Book Image

Learning Redux

By : Daniel Bugl
Book Image

Learning Redux

By: Daniel Bugl

Overview of this book

The book starts with a short introduction to the principles and the ecosystem of Redux, then moves on to show how to implement the basic elements of Redux and put them together. Afterward, you are going to learn how to integrate Redux with other frameworks, such as React and Angular. Along the way, you are going to develop a blog application. To practice developing growing applications with Redux, we are going to start from nothing and keep adding features to our application throughout the book. You are going to learn how to integrate and use Redux DevTools to debug applications, and access external APIs with Redux. You are also going to get acquainted with writing tests for all elements of a Redux application. Furthermore, we are going to cover important concepts in web development, such as routing, user authentication, and communication with a backend server After explaining how to use Redux and how powerful its ecosystem can be, the book teaches you how to make your own abstractions on top of Redux, such as higher-order reducers and middleware. By the end of the book, you are going to be able to develop and maintain Redux applications with ease. In addition to learning about Redux, you are going be familiar with its ecosystem, and learn a lot about JavaScript itself, including best practices and patterns.
Table of Contents (13 chapters)

Defining actions

Now that we have defined the state of our application, we also need a way to change the state. In Redux, we never modify the state directly. To ensure that the application is predictable, only actions can change the state. Redux actions are simply JavaScript objects, with a type property that specifies the name of the action. Let's say we want to create a new post in our blog, we could use an action like this:

{ type: 'CREATE_POST', user: 'dan', text: 'New post' } 

Later on, we could define another action for setting the filter:

{ type: 'SET_FILTER', filter: 'hello' }

These action objects can be passed to Redux, resulting in a new state being calculated from the current state and the action. This process is called dispatching an action.

The way state changes are processed in Redux makes them very explicit, clear, and predictable. If you want to find out how a certain state change happened, just look at the action that was dispatched. Furthermore, you can reproduce state changes by reverting and redispatching actions (also known as time traveling).