Hilt and AssistedInject working together in Hilt v2.28-alpha times - ViewModel version

AnAndroidApp.kt

// AssistedInject and Hilt working together in v2.28-alpha times
// Example of a ViewModel using AssistedInject injected in a Fragment by Hilt
// As AssistedInject isn't part of Dagger yet, we cannot use in
// conjuction with @ViewModelInject

data class MyInitParams(private val neededId: String)

class MyViewModel @AssistedInject constructor(
  ... // Other dependencies injected by Hilt
  // com.squareup.inject.assisted.Assisted annotation
  @Assisted private val initParams: MyInitParams
) : ViewModel() {
  ... // ViewModel logic

  @AssistedInject.Factory
  interface AssistedFactory {
    fun create(initParams: MyInitParams): MyViewModel
  }

  companion object {
    fun provideFactory(
        assistedFactory: AssistedFactory,
        initParams: MyInitParams
    ): ViewModelProvider.Factory = object : ViewModelProvider.Factory {
         override fun <T : ViewModel?> create(modelClass: Class<T>): T {
           return assistedFactory.create(initParams) as T
         }
    }
  }
}


// This code uses "com.squareup.inject:assisted-inject-annotations-dagger2:0.5.2"
// AssistedInject puts all assisted bindings in the same module.
// We need to make a decision about where to install it. 
// In this case, as we only need it in fragments, we install it there.
@InstallIn(FragmentComponent::class)
@AssistedModule
@Module(includes = [AssistedInject_AssistedInjectModule::class])
// Needed until AssistedInject is incorporated into Dagger
interface AssistedInjectModule {}


@AndroidEntryPoint // Fragment injected by Hilt
class MyFragment : Fragment() {

  private val args: MyFragmentArgs by navArgs()
  
  // Inject the factory generated by AssistedInject
  @Inject lateinit var myViewModelAssistedFactory: MyViewModel.AssistedFactory

  // Initialize the ViewModel using ViewModelProvider.Factory 
  private val myViewModel: MyViewModel by viewModels {
    MyViewModel.provideFactory(
      myViewModelAssistedFactory, MyInitParams(args.neededId)
    )
  }
  
  ... // Fragment logic
}


// To disable checking for the InstallIn annotation in some modules,
// you need to enable the compiler option in your build.gradle file like this:
android {
    defaultConfig {
        javaCompileOptions {
            annotationProcessorOptions {
                arguments["dagger.hilt.disableModulesHaveInstallInCheck"] = "true"
            }
        }
    }
}