Agfdhyk

I'm trying to figure out why I am unable to install a module into my fragment subcomponent via @ContributesAndroidInjector. For instance:

The following works (compiles and is properly injected),

@Module(includes = ColumnWidthModule.class)  

public abstract class GalleryFragmentModule

{

    @ContributesAndroidInjector

    abstract GalleryFragment bindGalleryFragment();

}

but the following does not compile:

@Module  

public abstract class GalleryFragmentModule

{

    @ContributesAndroidInjector(modules = ColumnWidthModule.class)

    abstract GalleryFragment bindGalleryFragment();

}

The compiler error I'm getting is this:

AppComponent.java:24: error: [Dagger/MissingBinding] @javax.inject.Named("columnWidth") java.lang.Integer cannot be provided 

without an @Provides-annotated method.



UPDATE: Here is the full error:



error: [Dagger/MissingBinding] @javax.inject.Named("columnWidth") java.lang.Integer cannot be provided without an @Provides-annotated method.

public interface AppComponent

   ^

A binding with matching key exists in component: GalleryFragmentModule_BindGalleryFragment.GalleryFragmentSubcomponent

  @javax.inject.Named("columnWidth") java.lang.Integer is injected at

      GalleryFragment.columnWidth

  javax.inject.Provider<GalleryFragment> is injected at

      GalleryActivity.galleryFragmentProvider GalleryActivity is injected at

      dagger.android.AndroidInjector.inject(T) [AppComponent → ActivityBindingModule_BindGalleryActivity.GalleryActivitySubcomponent]

  It is also requested at: GalleryFragment.AutoFitGridLayoutManager(…, columnWidth)

  The following other entry points also depend on it:

  dagger.android.AndroidInjector.inject(T) [AppComponent → ActivityBindingModule_BindGalleryActivity.GalleryActivitySubcomponent → GalleryFragmentModule_BindGalleryFragment.GalleryFragmentSubcomponent]

1 error

The module itself looks like this:

@Module

public class ColumnWidthModule

{

    @Provides

    @Named("columnWidth")

    static int columnWidth()

    {

        return 300;

    }

}

and here is where I inject the variable:

public class GalleryFragment extends Fragment

{

    @Inject

    @Named("columnWidth")

    int columnWidth;



    @Override

    public void onAttach(Context context)

    {

        AndroidSupportInjection.inject(this); 

        super.onAttach(context);

    }



    // rest of code not shown 

}

Any help would be appreciated.

I was able to fix this one of two ways:

1. 
   

   I noticed that my activity injects a provider for my fragment, like so:

   
   
   

   public class GalleryActivity extends AppCompatActivity implements HasSupportFragmentInjector
   
   {
   
       @Inject
   
       DispatchingAndroidInjector<Fragment> fragmentInjector;
   
   
   
       @Inject
   
       Provider<GalleryFragment> galleryFragmentProvider;
   
   
   
       @Override
   
       protected void onCreate(Bundle savedInstanceState)
   
       {
   
           AndroidInjection.inject(this);
   
           // ...
   
   
   
           getSupportFragmentManager()
   
               .beginTransaction()        
   
               .add(R.id.fragment_container, galleryFragmentProvider.get(), null)
   
               .commit();
   
   
   
       }
   
   }
   
   

   
   
   

   The GalleryActivity has a Provider<GalleryFragment>, which means that it is also dependent on columnWidth. In other words, columnWidth is a dependency of GalleryFragment, and GalleryFragment in turn is a dependency of GalleryActivity. Removing the galleryFragmentProvider and changing the fragment transaction to just use a new GalleryFragment() will fix this:

   
   
   

       getSupportFragmentManager().beginTransaction()
   
           .add(R.id.fragment_container, new GalleryFragment(), null).commit();
   
   

   
   

2. 
   

   Another way to fix this and continue using the Provider<GalleryFragment> in the activity is to install the ColumnWidthModule to the activity's contributesAndroidInjector instead, namely this:

   
   
   

   public abstract class ActivityBindingModule
   
   {
   
       @ActivityScope
   
       @ContributesAndroidInjector(modules = { 
   
           GalleryFragmentModule.class, 
   
           ColumnWidthModule.class })
   
       abstract GalleryActivity bindGalleryActivity();
   
   }
   
   

   
   
   

   I guess the reason why it worked is because it's pretty much equivalent to what I posted above:

   
   
   

   @Module(includes = ColumnWidthModule.class)  
   
   public abstract class GalleryFragmentModule
   
   {
   
       @ContributesAndroidInjector
   
       abstract GalleryFragment bindGalleryFragment();
   
   }