Dagger2: no injector factory bound for fragment

Question

I\'m trying to convert a project that I\'m building to use the dagger-android API for the DI framework, but I\'m running into a dead end with an IllegalArgumentException whe

Answer 1

When you inject using AndroidSupportInjection.inject(this) from your HomeFragment, Dagger will walk the parent-fragment hierarchy to find someone that implements HasSupportFragmentInjector. To make it work, make your MainActivity extends DaggerAppCompatActivity which implements HasSupportFragmentInjector.

From the doc of AndroidSupportInjection.inject(Fragment fragment):

Injects {@code fragment} if an associated {@link dagger.android.AndroidInjector} implementation can be found, otherwise throws an {@link IllegalArgumentException}.

Uses the following algorithm to find the appropriate {@code AndroidInjector} to use to inject {@code fragment}:

1. Walks the parent-fragment hierarchy to find the a fragment that implements {@link HasSupportFragmentInjector}, and if none do
2. Uses the {@code fragment}'s {@link Fragment#getActivity() activity} if it implements {@link HasSupportFragmentInjector}, and if not
3. Uses the {@link android.app.Application} if it implements {@link HasSupportFragmentInjector}.

If none of them implement {@link HasSupportFragmentInjector}, a {@link IllegalArgumentException} is thrown.

@throws IllegalArgumentException if no parent fragment, activity, or application implements {@link HasSupportFragmentInjector}.

With this, Dagger will use

@FragmentScope
@ContributesAndroidInjector
abstract HomeFragment provideHomeFragment();

from your MainActivityModule to inject inside your HomeFragment.