Status Update
Comments
ap...@google.com <ap...@google.com> #2
Oh I forgot to mention that I thought it might be connected to this issue:
jb...@google.com <jb...@google.com> #3
Please provide a minimal sample project along with the minimal steps to recreate the issue in the project.
pr...@google.com <pr...@google.com> #4
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:
Description
Once Fragments are driven by Lifecycle ( https://issuetracker.google.com/127528777 ), the NavController will not yet be available an
Activity
'sonCreate()
function.We should make the
navController
property inNavHostFragment
lazy and make sure it is unconditionally created it in theNavHostFragment
’sonCreate()
or created early when called.