Saving Data on Android

LiveData
 and 
ViewModels
.
Saving Data on Android
Chapter 8: The DAO Pattern
raywenderlich.com
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9
Chapter 9: Using Room with 
Google's Architecture 
Components
By Aldo Olivares
In the previous chapters, you learned how to create the most important components 
of a Room Database: your 
data access objects (DAOs)
 and your 
entities
.
While having your DAOs and entities is usually enough to interact with your 
database, you still need a way to display all the information to the user, all the while 
handling lifecycle of the app and configuration changes. This is where Google's 
architecture components such as the 
ViewModel
 and 
LiveData
 come to the rescue!
In this chapter, you will learn:
• What 
LiveData
 and 
ViewModel
 components are, and how to use them.
• How to make your DAOs return 
LiveData
s instead of simple data objects.
• How to create 
ViewModel
s that are