Does the automatic saved state population of navigation arguments only work with HiltViewModel or is...

# compose

[André Thiele]

Does the automatic saved state population of navigation arguments only work with HiltViewModel or is it also populated when using Koin for instance? Or do I need to use hiltNavGraphViewModel? (as shown here:

https://youtu.be/0z_dwBGQQWQ?t=968▾

)

[Vipulyaara]

SavedStateViewModelFactory is the default factory used when using by viewModel()
You can use it without Hilt

https://developer.android.com/jetpack/androidx/releases/navigation#2.2.0

[André Thiele]

Ah thanks! Exactly what I was looking for. It says "when using by navGraphViewModels()"

[André Thiele]

will try this out

[Vipulyaara]

That’s in the non-compose world I think. Compose uses by viewModel()

[Vipulyaara]

But it should work the same way

[André Thiele]

Ah true, thanks for the info

[André Thiele]

mhm, does not really work

[André Thiele]

java.lang.ClassCastException: java.lang.Object cannot be cast to androidx.lifecycle.ViewModel
at androidx.lifecycle.ViewModelProvider$NewInstanceFactory.create(ViewModelProvider.java:219)
at androidx.lifecycle.ViewModelProvider$AndroidViewModelFactory.create(ViewModelProvider.java:278)
at androidx.lifecycle.SavedStateViewModelFactory.create(SavedStateViewModelFactory.java:112)

[André Thiele]

when using by viewModel()

[André Thiele]

org.koin.core.error.InstanceCreationException: Could not create instance for [Factory:'app.project.chat.ui.screens.chat.ChatViewModel']
at org.koin.core.instance.InstanceFactory.create(InstanceFactory.kt:61)
at org.koin.core.instance.FactoryInstanceFactory.get(FactoryInstanceFactory.kt:36)
at org.koin.core.registry.InstanceRegistry.resolveInstance$koin_core(InstanceRegistry.kt:103)

[André Thiele]

when using = get() in parameter

[André Thiele]

sooo the normal way does not work for me: java.lang.ClassCastException: java.lang.Object cannot be cast to androidx.lifecycle.ViewModel

[André Thiele]

getStateViewModel actually works but the id is not passed in

[Slava Glushenkov]

I'd have a problem with new viewmodel instance creatIon instead of return existing one when use Compose Navigation. Same with Hilt as with Koin.

[André Thiele]

what do you mean?

[Ian Lake]

That stack trace indicates that you are using the default factory and not a factory that knows anything about Koin. Have you looked at the Koin docs? https://insert-koin.io/docs/reference/koin-android/compose/#viewmodel-for-composable