41.3 Implementing the Observer

Now that the conversion result is contained within a LiveData instance, the next step is to configure an observer within the UI controller which, in this example, is the MainFragment class. Locate the MainFragment.kt class (app -> java -> <package name> -> MainFragment), double-click on it to load it into the editor and modify the onActivityCreated() method to create a new Observer instance named resultObserver:

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import androidx.lifecycle.Observer

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override fun onActivityCreated(savedInstanceState: Bundle?) {

    super.onActivityCreated(savedInstanceState)

    viewModel = ViewModelProvider(this).get(MainViewModel::class.java)

 

    resultText.text = viewModel.getResult().toString()

 

    val resultObserver = Observer<Float> {

            ...