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da...@google.com
il...@google.com
So there does seem to be a bug in Navigation that causes this to fail.
When it navigates with popUpTo and removes SecondFragment, that removal in fragment is set for a frame later and before it is actually removed the navigate call in the onViewCreated of SecondFragment enqueues another call to add it back. But we still need to destroy SecondDetailFragment which ends up marking the NavBackStackEntry associated with SecondFragment as complete before navigation has received the call from the fragment that it has been added back. So by the time it hits this check, the SecondFragment is in the correct state, but Navigation has no way of referencing it so it assumes that it is not associated with an entry.
But this is not the way this type of situation should be implemented. Instead of having the destinations as part of the NavGraph, they should:
- be managed by the childFragmentManager of
SecondFragment. So instead of going back toSecondFragmentjust to go somewhere else, each of the fragments take the entire content ofSecondFragmentand are swapped out. - for some sort of a/b testing, set different graphs in the Activity. The graphs would keep the same
SecondFragmentid, but swap out the names and then you choose the correct graph based on the condition.
ma...@gmail.com
ap...@google.com
- Have
SecondFragmentas part of your graph and then inside ofSecondFragmentcall thechildFragmentManagerandreplacewith the fragment you actually want to show, whether that isSecondTypeOneorSecondTypeTwo. - Create different graphs and follow along with the
docs
il...@google.com
shardViewModel.onGetTypeSecond.observe(viewLifecycleOwner) { isType1 ->
if (isType1) {
val graph = findNavController().graph
val carInstallmentNavGraph =
graph.findNode(R.id.nav_second) as NavGraph
carInstallmentNavGraph.setStartDestination(R.id.secondTypeOneFragment)
findNavController().navigate(SecondFragmentDirections.actionSecondFragmentToSecondTypeOneFragment())
} else {
val graph = findNavController().graph
val carInstallmentNavGraph =
graph.findNode(R.id.nav_second) as NavGraph
carInstallmentNavGraph.setStartDestination(R.id.secondTypeTwoFragment)
findNavController().navigate(SecondFragmentDirections.actionSecondFragmentToSecondTypeTwoFragment())
}
}
and removed app:popUpTo="@id/secondFragment" and app:popUpToInclusive="true"
<fragment
android:id="@+id/secondFragment"
android:name="com.example.navigationdeeplink.SecondFragment"
android:label="fragment_second"
tools:layout="@layout/fragment_second" >
<action
android:id="@+id/action_secondFragment_to_secondTypeOneFragment"
app:destination="@id/secondTypeOneFragment" />
<action
android:id="@+id/action_secondFragment_to_secondTypeTwoFragment"
app:destination="@id/secondTypeTwoFragment"
app:popUpTo="@id/secondFragment" />
</fragment>
Description
Version used: 1.0.0-alpha06
After updating the safe-args plugin from alpha05 to alpha06, my build fails with the following stacktrace:
org.gradle.api.tasks.TaskExecutionException: Execution failed for task ':app:generateSafeArgsDebug'
Caused by: java.lang.IllegalStateException: Destination with actions must have name
at androidx.navigation.safe.args.generator.NavWriterKt.generateDirectionsJavaFile(NavWriter.kt:419)
at androidx.navigation.safe.args.generator.NavSafeArgsGeneratorKt$generateSafeArgs$1.invoke(NavSafeArgsGenerator.kt:43)
at androidx.navigation.safe.args.generator.NavSafeArgsGeneratorKt$generateSafeArgs$1.invoke(NavSafeArgsGenerator.kt:55)
at androidx.navigation.safe.args.generator.NavSafeArgsGeneratorKt.generateSafeArgs(NavSafeArgsGenerator.kt:58)
at androidx.navigation.safeargs.gradle.ArgumentsGenerationTask.generateArgs(ArgumentsGenerationTask.kt:54)
at androidx.navigation.safeargs.gradle.ArgumentsGenerationTask.doFullTaskAction(ArgumentsGenerationTask.kt:90)
at androidx.navigation.safeargs.gradle.ArgumentsGenerationTask.taskAction$navigation_safe_args_gradle_plugin(ArgumentsGenerationTask.kt:79)
Reverting to alpha05 makes the build complete.
I think this is related to the commit addressing this issue:
My navigation graph has this structure:
<navigation>
<fragment>
<action />
<argument />
</fragment>
<include app:graph="@navigation/nav_graph_two" />
...
<action />
</navigation>
That is, there are global actions, fragment destinations with arguments, fragment destinations with actions and an included nested graph (in a separate xml). Every single destination has a valid name and every root <navigation> has an id (everything works with version alpha05 of the plugin). I might guess this is related with global actions, which expect the parent destination to have a name that is not resolved with the alpha06 update. In fact, commenting out all the global actions makes the generateSafeArgsDebug task pass. My graphs have ids in the form "@+id/nav_graph_one".