Example.kt

// Copyright: https://developer.android.com/topic/libraries/architecture/livedata
class NameViewModel : ViewModel() {

    // Create a LiveData with a String
    val currentName: MutableLiveData<String> by lazy {
        MutableLiveData<String>()
    }

    // Rest of the ViewModel...
}


class NameActivity : AppCompatActivity() {

    private lateinit var mModel: NameViewModel

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        // Other code to setup the activity...

        // Get the ViewModel.
        mModel = ViewModelProviders.of(this).get(NameViewModel::class.java)


        // Create the observer which updates the UI.
        val nameObserver = Observer<String> { newName ->
            // Update the UI, in this case, a TextView.
            mNameTextView.text = newName
        }

        // Observe the LiveData, passing in this activity as the LifecycleOwner and the observer.
        mModel.currentName.observe(this, nameObserver)
    }
}