MVVM on Android
Notes: 10. Challenge: Create a ViewModel
The clearAllCreatures() method in the AllCreaturesViewModel class uses Kotlin Coroutine and would look like this:
fun clearAllCreatures() = viewModelScope.launch { repository.clearAllCreatures() }
Also AppCompatResources is preffered over context.getDrawable() as the IDE recommends you to do this.
So the code to set the avatarListItem image in the bind() method of the ViewHolder class would be:
binding.avatarListItem.setImageDrawable(
AppCompatResources.getDrawable(
binding.avatarListItem.context,
creature.drawable
)
)
Heads up... You’re accessing parts of this content for free, with some sections shown as text.
Heads up... You’re accessing parts of this content for free, with some sections shown as text.
Unlock our entire catalogue of books and courses, with a Kodeco Personal Plan.
Unlock now
Your next challenge is to put together all you’ve learned so far to build a view model for the app’s first screen that should show the list of all creatures in the repository.
class AllCreaturesViewModel(private val repository: CreatureRepository = RoomRepository()) : ViewModel() {
}
private val allCreaturesLiveData = repository.getAllCreatures()
fun getAllCreaturesLiveData() = allCreaturesLiveData
fun clearAllCreatures() = repository.clearAllCreatures()
private lateinit var viewModel: AllCreaturesViewModel
viewModel = ViewModelProviders.of(this).get(AllCreaturesViewModel::class.java)
viewModel.getAllCreaturesLiveData().observe(this, Observer { creatures ->
creatures?.let {
adapter.updateCreatures(creatures)
}
})
viewModel.clearAllCreatures()
itemView.avatarListItem.setImageDrawable(itemView.context.getDrawable(creature.drawable))
itemView.name.text = creature.name
itemView.hitPoints.text = creature.hitPoints.toString()