Allow Fragments to depend on Activity Subcomponents when using ContributesAndroidInjector

Consider the below example:

@Module
abstract class BuildersModule {
    @ActivityScope
    @ContributesAndroidInjector(modules = ModuleA.class)
    abstract ActivityA contributeActivity();

    @ActivityScope
    @ContributesAndroidInjector
    abstract FragmentA contributeFragmentA();

    @ActivityScope
    @ContributesAndroidInjector(modules = ModuleB.class)
    abstract FragmentB contributeFragmentB();
}

The two Fragments are children of ActivityA. We don’t have an easy means of sharing Activity-scoped bindings between the Activity and the Fragments because all the generated subcomponents hang off ApplicationComponent.

It would be great if we could : 1) share ActivityA’s component with FragmentA 2) Specify FragmentB’s component as a Subcomponent of ActivityA’s component.

[PhilGlass]

@Module abstract class FragmentsModule {
    @ContributesAndroidInjector
    abstract FragmentA contributeFragmentA();

    @ContributesAndroidInjector(modules = ModuleB.class)
    abstract FragmentB contributeFragmentB();
}

@Module abstract class ActivityModule {
    @ContributesAndroidInjector(modules = ModuleA.class, FragmentsModule.class)
    abstract ActivityA contributeActivityA();
}

If you structure your modules like this (with ActivityModule installed in your ApplicationComponent), the generated fragment injectors will be subcomponents of your activity component & will have access to bindings declared in ModuleA.

[josh-burton]

Does the above approach still work? I’ve tried to implement it and dagger complains that it can’t find an android injector for the fragments.

Are there any extra steps needed to get this to work?

Edit: I’ve found the issue - my activities weren’t extending from DaggerActivity (I was calling AndroidInjection.inject manually).