Is there any way to grab arguments inside a `viewModel` when using `navigation-compose` ?

# compose

[Nikola Drljaca]

Is there any way to grab arguments inside a viewModel when using navigation-compose ?

[Ian Lake]

The SavedStateHandle of a ViewModel will automatically be populated with the arguments of the destination

[Nikola Drljaca]

And that is true even though I'm using navigate-compose?

[Nikola Drljaca]

That question is redundant, sorry 😅

[Gabriel]

@Ian Lake are there any examples combining navigation and viewmodel as you've described?

[zoha131]

@Ian Lake is this something new that is being working on? that would be really awesome!

[Ian Lake]

This has been the case since Navigation 2.2.0, released over a year ago, which was the release that added support for SavedStateViewModelFactory (which is what gives you SavedStateHandle): https://developer.android.com/jetpack/androidx/releases/navigation#2.2.0

[Ian Lake]

There's nothing Navigation Compose specific about this, just another thing you get for free

[Ian Lake]

(the same thing happens with activities and fragments getting their extras/arguments when using SavedStateHandle there)

[zoha131]

correct me if I am wrong. If I require a String as the argument for the destination. then I will get the argument automatically inside SavedStateHandle even if I use compose.

[Ian Lake]

You are correct. That has indeed always been the case

[zoha131]

wow. thanks for this. I wish I knew it earlier.

[Gabriel]

@Ian Lake if we're scoping the viewmodel to a composable, what's the SavedStateRegistryOwner?

composable(Screen.LaunchScreen.route) {
            val playersViewModel = viewModel<PlayersViewModel>(
                factory = PlayersViewModelFactory(
                    this,<--- what should this be?
                    PlayersRepository()
                )
            )
            LaunchScreen(playersViewModel)
        }

[Gabriel]

Or do we need to it in the activity for this to work?

[Ian Lake]

it - the NavBackStackEntry is a SavedStateRegistryOwner

[Gabriel]

🤦

[Gabriel]

of course it is