MVIViewModel.kt

class MVIViewModel : ViewModel() {
  val viewState: MutableLiveData<MVIViewState>()
   
  fun fetchData() {
    myDataSource.fetchData()
      .doOnSubscribe {
        viewState.postValue(MVIViewState.Loading)
      }
      .observe(
        {
          viewState.postValue(MVIViewState.Success(it.result))
        },
        {
          viewState.postValue(MVIViewState.Error(it.reason))
        }
      )
  }