Book Image

How to Build Android Apps with Kotlin - Second Edition

By : Alex Forrester, Eran Boudjnah, Alexandru Dumbravan, Jomar Tigcal
5 (1)
Book Image

How to Build Android Apps with Kotlin - Second Edition

5 (1)
By: Alex Forrester, Eran Boudjnah, Alexandru Dumbravan, Jomar Tigcal

Overview of this book

Looking to kick-start your app development journey with Android 13, but don’t know where to start? How to Build Android Apps with Kotlin is a comprehensive guide that will help jump-start your Android development practice. This book starts with the fundamentals of app development, enabling you to utilize Android Studio and Kotlin to get started with building Android projects. You'll learn how to create apps and run them on virtual devices through guided exercises. Progressing through the chapters, you'll delve into Android's RecyclerView to make the most of lists, images, and maps, and see how to fetch data from a web service. You'll also get to grips with testing, learning how to keep your architecture clean, understanding how to persist data, and gaining basic knowledge of the dependency injection pattern. Finally, you'll see how to publish your apps on the Google Play store. You'll work on realistic projects that are split up into bitesize exercises and activities, allowing you to challenge yourself in an enjoyable and attainable way. You'll build apps to create quizzes, read news articles, check weather reports, store recipes, retrieve movie information, and remind you where you parked your car. By the end of this book, you'll have the skills and confidence to build your own creative Android applications using Kotlin.
Table of Contents (24 chapters)
1
Part 1: Android Foundation
6
Part 2: Displaying Network Calls
12
Part 3: Testing and Code Structure
17
Part 4: Polishing and Publishing an App

Preferences and DataStore

Imagine you are tasked with integrating a third-party API that uses something such as OAuth to implement logging in with Facebook, Google, and suchlike. The way these mechanisms work is as follows – they give you a token that you have to store locally and that can then be used to send other requests to access user data.

This raises several questions. How can you store that token? Do you use Room just for one token? Do you save the token in a separate file and implement methods for writing the file? What if that file has to be accessed in multiple places at the same time? SharedPreferences and DataStore are answers to these questions. SharedPreferences is a functionality that allows you to save Booleans, integers, floats, longs, strings, and sets of strings into an XML file.

When you want to save new values, you specify what values you want to save for the associated keys, and when you are done, you commit the change, which will trigger the save...