Book Image

Learn React with TypeScript 3

By : Carl Rippon
Book Image

Learn React with TypeScript 3

By: Carl Rippon

Overview of this book

React today is one of the most preferred choices for frontend development. Using React with TypeScript enhances development experience and offers a powerful combination to develop high performing web apps. In this book, you’ll learn how to create well structured and reusable react components that are easy to read and maintain by leveraging modern web development techniques. We will start with learning core TypeScript programming concepts before moving on to building reusable React components. You'll learn how to ensure all your components are type-safe by leveraging TypeScript's capabilities, including the latest on Project references, Tuples in rest parameters, and much more. You'll then be introduced to core features of React such as React Router, managing state with Redux and applying logic in lifecycle methods. Further on, you'll discover the latest features of React such as hooks and suspense which will enable you to create powerful function-based components. You'll get to grips with GraphQL web API using Apollo client to make your app more interactive. Finally, you'll learn how to write robust unit tests for React components using Jest. By the end of the book, you'll be well versed with all you need to develop fully featured web apps with React and TypeScript.
Table of Contents (14 chapters)

Lazy loading routes

At the moment, all the JavaScript for our app is loaded when the app first loads. This includes the Admin page that users don't use that often. It would be great if the AdminPage component wasn't loaded when the app loads and instead loaded on demand. This is exactly what we are going to do in this section. This is called "lazy loading" components. The following steps allows us to load things on demand:

  1. First, we are going to import the Suspense component from React, which we are going to use a little later:
import { Suspense } from "react";
  1. Now, we are going to import the AdminPage component differently:
const AdminPage = React.lazy(() => import("./AdminPage"));

We use a React function called lazy which takes in a function that returns a dynamic import, which in turn is assigned to our AdminPage component variable...