Book Image

How to Build Android Apps with Kotlin

By : Alex Forrester, Eran Boudjnah, Alexandru Dumbravan, Jomar Tigcal
Book Image

How to Build Android Apps with Kotlin

By: Alex Forrester, Eran Boudjnah, Alexandru Dumbravan, Jomar Tigcal

Overview of this book

Are you keen to get started building Android 11 apps, but don’t know where to start? How to Build Android Apps with Kotlin is a comprehensive guide that will help kick-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 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. Moving ahead, you'll get to grips with testing, learn how to keep your architecture clean, understand how to persist data, and gain 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 (17 chapters)
12. Dependency Injection with Dagger and Koin


RxJava is a Java implementation of Reactive Extensions (Rx), a library for reactive programming. In reactive programming, you have data streams that can be observed. When the value changes, your observers can be notified and react accordingly. For example, let's say clicking on a button is your observable and you have observers listening to it. If the user clicks on that button, your observers can react and do a specific action.

RxJava makes asynchronous data processing and handling errors simpler. Writing it the usual way is tricky and error-prone. If your task involves a chain of asynchronous tasks, it will be more complicated to write and debug. With RxJava, it can be done more easily and you will have less code, which is more readable and maintainable. RxJava also has a wide range of operators that you can use for transforming data into the type or format you need.

RxJava has three main components: observables, observers, and operators. To use RxJava, you will...