NavigationUI's onNavDestinationSelected() should log when it doesn't handle a MenuItem [247730357]

Fixed

Bug

Status Update

No update yet.

Description

sh...@gmail.com

created issue #1

Sep 20, 2022 09:55AM

Steps to reproduce the problem (including sample code if appropriate).
- Import enclosed TestBottomNav.zip to Android Studio and run
- Click Dashboard or Notification item on BottomNavigationView.
What happened.

There is no response after clicking tab item, meanwhile there is no related exception messages printed in Logcat.

This abnormal behaviour was intentional made on my part, just to amplify the problem. To fix it, go to app/src/main/res/menu/bottom_nav_menu.xml, change every android:id starts with Navigation to navigation will be fine.

What you think the correct behavior should be.

NavigationUI should not ate the exception message with a simple false return. This will drive novice developers crazy to find out the problem. See here and here. We should not design API from the perspective of "everyone knows why", and it is also inconsistent with Google's strong advocacy of Jetpack for novice developers over these years.

Is this a security related issue? Yes/No

No.

TestBottomNav.zip

346 KB

Download

Comments

sh...@gmail.com <sh...@gmail.com> #2Sep 20, 2022 10:49AM

Oh I forgot to mention that I thought it might be connected to this issue: https://issuetracker.google.com/issues/243778589. But after trying 2.5.2 I can say that the issue persists.

il...@google.com <il...@google.com> Oct 18, 2022 08:41PM

Assigned to jb...@google.com.

jb...@google.com <jb...@google.com> #3Oct 20, 2022 10:59PM

Reassigned to cl...@google.com.

Please provide a minimal sample project along with the minimal steps to recreate the issue in the project.

ap...@google.com <ap...@google.com> #4Nov 1, 2022 07:16PM

Sorry for the delay. I got a working example here: https://github.com/Del-S/issues. The project is set up to crash when navigating to ThirdFragment (nested nav graph) with poping the graph.

I poked into it a little bit and it seems to be connected to SafeArgs gradle plugin. When safe args is used to navigate to ThirdFragment (with nested graph poped) it will try to recreate te parent but there were no arguments passed so it crashes.

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: https://github.com/Del-S/issues/blob/master/app/src/main/java/cz/dels/issues/SecondFragment.kt#L37.

il...@google.com <il...@google.com> #5Nov 1, 2022 07:21PM

Marked as fixed.

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.

na...@google.com <na...@google.com> #6Nov 9, 2022 06:28PM

This has been fixed and will be available in navigation 2.6.0-alpha08

Issue 247730357