Dagger02: Inject Activities with @ContributesAndroidInjector

• Components acts as Services.

• Activities/Fragments acts as Clients.

• Dagger Module: They are a place for dependencies to live so that we can add them to the components.

1. Create a ActivityBuildersModule class. This is the class where the DI of the Activity we want would happen. In this case it is AuthActivity.

import dagger.Module;

import dagger.android.ContributesAndroidInjector;

@Module

public abstract class ActivityBuildersModule {

    @ContributesAndroidInjector

    abstract AuthActivity contributeAuthActivity();

}

2. Add this module into the AppComponent class module section.

@Component(

        modules = {

                AndroidSupportInjectionModule.class,

                ActivityBuildersModule.class

        }

)

Now we can basically inject stuff into the AuthActivity.

3. Change the Activity to extend from DaggerCompatActivity.