Book Image

Redux Quick Start Guide

By : James Lee, Tao Wei, Suresh Kumar Mukhiya
Book Image

Redux Quick Start Guide

By: James Lee, Tao Wei, Suresh Kumar Mukhiya

Overview of this book

Starting with a detailed overview of Redux, we will follow the test-driven development (TDD) approach to develop single-page applications. We will set up JEST for testing and use JEST to test React, Redux, Redux-Sage, Reducers, and other components. We will then add important middleware and set up immutableJS in our application. We will use common data structures such as Map, List, Set, and OrderedList from the immutableJS framework. We will then add user interfaces using ReactJS, Redux-Form, and Ant Design. We will explore the use of react-router-dom and its functions. We will create a list of routes that we will need in order to create our application, and explore routing on the server site and create the required routes for our application. We will then debug our application and integrate Redux Dev tools. We will then set up our API server and create the API required for our application. We will dive into a modern approach to structuring our server site components in terms of Model, Controller, Helper functions, and utilities functions. We will explore the use of NodeJS with Express to build the REST API components. Finally, we will venture into the possibilities of extending the application for further research, including deployment and optimization.
Table of Contents (16 chapters)
Title Page
Copyright and Credits
About Packt

Fundamental principles of Redux

Redux makes it possible to store all statuses in an application in a single place, which is called a store. A store is the intermediary to all of the changes of the status of the app. Using Redux, a component cannot communicate directly with another component; instead, the changes always go through a single source, which is an action. Redux can be described simply by three fundamental principles. Those three main principles, which will be briefly explained in this chapter, are summarized as follows:

  • A single source of truth
  • The read-only nature of the state
  • The reducer principle

Single source of truth

The whole application state is stored in a single object, called the state tree. This makes it easier to create modern applications, as the server state can easily be serialized and hydrated to client apps.

An example for an online medical store app is as follows:

Read-only nature of the state

Emitting an action is the only way to change the state of a Redux app. Views cannot directly write to the state tree. In Redux, every intent needs to dispatch actions, which tell the reducers (a function) to transform the state. Mutating the state is also not recommended; hence, every time, the reducers write the existing state object with the new version:

The reducer principle – changes are made with pure functions

The transformation logic of the state tree is specified with the use of pure functions, called reducers. Reducers are special functions that take the current state and action to return a new state, without mutating the state.