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

Data streams

When it comes to data observability, we have multiple approaches for implementation, whether manually built mechanisms, components from the Java language, third-party components, or finally to solutions developed particularly for Android. When it comes to Android, some of the most common solutions are LiveData, Flows from the Coroutines components, and RxJava.

The first one we will look at is LiveData, as it is part of the Android Architecture Components, which means that it is tailored specially to Android. We will then look at how we can use other types of data streams, which we will cover in more depth in future chapters.

LiveData

LiveData is a lifecycle-aware component that permits updates to your UI, but only if the UI is in an active state (for example, if the activity or fragment is in one of the STARTED or RESUMED states). To monitor changes on LiveData, you need an observer combined with a LifecycleOwner. When the activity is set to an active state, the...