Dagger Hilt: cannot be provided without an @Provides-annotated method

Question

When I use interface like below in viewmodel

class MainViewModel @ViewModelInject constructor(
    private val trafficImagesRepository: TrafficImageRepository, <----------------- Not working
    @Assisted private val savedStateHandle: SavedStateHandle
) : ViewModel()

I am getting an error like below

cannot be provided without an @Provides-annotated method.
  public abstract static class SingletonC implements MainApplication_GeneratedInjector,

My interface is like below

interface TrafficImageRepository {
    suspend fun getTrafficImages() : NetworkResponse<TrafficData, ErrorTrafficImages>
}

And Repository class is like below

class DefaultTrafficImagesRepository @Inject constructor(private val trafficImageService: TrafficImageService) : TrafficImageRepository {

    override suspend fun getTrafficImages(): NetworkResponse<TrafficData, ErrorTrafficImages> {
        lateinit var response: NetworkResponse<TrafficData, ErrorTrafficImages>
        withContext(IO) {
            val currentTimestamp = Constants.getCurrentTime()
            response = trafficImageService.getTrafficImages(currentTimestamp)
        }
        return response
    }
}

But when I use DefaultTrafficImagesRepository class directly instead of Interface my app is able to build without any error.

class MainViewModel @ViewModelInject constructor(
    private val trafficImagesRepository: DefaultTrafficImagesRepository , <----------------- Working Fine
    @Assisted private val savedStateHandle: SavedStateHandle
) : ViewModel()

Saeed Lotfi Saeed Lotfi · Accepted Answer · 2021-01-30T09:08:29

You must to bind interface

@Module
@InstallIn(ViewModelComponent::class)
abstract class RepositoryModule {

    @Binds
    abstract fun bindRepository(impl: DefaultTrafficImagesRepository): TrafficImageRepository 
}

and use viewmodel inject in this way

@HiltViewModel
class MainViewModel @Inject constructor(
    private val trafficImagesRepository: TrafficImageRepository,
    @Assisted private val savedStateHandle: SavedStateHandle
) : ViewModel()

Dagger Hilt: cannot be provided without an @Provides-annotated method

1 Answers