Book Image

Simplifying Android Development with Coroutines and Flows

By : Jomar Tigcal
Book Image

Simplifying Android Development with Coroutines and Flows

By: Jomar Tigcal

Overview of this book

Coroutines and flows are the new recommended way for developers to carry out asynchronous programming in Android using simple, modern, and testable code. This book will teach you how coroutines and flows work and how to use them in building Android applications, along with helping you to develop modern Android applications with asynchronous programming using real data. The book begins by showing you how to create and handle Kotlin coroutines on Android. You’ll explore asynchronous programming in Kotlin, and understand how to test Kotlin coroutines. Next, you'll learn about Kotlin flows on Android, and have a closer look at using Kotlin flows by getting to grips with handling flow cancellations and exceptions and testing the flows. By the end of this book, you'll have the skills you need to build high-quality and maintainable Android applications using coroutines and flows.
Table of Contents (11 chapters)
Part 1 – Kotlin Coroutines on Android
Part 2 – Kotlin Flows on Android

Catching exceptions in Flows

The Flows in your code can encounter CancellationException when they are canceled or other exceptions when emitting or collecting values. In this section, we will learn how to handle these Kotlin Flow exceptions.

Exceptions can happen in Flows during the collection of values or when using any operators on a Flow. We can handle exceptions in Flows by enclosing the collection of the Flow in our code with a try-catch block. For example, in the following code, the try-catch block is used to add exception handling:

class MainActivity : AppCompatActivity() {
 override fun onCreate(savedInstanceState: Bundle?) {
     lifecycleScope.launch {
         repeatOnLifecycle(Lifecycle.State.STARTED) {
             try {