i have dagger already set up with two components. One component is a subcomponent of another, big deal. Everything works. But then i randomly wanted to try constructor injection so i created a random class and marked its constructor with the Inject annotation and to my surprise when i wnated to inject this class it works ? my Component(s) know nothing about this. I have no written in my components interface about this class. its just a random class that has a constructor annotated with @Inject. How is this working ? Here is the random class:
public class Knife {
@Inject
public Knife(){
System.out.println("a spreading knife has been created");
};
}
and here is how call inject my class if that matters:
public class MainActivity extends AppCompatActivity {
private final String TAG = getClass().getSimpleName();
//@Inject
//AlmondButter someAlmondButter;
@Inject
CashewSandwich sandwich;
@Inject
CashewSandwich sandwich2;
/*some how this is getting injected but its not in any component, how ?No ones
providing it in a module either*/
@Inject
Knife mKnife;
SandwichComponent sandwichComponent;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
/*create the dependent butter for the sandwich here*/
ButterComponent butterComponent=DaggerButterComponent.builder().
butterModule(new ButterModule()).build();
/*create a scope sandwichcomponent here */
sandwichComponent=DaggerSandwichComponent.builder().sandwichModule(new SandwichModule()).
butterComponent(butterComponent)
.build();
//finally we have a sandwichComponent, lets inject our dependencies
sandwichComponent.inject(this);
Log.v(TAG," first:"+sandwich.toString());
Log.v(TAG,"second:"+sandwich2.toString());
Log.v(TAG,mKnife.toString()); //this actually works !
}
}
UPDATE: I wrote a blog on this feature incase anyone needs help: http://j2emanue.blogspot.ca/
