commonViewModel.kt

class CommonViewModel(private val api: MockApi = MockService()) : ViewModel() // 생성자 구조

private val _uiModels = MutableLiveData<List<NormalUiModel>>(emptyList())
val uiModels: LiveData<List<NormalUiModel>> = _uiModels
val uiModelsValue get() = uiModels.value ?: emptyList()

fun loadMoreUiModels() {
    if (requestLock.getAndSet(true)) return
    isShowProgress.value = true
    api.loadMore()
        .map { NormalModelMapper.from(it) }
        .doFinally {
            requestLock.set(false)
            isShowProgress.postValue(false)
        }
        .subscribe({
            _uiModels.postValue(uiModelsValue + it)
        }, {
            _throwable.postValue(it)
        }).addTo(compositeDisposable)
}