Use variable from ViewModel in Activity. Best practices

Question

I have three List on the VM that I want to use in the activity. These Lists won't change on time, will always be the same, so it is not a State. Should I do the following on the activity?

private val gymListViewModel: GymListViewModel by viewModels()
val myList1 = gymListViewModel.list1
val myList2 = gymListViewModel.list2
val myList3 = gymListViewModel.list3

Is that correct? Or what I should do is use LiveData or Flow to be listening on the activity? Or maybe I should create a data class with three val so I just call that object on the activity?

The other thing that I've been thinking is to call the method that populates the lists, something like: val myList1 = gymListViewModel.getList1() But if I'm not wrong, it's supposed that the VM should not have returning methods, they just update the state. I'm asking this in terms of best practices. Thanks

Answer 1

You can directly access the lists from the ViewModel without involving LiveData or Flow if they are static and immutable.

class GymListViewModel : ViewModel() {
    val list1: List<String> = listOf("Item1", "Item2", "Item3")
    val list2: List<String> = listOf("Item4", "Item5", "Item6")
    val list3: List<String> = listOf("Item7", "Item8", "Item9")
}

class GymActivity : AppCompatActivity() {
    private val gymListViewModel: GymListViewModel by viewModels()

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_gym)

        val myList1 = gymListViewModel.list1
        val myList2 = gymListViewModel.list2
        val myList3 = gymListViewModel.list3

        // Use the lists as needed
    }
}