Dagger2 メモ

n 個の @Component から 1 個のインスタンスに inject

不可

public class Main {

  @Inject
  Red red;

  @Inject
  Blue blue;

  public Main() {
    DaggerBlueComponent.builder().blueModule(new BlueComponent.BlueModule()).build().inject(this);
    DaggerRedComponent.builder().redModule(new RedComponent.RedModule()).build().inject(this);
  }
}

public class Blue {
}

@BlueScope
@Component(modules = BlueComponent.BlueModule.class)
public interface BlueComponent {

  void inject(Main main);

  @Module
  class BlueModule {

    @BlueScope
    @Provides
    Blue provideBlue() {
      return new Blue();
    }
  }
}

@Scope
@Retention(RUNTIME)
public @interface BlueScope {
}

public class Red {
}

@RedScope
@Component(modules = RedComponent.RedModule.class)
public interface RedComponent {

  void inject(Main main);

  @Module
  class RedModule {

    @RedScope
    @Provides
    Red provideRed() {
      return new Red();
    }
  }
}

@Scope
@Retention(RUNTIME)
public @interface RedScope {
}

:sample:compileDebugJavaWithJavac
/Users/shogo/dev/code/android/myrepos/android-tasting-dagger2/sample/src/main/java/com/sho5nn/sample/di/BlueComponent.java:13: エラー: com.sho5nn.sample.di.Red cannot be provided without an @Inject consttor or from an @Provides- or @Produces-annotated method.
  void inject(Main main);
       ^
      com.sho5nn.sample.di.Red is injected at
          com.sho5nn.sample.Main.red
      com.sho5nn.sample.Main is injected at
          com.sho5nn.sample.di.BlueComponent.inject(main)
/Users/shogo/dev/code/android/myrepos/android-tasting-dagger2/sample/src/main/java/com/sho5nn/sample/di/RedComponent.java:13: エラー: com.sho5nn.sample.di.Blue cannot be provided without an @Inject consttor or from an @Provides- or @Produces-annotated method.
  void inject(Main main);
       ^
      com.sho5nn.sample.di.Blue is injected at
          com.sho5nn.sample.Main.blue
      com.sho5nn.sample.Main is injected at
          com.sho5nn.sample.di.RedComponent.inject(main)
エラー2個

@Scope ( @RedScope, @BlueScope ) を持っている/持っていないは関係ない

n 個の @Component に依存した 1 個の @Component から 1 個のインスタンスに inject

可能

public class Main {

  @Inject
  Red red;

  @Inject
  Blue blue;

  public Main() {
    BlueComponent blueComponent = DaggerBlueComponent.builder()
      .blueModule(new BlueComponent.BlueModule()).build();
    RedComponent redComponent = DaggerRedComponent.builder()
      .redModule(new RedComponent.RedModule()).build();

    DaggerColorComponent.builder()
      .blueComponent(blueComponent)
      .redComponent(redComponent)
      .build()
      .inject(this);
  }
}

@ColorScope
@Component(dependencies = {BlueComponent.class, RedComponent.class})
public interface ColorComponent {

  void inject(Main main);
}

@Scope
@Retention(RUNTIME)
public @interface ColorScope {
}

//@BlueScope
@Component(modules = BlueComponent.BlueModule.class)
public interface BlueComponent {

  Blue blue();

  @Module
  class BlueModule {

//    @BlueScope
    @Provides
    Blue provideBlue() {
      return new Blue();
    }
  }
}

//@RedScope
@Component(modules = RedComponent.RedModule.class)
public interface RedComponent {

  Red red();

  @Module
  class RedModule {

//    @RedScope
    @Provides
    Red provideRed() {
      return new Red();
    }
  }
}

依存先 @Component 全てが @Scope ( @RedScope, @BlueScope ) を持っていると不可

:sample:compileDebugJavaWithJavac
/Users/shogo/dev/code/android/myrepos/android-tasting-dagger2/sample/src/main/java/com/sho5nn/sample/Main.java:5: エラー: シンボルを見つけられません
import com.sho5nn.sample.data.DaggerBlueComponent;
                             ^
  シンボル:   クラス DaggerBlueComponent
  場所: パッケージ com.sho5nn.sample.data
/Users/shogo/dev/code/android/myrepos/android-tasting-dagger2/sample/src/main/java/com/sho5nn/sample/Main.java:6: エラー: シンボルを見つけられません
import com.sho5nn.sample.data.DaggerRedComponent;
                             ^
  シンボル:   クラス DaggerRedComponent
  場所: パッケージ com.sho5nn.sample.data
/Users/shogo/dev/code/android/myrepos/android-tasting-dagger2/sample/src/main/java/com/sho5nn/sample/Main.java:9: エラー: シンボルを見つけられません
import com.sho5nn.sample.domain.DaggerColorComponent;
                               ^
  シンボル:   クラス DaggerColorComponent
  場所: パッケージ com.sho5nn.sample.domain
/Users/shogo/dev/code/android/myrepos/android-tasting-dagger2/sample/src/main/java/com/sho5nn/sample/domain/ColorComponent.java:10: エラー: @com.sho5nn.sample.domain.ColorScope com.sho5nn.sample.domain.ColorComponent depends on more than one scoped component:
@Component(dependencies = {BlueComponent.class, RedComponent.class})
^
      @com.sho5nn.sample.data.BlueScope com.sho5nn.sample.data.BlueComponent
      @com.sho5nn.sample.data.RedScope com.sho5nn.sample.data.RedComponent
エラー4個

depends on more than one scoped component

---