Android Hilt - How to inject viewModelScope

Question

I want to inject viewModelscope but I just couldn't do it.

class PostPageSource @Inject constructor(
val repository: MyRepository,
val scope: CoroutineScope,
val mapper: MyMapper
) : PageKeyedDataSource<Int, Posts>() {

The error output is as follows:

[Dagger/MissingBinding] kotlinx.coroutines.CoroutineScope cannot be provided without an @Provides-annotated method.
public abstract static class ApplicationC implements App_GeneratedInjector,

I tried to:

@Module
@InstallIn(FragmentComponent::class)
object PagingModule {

@Singleton
@Provides
fun provideViewModel(fragment: Fragment) : UserDetailViewModel {
    val viewModel: UserDetailViewModel by (fragment as UserDetailFragment).viewModels()
    return viewModel
}

fun provideCorountineScope(fragment: UserDetailViewModel): CoroutineScope {
    return fragment.viewModelScope
}

}

The error output is as follows:

error: [Dagger/MissingBinding] kotlinx.coroutines.CoroutineScope cannot be provided without an @Provides-annotated method.
public abstract static class ApplicationC implements App_GeneratedInjector,
                     ^
  kotlinx.coroutines.CoroutineScope is injected at
      com.maksu.insider.userdetail.paging.PostPageSource(…, scope, …)
  javax.inject.Provider<com.maksu.insider.userdetail.paging.PostPageSource> is injected at
      com.maksu.insider.userdetail.paging.PostPageSourceFactory(providerDataSource)
  javax.inject.Provider<com.maksu.insider.userdetail.paging.PostPageSourceFactory> is injected at
      com.maksu.insider.userdetail.UserDetailViewModel_AssistedFactory(…, dataSourceFactory)
  com.maksu.insider.userdetail.UserDetailViewModel_AssistedFactory is injected at
      com.maksu.insider.userdetail.UserDetailViewModel_HiltModule.bind(factory)
  java.util.Map<java.lang.String,javax.inject.Provider<androidx.hilt.lifecycle.ViewModelAssistedFactory<? extends androidx.lifecycle.ViewModel>>> is injected at
      androidx.hilt.lifecycle.ViewModelFactoryModules.ActivityModule.provideFactory(…, viewModelFactories)
  @dagger.hilt.android.internal.lifecycle.DefaultActivityViewModelFactory java.util.Set<androidx.lifecycle.ViewModelProvider.Factory> is requested at
      dagger.hilt.android.internal.lifecycle.DefaultViewModelFactories.ActivityEntryPoint.getActivityViewModelFactory() [com.maksu.insider.App_HiltComponents.ApplicationC → com.maksu.insider.App_HiltComponents.ActivityRetainedC → com.maksu.insider.App_HiltComponents.ActivityC]

The following other entry points also depend on it:

Answer 1

I don't know why you want to do that, but I think you miss some @Provides at the top of your function:

@Provides
fun provideCorountineScope(fragment: UserDetailViewModel): CoroutineScope {
    return fragment.viewModelScope
}

But I really don't recommend doing this. If you want a coroutine that should last as long as the viewmodel does, then just launch the coroutine inside the viewmodel.