I am having a problem that I need inject an instance of repository class into Application class which is provided by Module (Installed in ViewModelComponent, and provide function marked with @ViewModelScope annotation)

Repository

interface IARepository

class ARepository @Inject constructor() : IARepository

Module

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

    @Binds
    @ViewModelScoped
    fun provideARepos(impl: ARepository): IARepository
}

ViewModel

@HiltViewModel
class TestViewModel @Inject constructor(
    private val useCase1: UseCase1,
    private val useCase2: UseCase2,
) {
   ...
}

Two UseCase1 and UseCase2 are using IARepository, since if I provides IARepository with ViewModelScope, two instance useCase1 and useCase2 will be using the same instance of repository.

It worked until I inject repository into Application (singleton things)

Application

@HiltAndroidApp
class TestApplication : Application() {

    @Inject
    lateinit var a: IARepository
}

After that I got error

[Dagger/MissingBinding] IARepository cannot be provided without an @Provides-annotated method.
  public abstract static class SingletonC implements FragmentGetContextFix.FragmentGetContextFixEntryPoint

Application_HiltComponents.java:129: error: [Dagger/MissingBinding] ...core.domain.IARepository cannot be provided without an @Provides-annotated method.
  public abstract static class SingletonC implements FragmentGetContextFix.FragmentGetContextFixEntryPoint,
                         ^
  A binding for ....core.domain.IARepository exists in ...Application_HiltComponents.ViewModelC:
      ....core.domain.IARepository is injected at
          [...Application_HiltComponents.SingletonC] ...Application.a
      ...Application is injected at
          ...Application_HiltComponents.SingletonC] ...Application_GeneratedInjector.injectMoonRoverApplication

In application, I tried switch to inject directly implementation class is ARepository, it worked fine.

@HiltAndroidApp
class TestApplication : Application() {

    @Inject
    lateinit var a: ARepository
}

But I still want to use interface. Are there any solution for it?

CodePudding user response：

I think you have to use @Provides in module as below

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

    @Binds
    @ViewModelScoped
    @Provides
    fun provideARepos(impl: ARepository): IARepository
}

Also add @HiltViewModel in your view model as below

@HiltViewModel 
class TestViewModel @Inject constructor(
private val useCase1: UseCase1, private val useCase2: UseCase2
) {
       ...
    }

I hope it will help you.

CodePudding user response：

in viewmodel please specify the @HiltViewModel

@HiltViewModel 
class TestViewModel @Inject constructor(
private val useCase1: UseCase1, private val useCase2: UseCase2
) {
       ...
    }

edited:-

    @Module
    @InstallIn(SingletonComponent::class)
    object Module {
    @Provides
        fun ProvideImplRepo() = ImplRepo()
    }
    @Module
    @InstallIn(ViewModelComponent::class)
    abstract class RepositoryModule {
    
        @Binds
        abstract fun bindLoginRepository(impl: ImplRepo): Repo
}