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 A – Propagating a context

React comes with different kinds of fibers. While a function component is one of them, the context provider is another one. It gets its own update logic with each update:

function updateContextProvider(fiber) {
  var providerType = fiber.type
  var context = providerType._context
  var newProps = fiber.pendingProps
  var oldProps = fiber.memoizedProps
  var newValue = newProps.value
  if (oldProps !== null) { ... }
  var children = newProps.children
  reconcileChildren(fiber, children)
  return fiber.child

In the preceding code, the updateContextProvider function takes in fiber, and checks whether it has been mounted or not via oldProps !== null. If it's a first-time mount, then it does things similar to a function component, reconciling the children into fibers and then returning the first child to work on next.

If it&apos...