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

Fetching data from a network endpoint

For the purpose of this section, we will use The Cat API (https://thecatapi.com/). This RESTful API offers us vast data about, well…cats.

To get started, we will create a new project. We then have to grant our app internet access permission. This is done by adding the following code to your AndroidManifest.xml file right before the Application tag:

<uses-permission
    android:name="android.permission.INTERNET" />

Next, we need to set up our app to include Retrofit. Retrofit is a type-safe library provided by Square, which is built on top of the OkHttp HTTP client. Retrofit helps us generate Uniform Resource Locators (URLs), which are the addresses of the server endpoints we want to access. It also makes the decoding of JSON payloads easier by providing integration with several parsing libraries. Sending data to the server is also easier with Retrofit, as it helps with encoding the requests.

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