Example of declaring subcomponent in module annotation @Module(subcomponents = ...)

Question

What is the use case of declaring subcomponent in dagger module annotation?. e.g.

@Module(subcomponents = ChildComponent.class)
public class ModuleB

I have read the documentation, but couldn't find any example of usage.

Any {@link Subcomponent}- or {@code @ProductionSubcomponent}-annotated classes which should be
   * children of the component in which this module is installed. A subcomponent may be listed in
   * more than one module in a component.

Does this answer your question? [Why are Dagger subcomponents declared in a module and not in the parent component directly?](https://stackoverflow.com/questions/55908839/why-are-dagger-subcomponents-declared-in-a-module-and-not-in-the-parent-componen) — Jeff Bowman, Aug 18 '20 at 17:34

score 0 · Answer 1 · answered Jan 17 '19 at 13:53

0

You can specify Subcomponent classes that should be dependent on Component that your module is child of.

I have component A with module ModuleA and component B. If you specify subcomponents = B.class inside ModuleA, then dagger will not compile giving

error: A doesn't have a @Subcomponent.Builder, which is required when used with @Module.subcomponents
@Module(subcomponents = {B.class})
^

unless component B is subcomponent of A.

answered Jan 17 '19 at 13:53

Tuby

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Yup. But dependencies get resolved? If it is same as subcomponents, what benefits we get using this syntax? – mallaudin Jan 18 '19 at 05:47
I think it is there just for verification – Tuby Jan 18 '19 at 11:09

Example of declaring subcomponent in module annotation @Module(subcomponents = ...)

1 Answers1