Singleton component cannot depend on scoped components

Question

While working on Android application using Dagger2 for dependency injects while defining Dagger component I'm getting this error

Error:(13, 1) error: This @Singleton component cannot depend on scoped components:
@Singleton com.eaxample.app.DaggerAndroid.networkhandler.WebserviceComponent

My code of component is here:

@Singleton
@Component(modules = {WebserviceModule.class}, dependencies = {ApplicationComponent.class})
public interface WebserviceComponent {
      WebserviceHelper providesWebserviceHelper();
}

Code of componeent in which I'm getting error is:

@Singleton
@Component(modules = {RemoteDataModule.class}, dependencies = {WebserviceComponent.class})
public interface RemoteDataSourceComponent {
       RemoteDataSource providesRemoteDataSource();
}

Why am I getting this error and how to resolve this?

Answer 1

While dmitriyzaitsev's answer explains why you get the error, here's how you can solve it:

1. Define your own scope (it will actually also behave like a Singleton scope). E.g. a file called RemoteDataScope.java:

   @Scope
   @Retention(RetentionPolicy.RUNTIME)
   public @interface RemoteDataScope {
   }
   

2. Use the new scope, e.g. @RemoteDataScope instead of @Singleton in your RemoteDataSourceComponent:

   @RemoteDataScope
   @Component(modules = {RemoteDataModule.class}, dependencies = {WebserviceComponent.class})
   public interface RemoteDataSourceComponent {
          RemoteDataSource providesRemoteDataSource();
   }