Book Image

Clean Android Architecture

By : Alexandru Dumbravan
Book Image

Clean Android Architecture

By: Alexandru Dumbravan

Overview of this book

As an application’s code base increases, it becomes harder for developers to maintain existing features and introduce new ones. In this clean architecture book, you'll learn to identify when and how this problem emerges and how to structure your code to overcome it. The book starts by explaining clean architecture principles and Android architecture components and then explores the tools, frameworks, and libraries involved. You’ll learn how to structure your application in the data and domain layers, the technologies that go in each layer, and the role that each layer plays in keeping your application clean. You’ll understand how to arrange the code into these two layers and the components involved in assembling them. Finally, you'll cover the presentation layer and the patterns that can be applied to have a decoupled and testable code base. By the end of this architecture book, you'll be able to build an application following clean architecture principles and have the knowledge you need to maintain and test the application easily.
Table of Contents (15 chapters)
Part 1 – Introduction
Part 2 – Domain and Data Layers
Part 3 – Presentation Layer

Creating repositories

In this section, we will look at what a repository is and the role it plays in the data layer of an application, and how we can create repositories with various data sources.

The repository represents an abstraction for the data than an application uses, and it is responsible for managing and centralizing the data from one or multiple data sources.

In the previous chapter, we defined the following entity:

data class User(
    val id: String,
    val firstName: String,
    val lastName: String,
    val email: String
) {
    fun getFullName() = "$firstName $lastName"

Here we have a simple User data class with a few relevant fields. The repository abstraction for the User data is as follows:

interface UserRepository {
    fun getUser(id: String): Flow<User>

Here we have an interface named UserRepository that...