advanced patterns When Using Navigation Component with Nested Fragments in Android 13
I'm upgrading from an older version and I'm stuck on something that should probably be simple. Hey everyone, I'm running into an issue that's driving me crazy... I'm experiencing unexpected behavior when navigating between nested fragments using the Jetpack Navigation Component in Android 13. My main activity contains a fragment that hosts a navigation graph, and within that fragment, I have another nested fragment that I would like to navigate to. I've set up my navigation graph as follows: ```xml <fragment android:id="@+id/mainFragment" android:name="com.example.app.MainFragment" tools:layout="@layout/fragment_main"> <action android:id="@+id/action_mainFragment_to_nestedFragment" app:destination="@id/nestedFragment" /> </fragment> <fragment android:id="@+id/nestedFragment" android:name="com.example.app.NestedFragment" tools:layout="@layout/fragment_nested" /> ``` In my `MainFragment`, I try to navigate to `NestedFragment` like this: ```kotlin findNavController().navigate(R.id.action_mainFragment_to_nestedFragment) ``` However, when I attempt to navigate back from `NestedFragment` to `MainFragment`, I receive an behavior that states: ``` IllegalStateException: Fragment already added: NestedFragment ``` I’ve checked the fragment transactions and ensured that I'm not trying to add the same fragment multiple times. I also attempted to use `childFragmentManager` and navigate with the nested graph, but it didn't help either. Here's what I've tried: - Using `FragmentTransaction.replace()` instead of `navigate()`. - Ensuring that I call `findNavController()` on the correct fragment. - Clearing the back stack before navigating. Despite these efforts, I still encounter the same scenario. Could this be related to how the Navigation Component manages fragment lifecycles? Any insights on what I might be missing or how to handle nested fragment navigation correctly would be greatly appreciated. For context: I'm using Kotlin on macOS. Thanks in advance! This is happening in both development and production on Ubuntu 20.04. Any pointers in the right direction? My team is using Kotlin for this service.