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il...@google.com
ma...@gmail.com
Oh I forgot to mention that I thought it might be connected to this issue:
ch...@moqi.co.uk
Please provide a minimal sample project along with the minimal steps to recreate the issue in the project.
il...@google.com
Sorry for the delay. I got a working example here:
I poked into it a little bit and it seems to be connected to
Steps to reproduce:
- Navigate from Second Fragment to Child nav graph (with non-nullable parameters).
- Navigate to Third fragment using SafeArgs and the app crashes.
Crash log:
Process: cz.dels.issues, PID: 1743
java.lang.NullPointerException: null cannot be cast to non-null type kotlin.Long
at androidx.navigation.NavType$Companion$LongType$1.get(NavType.kt:352)
at androidx.navigation.NavType$Companion$LongType$1.get(NavType.kt:342)
at androidx.navigation.NavArgument.verify(NavArgument.kt:76)
at androidx.navigation.NavDestination.addInDefaultArgs(NavDestination.kt:502)
at androidx.navigation.NavController.addEntryToBackStack(NavController.kt:1865)
at androidx.navigation.NavController.addEntryToBackStack$default(NavController.kt:1813)
at androidx.navigation.NavController$navigate$4.invoke(NavController.kt:1721)
at androidx.navigation.NavController$navigate$4.invoke(NavController.kt:1719)
at androidx.navigation.NavController$NavControllerNavigatorState.push(NavController.kt:287)
at androidx.navigation.fragment.FragmentNavigator.navigate(FragmentNavigator.kt:246)
at androidx.navigation.fragment.FragmentNavigator.navigate(FragmentNavigator.kt:162)
at androidx.navigation.NavController.navigateInternal(NavController.kt:260)
at androidx.navigation.NavController.navigate(NavController.kt:1719)
at androidx.navigation.NavController.navigate(NavController.kt:1545)
at androidx.navigation.NavController.navigate(NavController.kt:1472)
at androidx.navigation.NavController.navigate(NavController.kt:1930)
at cz.dels.issues.SecondFragment.onViewCreated$lambda-0(SecondFragment.kt:38)
at cz.dels.issues.SecondFragment.$r8$lambda$XDYnOS_cYrafiNQ5rcCu1WCn0IE(Unknown Source:0)
at cz.dels.issues.SecondFragment$$ExternalSyntheticLambda0.onClick(Unknown Source:2)
Note: If in step 2 SaveArgs is not used then navigation works correctly. More information is here:
ap...@google.com
Ups a typo: Navigate from Second First Fragment to Child nav graph (with non-nullable parameters).
Note: sorry for the spam but I am not able to edit my own comment.
Description
android.arch.navigation:navigation-fragment-ktx
android.arch.navigation:navigation-ui-ktx
Version used:
1.0.0-alpha05
Devices/Android versions reproduced on:
-SM-A510F, Android 7.0
-Emulator x86_64 API 28
Sample project:
Description:
Having this structure:
nav_graph.xml
<navigation
android:id="@+id/nav_graph"
app:startDestination="@id/startFragment">
<fragment
android:id="@+id/startFragment"
android:name="com.example.navbug.StartFragment"
android:label="StartFragment"
tools:layout="@layout/fragment_start">
<action
android:id="@+id/action_startFragment_to_nested_nav_graph"
app:destination="@id/nested_nav_graph" />
</fragment>
<include app:graph="@navigation/nested_nav_graph" />
</navigation>
nested_nav_graph.xml
<navigation
android:id="@+id/nested_nav_graph"
app:startDestination="@id/nestedStartFragment">
<fragment
android:id="@+id/nestedStartFragment"
android:name="com.example.navbug.NestedStartFragment"
android:label="NestedStartFragment">
<action
android:id="@+id/action_nestedStartFragment_to_nestedSecondFragment"
app:destination="@id/nestedSecondFragment"
app:popUpTo="@+id/nestedStartFragment"
app:popUpToInclusive="true" />
</fragment>
<fragment
android:id="@+id/nestedSecondFragment"
android:name="com.example.navbug.NestedSecondFragment"
android:label="NestedSecondFragment" />
</navigation>
I want to achieve this navigation pattern:
StartFragment => NestedStartFragment => NestedSecondFragment =(back)=> StartFragment
I'm trying to implement this by setting the action NestedStartFragment=>NestedSecondFragment with the options [popUpTo=NestedStartFragment, popUpToInclusive=true], so that the resulting stack would be:
0. NestedSecondFragment
1. NestedNavGraph
2. StartFragment
3. NavGraph
When navigating from NestedStartFragment to NestedSecondFragment, the following execption occurs:
java.lang.IllegalArgumentException: Navigator androidx.navigation.fragment.FragmentNavigator@ccc9092 reported navigation to unknown destination id com.example.navbug:id/nestedSecondFragment
at androidx.navigation.NavController$2.onNavigatorNavigated(NavController.java:142)
at androidx.navigation.Navigator.dispatchOnNavigatorNavigated(Navigator.java:217)
at androidx.navigation.fragment.FragmentNavigator.navigate(FragmentNavigator.java:207)
at androidx.navigation.fragment.FragmentNavigator.navigate(FragmentNavigator.java:45)
at androidx.navigation.NavDestination.navigate(NavDestination.java:407)
at androidx.navigation.NavController.navigate(NavController.java:683)
at androidx.navigation.NavController.navigate(NavController.java:630)
at androidx.navigation.NavController.navigate(NavController.java:618)
at com.example.navbug.NestedStartFragment$onViewCreated$1.onClick(Fragments.kt:31)
at android.view.View.performClick(View.java:6597)
at android.view.View.performClickInternal(View.java:6574)
at android.view.View.access$3100(View.java:778)
at android.view.View$PerformClick.run(View.java:25885)
at android.os.Handler.handleCallback(Handler.java:873)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
Right before the navigation, the stack is:
0. NestedStartFragment
1. NestedNavGraph
2. StartFragment
3. NavGraph
When NestedStartFragment is popped on my request, NestedNavGraph is also popped because
"// We never want to leave NavGraphs on the top of the stack" (from NavController.onNavigatorNavigated)
with the effect that eventually the requested destination NestedSecondFragment is pruned from the graph and cannot be reached anymore.
Unless I'm doing something wrong, it seems that NavGraph automatic popping should be avoided if the final destination actually belongs to it.