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)

Appendix

Appendix A – Skipping the dispatch

We say that not all dispatched states end up with a change. But actually, not all dispatches end up with a successful dispatch. When a mouse clicks, it goes into the dispatch function. It has a special pathway, and when you hit that condition and find out there's no state change, it can return early without performing a dispatch:

function dispatchAction(fiber, queue, action) {
  ...
    
  if (NoWorkUnderFiber) {
    const currentState = queue.lastRenderedState
    const newState = typeof action === 'function' 
      ? action(currentState) : action
    if (Object.is(newState, currentState)) {
      return
    }
  }
  scheduleUpdateOnFiber(fiber)
}

In the preceding dispatchAction function, a new state is computed...