Dagger with Kotlin in Android: lateinit property viewModelProviderFactory has not been initialized

Question

My code:

1. App Component:

@Component(
    modules = [
        AndroidSupportInjectionModule::class,
        ActivityBuildersModule::class,
        ViewModelFactoryModule::class
    ]
)
interface AppComponent : AndroidInjector<BaseApplication> {

    @Component.Builder
    interface Builder {

        @BindsInstance
        fun application(application: Application): Builder

        fun build(): AppComponent
    }
}

2. ActivityBuildersModule:

@Module
abstract class ActivityBuildersModule {

    @ContributesAndroidInjector(
        modules = [MainActivityViewModelModule::class]
    )
    abstract fun contributeMainActivity(): MainActivity
}

3. MainActivityViewModelModule:

@Module
abstract class MainActivityViewModelModule {

    @Binds
    @IntoMap
    @ViewModelKey(MainActivityViewModel::class)
    public abstract fun bindMainActivityViewModel(mainActivityViewModel: MainActivityViewModel): ViewModel
}

4. MainActivityViewModel:

class MainActivityViewModel @Inject constructor(application: Application) : AndroidViewModel(application) {
   // empty for now
}

5. ViewModelKey (in Java):

@Documented
@Target({ElementType.METHOD})
@Retention(RetentionPolicy.RUNTIME)
@MapKey
public @interface ViewModelKey {

    Class<? extends ViewModel> value();
}

6. MainActivity:

class MainActivity : AppCompatActivity() { <-- I made mistake here. I must Extend DaggerAppCompatActivity instead of AppCompatActivity.

//  doesn't work for now
    @Inject
    lateinit var viewModelProviderFactory: ViewModelProviderFactory

    lateinit var mainActivityViewModel: MainActivityViewModel

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        setContentView(R.layout.activity_main)

        mainActivityViewModel = ViewModelProvider(this, viewModelProviderFactory).get(MainActivityViewModel::class.java)

        setMainFragment()
    }

    private fun setMainFragment() {
        // my code
    }
}

It gives me an error: lateinit property viewModelProviderFactory has not been initialized.

The same code works fine in another project in Java.

Answer 1

Extend DaggerAppCompatActivity instead of AppCompatActivity