Support fromSavedStateHandle in SafeArgs [136967621]

Fixed

Feature Request

androidx-bug-bounty

Status Update

No update yet.

Description

jo...@gmail.com

created issue #1

Jul 8, 2019 06:35PM

Components used:
androidx.navigation:navigation-safe-args-gradle-plugin:2.0.0
androidx.lifecycle:lifecycle-viewmodel-savedstate:1.0.0-alpha02

Allow SafeArgs to be created `fromSavedStateHandle` as one would from a bundle.

Comments

il...@google.com <il...@google.com> #2Jul 8, 2019 10:01PM

Yigit, do you have time to fix it?

reemission of the same liveData is racy

jo...@gmail.com <jo...@gmail.com> #3Jul 9, 2019 04:32PM

yea i'll take it.

ka...@gmail.com <ka...@gmail.com> #4Jul 7, 2020 07:00AM

Thanks for the detailed analysis. This may not be an issue anymore since we've started using Main.immediate there but I' not sure; I'll try to create a test case.

[Deleted User] <[Deleted User]> #5Jul 22, 2020 07:06PM

just emitting same live data reproduces the issue.

@Test
fun raceTest() {
val subLiveData = MutableLiveData(1)
val subject = liveData(testScope.coroutineContext) {
emitSource(subLiveData)
emitSource(subLiveData) //crashes
}
subject.addObserver().apply {
testScope.advanceUntilIdle()
}
}

g....@gmail.com <g....@gmail.com> #6Sep 27, 2020 08:21AM

With 2.2.0-alpha04 (that use Main.immediate), the issue seems to be still there (I tested it by calling emitSource() twice, like your test case)

ka...@gmail.com <ka...@gmail.com> #7Oct 11, 2020 09:49AM

yea sorry immediate does not fix it.
I actually have a WIP fix for it:

https://android-review.googlesource.com/c/platform/frameworks/support/+/1112186

if your case is the one i found (emitting same LiveData multiple times, as shown in #5) you can work around it by adding a dummy transformation.

val subLiveData = MutableLiveData(1)
val subject = liveData(testScope.coroutineContext) {
emitSource(subLiveData.map {it })
emitSource(subLiveData.map {it} )
}

g....@gmail.com <g....@gmail.com> #8Oct 11, 2020 11:38AM

Project: platform/frameworks/support
Branch: androidx-master-dev

commit af12e75e6b4110f48e44ca121466943909de8f06
Author: Yigit Boyar <yboyar@google.com>
Date: Tue Sep 03 12:58:11 2019

Fix coroutine livedata race condition

This CL fixes a bug in liveData builder where emitting same
LiveData source twice would make it crash because the second
emission registry could possibly happen before first one is
removed as source.

We fix it by using a suspending dispose function. It does feel
a bit hacky but we cannot make DisposableHandle.dispose async
and we do not want to block there. This does not mean that there
is a problem if developer disposes it manually since our emit
functions take care of making sure it disposes (and there is
no other way to add source to the underlying MediatorLiveData)

Bug: 140249349
Test: BuildLiveDataTest#raceTest_*

Change-Id: I0b464c242a583da4669af195cf2504e2adc4de40

M lifecycle/lifecycle-livedata-ktx/api/2.2.0-alpha05.txt
M lifecycle/lifecycle-livedata-ktx/api/current.txt
M lifecycle/lifecycle-livedata-ktx/api/public_plus_experimental_2.2.0-alpha05.txt
M lifecycle/lifecycle-livedata-ktx/api/public_plus_experimental_current.txt
M lifecycle/lifecycle-livedata-ktx/api/restricted_2.2.0-alpha05.txt
M lifecycle/lifecycle-livedata-ktx/api/restricted_current.txt
M lifecycle/lifecycle-livedata-ktx/src/main/java/androidx/lifecycle/CoroutineLiveData.kt
M lifecycle/lifecycle-livedata-ktx/src/test/java/androidx/lifecycle/BuildLiveDataTest.kt

