41.4 Summary
This chapter demonstrated the use of the Android LiveData component to make sure that the data displayed to the user always matches that stored in the ViewModel. This relatively simple process consisted of wrapping a ViewModel data value within a LiveData object and setting up an observer within the UI controller subscribed to the LiveData value. Each time the LiveData value changes, the observer is notified and the onChanged() method called and passed the updated value.
Adding LiveData support to the project has gone some way towards simplifying the design of the project. Additional and significant improvements are also possible by making use of the Data Binding Library, details of which will be covered in a later chapter. Before doing that, however, we will look saving ViewModel state.