Access deep-link parameters from an Android View Model's injected SavedStateHandle

Question

How would I access data from a deep-link inside of an Android's Architecture Components ViewModel at its init-time. I have access to extras provided in the intent's Bundle (intent.extras) through a Hilt-injected SavedStateHandle, but when opening the Activity through a deep-link, I only have a URI (intent.data) on the Activity level, and nothing in the ViewModel.

As an example, say I'm opening my activity through something like my-app://profile?id=123, how would I get access to that 123 ID from an AAC ViewModel at init-time?

Answer 1

One solution to this could be to intercept the creation of the view model. The ComponentActivity.viewModels() extension allows changing the CreationExtras, which will get passed to the SavedStateHandle:

public inline fun <reified VM : ViewModel> ComponentActivity.viewModels(
    noinline extrasProducer: (() -> CreationExtras)? = null,
    noinline factoryProducer: (() -> Factory)? = null
): Lazy<VM>

By default, a ComponentActivity creates extras for its view models through getDefaultViewModelCreationExtras(), which only grabs extras from the intent, but passing a extrasProducer, we can inject more things:

private val viewModel: SomeViewModel by viewModels(
    extrasProducer = {
        val extras = MutableCreationExtras(defaultViewModelCreationExtras)

        intent?.data?.getQueryParameter("id")?.let { queryParamId ->
            extras[DEFAULT_ARGS_KEY] = bundleOf("id" to queryParamId)
        }

        extras
    }
)