submit_request.kt

// Result class of the SubmitName action
sealed class Result {
	sealed class SubmitResult : Result() {
		object Success: SubmitResult()
		object InFlight: SubmitResult()
		data class Failure(val errorMessage: String): SubmitResult()
	}
}

private val submitName: ObservableTransformer<SubmitNameAction, SubmitResult> =
    ObservableTransformer { actions ->
        actions.flatMap { event ->
            repository.sendName(event.name) // The asynchronous call
                .andThen(Observable.just(SubmitResult.Success as SubmitResult))
                .onErrorReturn { SubmitResult.Failure(it.message ?: "Your error message") }
                 .observeOn(AndroidSchedulers.mainThread())
                .startWith(SubmitResult.InFlight)
        }
    }