How to add DI (Dagger 2) in Activity and its parent

Question

I use Dagger 2 in my android project and want to use the @Inject in an Activity and inside another Activity which extends the first one -> MainActivity extends NetworkBaseActivity. In both Activities inside the onCreate() methods I have this:

AndroidInjection.inject(this);

Also, I have the next structure:

@Singleton
@Component(modules = {
    AndroidInjectionModule.class,
    AppModule.class,
    ActivityBuilderModule.class,
    WebServiceModule.class})
public interface AppComponent {

    @Component.Builder
    interface Builder {

        @BindsInstance
        Builder application(Application application);

        AppComponent build();
    }

    void inject(App app);

}

@Module
public abstract class ActivityBuilderModule {

    @ContributesAndroidInjector(modules = {NetworkActivityModule.class})
    public abstract NetworkBaseActivity bindNetworkBaseActivity();

    @ContributesAndroidInjector(modules = {MainActivityModule.class})
    public abstract MainActivity bindMainActivity();    
}

@Module
public class NetworkActivityModule {

    @Provides
    public NetworkViewModelFactory 
    provideNetworkViewModelFactory(AuthRepository authRepository) {
    return new NetworkViewModelFactory(authRepository);
    }

    @Provides
    public AuthRepository provideAuthRepository(WebServiceApi webServiceApi, 
    SharedPreferencesManager sharedPreferencesManager) {
        return new AuthRepository(webServiceApi, sharedPreferencesManager);
    }
}

@Module
public class MainActivityModule {

}

And in the onCreate() callback of my Application class I have this:

DaggerAppComponent
            .builder()
            .application(this)
            .build()
            .inject(this);

But receive this error:

error: [Dagger/MissingBinding] [dagger.android.AndroidInjector.inject(T)] 
com.example.android.view.base.NetworkViewModelFactory cannot be provided 
without an @Inject constructor or an @Provides-annotated method.
A binding with matching key exists in component:  
com.example.android.data.di.ActivityBuilderModule_BindNetworkBaseActivity
.NetworkBaseActivitySubcomponent
com.example.android.view.base.NetworkViewModelFactory is injected at
com.example.android.view.base.NetworkBaseActivity.mViewModelFactory
com.example.android.view.main.MainActivity is injected at
dagger.android.AndroidInjector.inject(T)
component path: com.example.android.data.di.AppComponent ?  
com.example.android.data.di.ActivityBuilderModule_BindMainActivity
.MainActivitySubcomponent

Any suggestions? :)

Answer 1

As MainActivity extends from NetworkBaseActivity you just need an AndroidInjector for the MainActivity. NetworkBaseActivity will then be injected through MainActivity.

@Module
public class NetworkActivityModule {
    @ContributesAndroidInjector(modules = { NetworkActivityModule.class })
    public abstract MainActivity bindMainActivity();    

}