users_viewmodel.kt

class ListUsersViewModel(
      private val repository: UserRepository
) : CoroutineViewModel() {

  private val users: MutableLiveData<List<User>> = MutableLiveData()
  private val loading: MutableLiveData<Boolean> = MutableLiveData()
  private val error: MutableLiveData<Throwable> = MutableLiveData()

  fun users() = users as LiveData<List<User>>
  fun loading() = loading as LiveData<Boolean>
  fun error() = error as LiveData<Throwable>

  fun getAll() {
      jobs add launch {
          loading.value = true
          try {
              users.value = repository.getAll().await()
              loading.value = false
          } catch(t: Throwable) {
              users.value = emptyList()
              error.value = t
          } finally {
              loading.value = false
          }
      }
  }

  fun getByUsername(username: String) {
      jobs add launch {
          loading.value = true
          try {
              val user = repository.getByUsername(username).await()
              users.value = listOf(user)
          } catch(t: Throwable) {
              users.value = emptyList()
              error.value = t
          }
          finally {
              loading.value = false
          }
      }
  }

}