RxDataSources

DataSources.kt

class LocalDataSource : DataSource {
  private val localCache: Map<User, List<Task>> =
    mapOf(User(UserId("user1")) to listOf(Task("LocalTask assigned to user1")))

  override fun allTasksByUser(user: User): Observable<List<Task>> = 
    Observable.create { emitter ->
      val cachedUser = localCache[user]
      if (cachedUser != null) {
        emitter.onNext(cachedUser)
      } else {
        emitter.onError(UserNotInLocalStorage(user))
      }
    }
}

class RemoteDataSource : DataSource {
  private val internetStorage: Map<User, List<Task>> =
    mapOf(User(UserId("user2")) to listOf(Task("Remote Task assigned to user2")))

  override fun allTasksByUser(user: User): Observable<List<Task>> = 
    Observable.create { emitter ->
      val networkUser = internetStorage[user]
      if (networkUser != null) {
        emitter.onNext(networkUser)
      } else {
        emitter.onError(UserNotInRemoteStorage(user))
      }
    }
}