https://android-review.googlesource.com/1112186

https://goto.google.com/android-sha1/af12e75e6b4110f48e44ca121466943909de8f06

al...@linguistica360.com <al...@linguistica360.com> #9Nov 12, 2020 11:39PM

If you are using hilt you can wrap the incoming arguments in fragment like so

open class BaseFragment : Fragment() {

    override fun setArguments(args: Bundle?) {
        if (args != null) {
            super.setArguments(Bundle(args).apply {
                putBundle(BUNDLE_ARGS, args) // Wrap the arguments as BUNDLE_ARGS
            })
        } else {
            super.setArguments(null)
        }
    }
}

and then for the view model, you can inherit from something like that

open class ArgsViewModel(private val savedStateHandle: SavedStateHandle) : ViewModel() {

    val arguments get() = savedStateHandle.get<Bundle>(BUNDLE_ARGS)

    @MainThread
    inline fun <reified Args : NavArgs> navArgs() = NavArgsLazy(Args::class) {
        arguments ?: throw IllegalStateException("ViewModel $this has null arguments")
    }
}

Hope that helps

si...@gmail.com <si...@gmail.com> #10Mar 2, 2021 07:28PM

Should be fixed by https://github.com/androidx/androidx/pull/122

il...@google.com <il...@google.com> Mar 2, 2021 08:08PM

Marked as fixed, reassigned to jb...@google.com.

al...@linguistica360.com <al...@linguistica360.com> #11Mar 3, 2021 10:24PM

Do you know when this will be released?

il...@google.com <il...@google.com> #12Mar 3, 2021 10:27PM

Re #11 - The public hotlist listed at the top of this bug says "androidx-navigation-2.4.0-alpha01" - that's the expected release.

ho...@gmail.com <ho...@gmail.com> #13May 31, 2021 10:31AM

It seems this has been included in the 2.4.0-alpha01 release.

But is there any additional setup required besides updating the navigation dependencies? With the following dependencies on my project

object Navigation {
    private const val version = "2.4.0-alpha01"
    const val compose = "androidx.navigation:navigation-compose:$version"
    const val fragment = "androidx.navigation:navigation-fragment-ktx:$version"
    const val safeArgsPlugin = "androidx.navigation:navigation-safe-args-gradle-plugin:$version"
    const val ui = "androidx.navigation:navigation-ui-ktx:$version"
}

my safeargs don't generate fromSavedStateHandle().

fromBundle() is still the only auto-complete suggestion.

FooFragmentArgs.fromSavedStateHandle(savedStateHandle) is an unresolved reference in my ViewModel.

ok...@gmail.com <ok...@gmail.com> #14Jun 1, 2021 11:38AM

I agree with the previous comment. FooFragmentArgs.fromSavedStateHandle(savedStateHandle) is unresolved reference in my ViewModel too. When I checked on generated FooFragmentArgs class, fromSavedStateHandle function is there but Android Studio can't find that reference. Code compiles successfully.

Android Studio : 4.2.1
com.android.tools.build:gradle:4.2.1
androidx.navigation:navigation-safe-args-gradle-plugin:2.4.0-alpha01

Is there any thing we can do about this?

il...@google.com <il...@google.com> #15Jun 1, 2021 05:02PM

Re #13, #14 - please upgrade to the latest version of Android Studio and file a bug against Android Studio if you are still not seeing this method in the Studio generated light classes.

ho...@gmail.com <ho...@gmail.com> #16Jun 3, 2021 09:07AM

I'm using Arctic Fox | 2020.3.1 Canary 9. I've just updated Navigation to 2.4.0-alpha02 and still seeing the bug, so I've filed a bug against AS. https://issuetracker.google.com/issues/189966590

ho...@gmail.com <ho...@gmail.com> #17Jun 4, 2021 07:15AM

As mentioned in the linked issue, manually downloading the latest version of Android Studio Preview fixes the issue