Hi everyone, I just hit a roadblock using SafeArgs...

# android

[Tiago Nunes]

Hi everyone, I just hit a roadblock using SafeArgs + Hilt + LiveData + ViewModel... my use case is:

• ParentFragment is a fragment within a Navigation Graph, which has a SharedViewModel with some LiveData, and hosts a ViewPager2
• ChildAFragment is a fragment inserted into the ViewPager, which shows and changes some SharedViewModel's LiveData
• ChildBFragment is another fragment inserted into the ViewPager, which shows and changes some SharedViewModel's LiveData
So far so good, now the problem is: ParentFragment receives an argument. This argument should be in the ViewModel.

Usually I would do:

@HiltViewModel
class SomeViewModel @Inject constructor(
    savedStateHandle: SavedStateHandle,
): ViewModel() {

    val argument: Argument =
        savedStateHandle[ParentFragmentArgs::argument.name]!!
}

However, this does not work with SharedViewModel (

private val viewModel: SomeSharedViewModel by activityViewModels()

)

I think I understand why. This ViewModel isn't scoped to the Fragment, but to the Activity, so it probably gets the savedState of the Activity instead of the Fragment's (right?)

[Ian Lake]

Is there a reason you're scoping your ViewModel to your activity instead of to your parent fragment?

private val viewModel: SomeSharedViewModel by viewModels({ requireParentFragment() })

[Tiago Nunes]

Wow that was simple 😂 thanks so much 🙌