Book Image

React 16 Essentials - Second Edition

By : Christopher Pitt, Artemij Fedosejev, Adam Boduch
Book Image

React 16 Essentials - Second Edition

By: Christopher Pitt, Artemij Fedosejev, Adam Boduch

Overview of this book

React 16 Essentials, Second Edition, fully updated for React 16, takes you on a fast-paced journey through building your own maintainable React 16 applications. React experts Artemij Fedosejev and Adam Boduch give you all the essentials you need to know and start working with React 16, in this new edition of the best-selling React.js Essentials title. You'll find the latest React 16 code updates, assessment of React Fiber, new coverage of Redux, and how to work as a modern React developer. The authors offer you their current assessment of React Fiber, and you'll soon be exploring React 16 hands on, creating your own single and multiple user interface elements with React 16. You'll then see how to create stateless and stateful components and make them reactive. You'll also learn to interact between your components and lifecycle methods, and gauge how to effectively integrate your user interface components with other JavaScript libraries. Delve deep into the core elements of the Redux architecture and learn how to manage your application and data persistence. Then go the extra mile with the Jest test framework, and run multiple tests on your applications and find solutions to scale without complexity. Today React is used by Facebook, Instagram, Khan Academy, and Imperial College London, to name a few. Many new users recognize the benefits of React and adopt it in their own projects, forming a fast-growing community. The speed at which React has evolved promises a bright future for anyone who invests in learning it today. Let Artemij and Adam bring you a brand new look at React 16 and React Fiber, and move your web development into the future.
Table of Contents (20 chapters)
React 16 Essentials Second Edition
About the Authors
About the Reviewers
Customer Feedback
Free Chapter
What's New in React 16

Controlling state with reducers

The flagship concept of Redux is that, state is controlled by reducer functions. In this section, we'll get you caught up on what reducers are, followed by the implementation of reducer functions in your Snapterest app.

What are reducers?

Reducers are functions that take a data collection, such as an object or an array, and return a new collection. The returned collection can have the same data in it, or it can have completely different data than the initial collection. In Redux applications, reducer functions take a slice of state, and return a new slice of state. That's it! You've just learned the crux of the Redux architecture. Now let's see reducer functions in action.

Reducer functions in Redux applications can be separated into modules that represent the part of the application state they work with. We'll look at the collection reducers, followed by the tweet reducers of the Snapterest app.

Collection reducers

Now let's walk through the collection reducer...