How to use pass the activity to an dagger module using the new `dagger-android`

Question

Android Studio 3.4
dagger-android 2.21

How to use pass the activity to an dagger module using the new dagger-android

Before using the older version of dagger we could pass the Activity in the constructor and return that in the provider method. But I not sure how to do that with dagger-android

I have the following module. However, dagger doesn't now about the ForecastActivity .

@Module
class ActivityModule {
    @Reusable
    @Provides
    fun provideRetryListener(forecastActivity: ForecastActivity): RetryListener {
        return forecastActivity
    }
}

The RetryListener is a interface that the ForecastActivity implements. I want to be able to inject this RetryListener into my RetryFragment ie

class RetryFragment : Fragment() {
    @Inject
    lateinit var retryListener: RetryListener // Inject here

    override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View? {
        AndroidSupportInjection.inject(this)

    super.onCreateView(inflater, container, savedInstanceState)

    retryListener.onRetry() // usage like this
        return inflater.inflate(R.layout.failurecase_layout, container, false)
    }
}

In the forecastActivity

class ForecastActivity : AppCompatActivity(), RetryListener {

    @Inject
    lateinit var forecastPresenter: ForecastPresenter

    override fun onCreate(savedInstanceState: Bundle?) {
        AndroidInjection.inject(this)
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_home)
    }

    override fun onRetry() {
       /* do something here */
    }
}

My ActivityBuilder is the following:

@Module
abstract class ActivityBuilder {
    @ContributesAndroidInjector(modules = [ActivityModule::class])
    abstract fun injectIntoRetryFragment(): RetryFragment
}

My component is this:

@Singleton
@Component(modules = [
    AndroidSupportInjectionModule::class,
    ActivityBuilder::class,
    ActivityModule::class])
interface StockComponent {
    @Component.Builder
    interface Builder {
        @BindsInstance
        fun application(application: StockApplication): Builder

        fun build(): StockComponent
    }

    fun inject(application: StockApplication)
}

And my Application is:

class StockApplication : Application(), HasActivityInjector, HasSupportFragmentInjector {

    @Inject
    lateinit var dispatchingAndroidActivityInjector: DispatchingAndroidInjector<Activity>

    @Inject
    lateinit var dispatchingAndroidFragmentInjector: DispatchingAndroidInjector<Fragment>

    override fun onCreate() {
        super.onCreate()

        DaggerStockComponent
            .builder()
            .application(this)
            .build()
            .inject(this)
    }

    override fun activityInjector(): AndroidInjector<Activity> {
        return dispatchingAndroidActivityInjector
    }

    override fun supportFragmentInjector(): AndroidInjector<Fragment> {
        return dispatchingAndroidFragmentInjector
    }
}

So the question is when using dagger-android how can I inject the RetryListener into the RetryFragment that the RetryListener is implemented by the ForecastActivity ?

Many thanks in advance

Answer 1

I can't see a module that provides your ForecastActivity , ie:

@ContributesAndroidInjector
abstract fun forecastActivity(): ForecastActivity

The Activity will need to implement HasSupportFragmentInjector , and supply a DispatchingAndroidInjector<Fragment>