Singleton UseCase? about clean-architecture-android-kotlin HOT 3 CLOSED

I think the Rx subscription may not be related to singleton use case.

The Rx subscription will be disposed when Activity's lifecycle goes to onDestroy, but it won't destroy the use case instance. The whole idea is each use case responsible for a different business logic, and it can be shared between multiple Presenters.

e.g.
ArticleListPresenter is a consumer of GetArticleListUseCase and GetArticleTypeUseCase, it shows articles list and types list on that screen.
Imagine we got another screen, then we have a presenter called DashboardPresenter, this screen shows multiple sections(article list, user list, message list), so this DashboardPresenter is a consumer of GetArticleListUseCase too, the first time when user open article list screen, GetArticleListUseCase makes a network request and then hold the data, on the next screen, the DashboardPresenter uses the same UseCase instance rather than create a new instance, it would have a better performance(it doesn't need to make a new network call). and it can be shared data between multiple screens.

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The idea is good, but your implementation will not allow it. Your use case is not a memory cache, it will perform a repeated network call when you call execute. But rotate the screen or press back and open the application and your network call will be canceled at all, because you called it after dispose(). Perhaps you need to recreate CompositeDisposable, or you can use the clear().

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That is an example and I didn't implement the memory cache on domain layer at the moment, the current use case doesn't have memory cache, it will make a new call every time when the consumer subscribes it, we could simply add .replay() to the Rx chain, then it won't make new request after the first network call.

For the 2nd issue you mentioned:
Yes, I agree, the current use case is a singleton object, the use case and CompositeDisposable won't be re-created after rotates. I didn't notice that before. Thanks for your contribution @AntonKulykov , I'll fix it.

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