragmentB or FragmentC, you can call findNavController().popBackStack().