Book Image

React Design Patterns and Best Practices. - Second Edition

Book Image

React Design Patterns and Best Practices. - Second Edition

Overview of this book

React is an adaptable JavaScript library for building complex UIs from small, detached bits called components. This book is designed to take you through the most valuable design patterns in React, helping you learn how to apply design patterns and best practices in real-life situations. You’ll get started by understanding the internals of React, in addition to covering Babel 7 and Create React App 2.0, which will help you write clean and maintainable code. To build on your skills, you will focus on concepts such as class components, stateless components, and pure components. You'll learn about new React features, such as the context API and React Hooks that will enable you to build components, which will be reusable across your applications. The book will then provide insights into the techniques of styling React components and optimizing them to make applications faster and more responsive. In the concluding chapters, you’ll discover ways to write tests more effectively and learn how to contribute to React and its ecosystem. By the end of this book, you will be equipped with the skills you need to tackle any developmental setbacks when working with React. You’ll be able to make your applications more flexible, efficient, and easy to maintain, thereby giving your workflow a boost when it comes to speed, without reducing quality.
Table of Contents (19 chapters)
Free Chapter
1
Section 1: Hello React!
4
Section 2: How React works
9
Section 3: Performance, Improvements and Production!

Mutating the state

React comes with a very clear and straightforward API to mutate the internal state of components. Using the setState function, we can tell the library how we want the state to be changed. As soon as the state is updated, React re-renders the component, and we can access the new state through the this.state property—that's it.

Sometimes, however, we could make the mistake of mutating the state object directly, leading to dangerous consequences for the component's consistency and performance.

First of all, if we mutate the state without using setState, two bad things can happen:

  • The state changes without making the component re-render
  • Whenever setState gets called in the future, the mutated state gets applied

If we go back to the counter example and change the click handler to the following, we can see that clicking + does not affect the rendered...