Book Image

Designing React Hooks the Right Way

By : Fang Jin
Book Image

Designing React Hooks the Right Way

By: Fang Jin

Overview of this book

React hook creates a unique solution for using states in function components to orchestrate UI communication. They provide you with an easy interface to write custom data management solutions with low development and maintenance costs. Understanding how Hooks are designed enables you to use them more effectively, and this book helps you to do just that. This book starts with a custom-crafted solution to reveal why Hooks are needed in the first place. You will learn about the React engine and discover how each built-in Hook can manage a persistent value by hooking into it. You will walk through the design and implementation of each hook with code so that you gain a solid understanding. Finally, you'll get to grips with each Hook's pitfalls and find out how to effectively overcome them. By the end of this React book, you'll have gained the confidence to build and write Hooks for developing functional and efficient web applications at scale.
Table of Contents (12 chapters)

Understanding the useContext design

React provides a useContext hook to consume a context:

import UserContext from './UserContext'
const Title = () => {  
  const user = useContext(UserContext)
  return <div>{}</div>

The useContext hook function takes one input argument, context, and returns the shared value. context is normally imported from a definition file.

useContext data structure

We are going to explain how useContext is designed with a stripped-down version of the source code. Let's take a look at the data structure that makes it happen:

Figure 7.4 – useContext hook data structure

To consume (or read) a context value, each fiber gets a new dependencies property to keep track of all the context it consumes. This is because a component can use multiple useContext and each usage consumes a different context, such as UserContext and ThemeContext.

The dependencies...