Book Image

Android Studio 4.1 Development Essentials – Kotlin Edition

By : Neil Smyth
Book Image

Android Studio 4.1 Development Essentials – Kotlin Edition

By: Neil Smyth

Overview of this book

Android 11 has a ton of new capabilities. It comes up with three foci: a people-centric approach to communication, controls to let users quickly access and manage all of their smart devices, and privacy to give users more ways to control how data on devices is shared. This book starts off with the steps necessary to set up an Android development and testing environment, followed by an introduction to programming in Kotlin. An overview of Android Studio and its architecture is provided, followed by an in-depth look at the design of Android applications and user interfaces using the Android Studio environment. You will also learn about the Android architecture components along with some advanced topics such as touch screen handling, gesture recognition, the recording and playback of audio, app links, dynamic delivery, the AndroidStudio profiler, Gradle build configuration, and submitting apps to the Google Play Developer Console. The concepts of material design are also covered in detail. This edition of the book also covers printing, transitions, and cloud-based file storage; foldable device support is the cherry on the cake. By the end of this course, you will be able to develop Android 11 Apps using Android Studio 4.1, Kotlin, and Android Jetpack. The code files for the book can be found here: https://www.ebookfrenzy.com/retail/as41kotlin/index.php
Table of Contents (95 chapters)
95
Index

39.9 Repository Modules

If a ViewModel obtains data from one or more external sources (such as databases or web services) it is important to separate the code involved in handling those data sources from the ViewModel class. Failure to do this would, after all, violate the separation of concerns guidelines. To avoid mixing this functionality in with the ViewModel, Google’s architecture guidelines recommend placing this code in a separate Repository module.

A repository is not an Android architecture component, but rather a Java class created by the app developer that is responsible for interfacing with the various data sources. The class then provides an interface to the ViewModel allowing that data to be stored in the model.

Figure 39-4