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)
Preface
12
12. Dependency Injection with Dagger and Koin

Dagger

Dagger offers a comprehensive way to organize your application's dependencies. It has the advantage of being adopted first on Android by the developer community before Kotlin was introduced. This is one of the reasons that many Android applications use Dagger as their DI framework. Another advantage the framework holds is for Android projects written in Java, because the library is developed in the same language. The framework was initially developed by Square (Dagger 1) and later transitioned to Google (Dagger 2). We will cover Dagger 2 in this chapter and describe its benefits. Some of the key functionalities Dagger 2 provides are the following:

  • Injection
  • Dependencies grouped in modules
  • Components used to generate dependency graphs
  • Qualifiers
  • Scopes
  • Subcomponents

Annotations are the key elements when dealing with Dagger, because it generates the code required to perform the DI through an annotation processor. The main annotations can...