UseCase.md

KTAndroidArchitecture - USECASE

1.1 What is UseCase?

A UseCase is basically a wrapper for business logic operations, such as backend calls, data elaboration and so on.

In this specific case a usecase only elaborates the datas provided by a repository and return the elaborated datas. In the execution flow of a usecase we can find this steps:

• The action execute the usecase;
• The usecase calls the repository to get datas;
• The retrieved data get elaborate, by handling error or success results ie.
• The elaborated datas returns to the usecase's calling action.

A usecase have to extend the UseCase abstract class and implement the method run where all the logic is placed, the caller action calls the execute method which calls the run method.

You can use also inline usecases defined in the action execute call.

1.2 Sample

Below a complete example of UseCase:

class LoginUseCase: UseCase<UserLogged, LoginActionParams>() {
    override suspend fun run(params: LoginActionParams): Either<Failure, UserLogged> {
        return AuthRepository.instance.login(params.email, params.password).map { do something }
    }
}

Below a example of inline UseCase:

Action.Builder<LoginActionParams,UserLogged, UIUserLogged>()
        .useCase{return AuthRepository.instance.login(params.email, params.password).map { do something }}
        ...