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androidkotlindependency-injectiondagger-hilt

How to inject dependency in composable using dagger hilt

Maybe I'm blind but I can't find anything about injecting a dependency that needs parameters in side a composable using dagger hilt.

Lets say my ViewModel looks something like this:

class MyViewModel @AssistedInject constructor(@Assisted myValue: Int) : ViewModel() {
...
}

and I've got a factory interface like this:

@AssistedFactory
interface MyViewModelAssistedFactory {
    fun create(myValue: Int): MyViewModel
}

how can I inject that dependency with a certain value as parameter?

All answers I found where like:

@Inject
var myViewModelFactory: MyViewModelAssistedFactory;

and

val initValue = 4

fun onCreate(){
    val viewModel = myViewModelFactory.create(initValue)
}

but that doesn't work inside a composable fun.

Solution

  • Not sure if still relevant but if you use the navigation component you can just call hiltViewModel() in the navgraph builder. Example: https://github.com/pablichjenkov/ComposeStudy/blob/04298ca8393d3eea0f5b7883fb223161ef79a962/app/src/main/java/com/pablichj/study/compose/home/HomeNavigation.kt#L24

    If not using Jetpack Navigation then the solution is a bit more complex. You will need to create a State tree in your App where they implement LifecycleOwner and ViewModelStoreOwner, in order to be able to install the ViewModel appropriately. The good news is that there is work out there already doing so, check this: https://github.com/Syer10/voyager