Component which dependent from other components with different scopes (component hierarchies with different scopes)

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I have complex multi-tier architecture in my Android project.

Currently i want to use the following structure of the DI components and modules:

[Data Layer]
    @DataScope //scope is used for caching (Singleton) some Data Layer entities for whole application
    - DataComponent //exposes just interfaces which should be used on the BL Layer
        //Modules exposes entities for internal (Data Layer) injections and entities which exposed by DataComponent for BL Layer
        * DataModule1
        * DataModule2
        * DataModule3

[Business Logic Layer] (also has component dependency on DataComponent)
    @BlScope //scope is used for caching (Singleton) some BL Layer entities for whole application
    - BlComponent //exposes just interfaces which should be used on the Service Layer & Presentation Layer
        //Modules exposes entities for internal (BL Layer) injections and entities which exposed by BLComponent for the Service Layer & Presentation Layer
        * BlModule1
        * BlModule2

[Service Layer] (also has component dependency on BlComponent) - this layer has Android specific entities (Android Service, ContentProvider) not related to the Presentation Layer
    @ServiceScope //scope is used for caching (Singleton) some Service Layer entities for whole application
    - ServiceComponent //exposes just interfaces which should be used on the Presentation Layer
        * ServiceModule //Module exposes entities for internal (Service Layer) injections and entities which exposed by ServiceComponent for the Presentation Layer

[Presentation Layer] (also has component dependency on: ServiceComponent, BlComponent)
    @PresentationScope //scope is used for caching (Singleton) some Presentation Layer entities for whole application
    - PresentationComponent //exposes just interfaces which should be used on the current layer
        * PresentationModule //Module exposes entities injections on the current layer

The ServiceComponent & BlComponent don't expose the similar interfaces.

To build the main graph i use the following code:

DataComponent dataComponent = DaggerDataComponent.builder().<addModules>.build();
BlComponent dataComponent = DaggerBlComponent.builder().<addModules>.dataComponent(dataComponent).build();
ServiceComponent serviceComponent = DaggerServiceComponent.builder().<addModule>.blComponent(blComponent).build();
PresentationComponent presentationComponent = DaggerPresentationComponent.builder().<addModule>.blComponent(blComponent).serviceComponent(serviceComponent).build();

In the PresentationLayer i use only "presentationComponent" to provide required dependencies from ServiceComponent/Layer and BLComponent/Layer.

Currently scenario above doesn't work, because PresentationComponent depends on the 2 scoped components with the error

"...depends on more than one scoped component:..."

Though it allows to use one scoped component with many non-scoped components. This architecture is directed to restrict to use internal layer entities on the upper layers and in the same time to have independent tests (unit & instrumentation) on each layer/module.

Could anybody help me to understand is it bug or desirable behavior of the Dagger processor? (and why?) Issue on the Dagger2 repo: https://github.com/google/dagger/issues/747#issuecomment-303526785

1 Answers
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