How to inject ViewModel in the screen?

Hi

I was trying to use the library with the ViewModel with the screen. I usually inject the ViewModel into the screen via arguments as shown below.

SampleScreen

@Composable
@Destination(start = true)
fun SampleScreen(
    viewModel: SampleViewModel,
    navigator: DestinationsNavigator,
) {
         // components
}

When I try the same, I am getting a runtime error.

2022-01-14 03:37:55.843 6495-6495/com.example.project E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.project, PID: 6495
java.lang.RuntimeException: SampleViewModel was requested, but it is not present
    at com.example.project.destinations.SampleScreenDestination.Content(SampleScreenDestination.kt:34)
    at com.ramcosta.composedestinations.DefaultNavHostEngine.CallComposable(DefaultNavHostEngine.kt:144)
    at com.ramcosta.composedestinations.DefaultNavHostEngine.access$CallComposable(DefaultNavHostEngine.kt:30)
    at com.ramcosta.composedestinations.DefaultNavHostEngine$addComposable$1.invoke(DefaultNavHostEngine.kt:104)
    at com.ramcosta.composedestinations.DefaultNavHostEngine$addComposable$1.invoke(DefaultNavHostEngine.kt:103)

Could you please tell me if I missing some steps while setting up the library?

Navigation setup

@Composable
fun NavigationComponent(
    modifier: Modifier = Modifier
) {

    DestinationsNavHost(
        navGraph = NavGraphs.root,
        modifier = modifier
    )
}

How would you suggest injecting the VMs? How would you use the library with the Hilt library?

[raamcosta]

I’ll close the issue then, feel free to reopen it or add more comments if you want to 😃

[5AbhishekSaxena]

Cool, I’ll create a PR with the suggestions for the documentation.

Btw if people are not using Hilt, your solution might not be enough if you plan to access the navigation arguments from the SavedStateHandle.

A really good solution, thanks. I’ll update the same in my project.