Book Image

The React Workshop

By : Brandon Richey, Ryan Yu, Endre Vegh, Theofanis Despoudis, Anton Punith, Florian Sloot
5 (1)
Book Image

The React Workshop

5 (1)
By: Brandon Richey, Ryan Yu, Endre Vegh, Theofanis Despoudis, Anton Punith, Florian Sloot

Overview of this book

Are you interested in how React takes command of the view layer for web and mobile apps and changes the data of large web applications without needing to reload the page? This workshop will help you learn how and show you how to develop and enhance web apps using the features of the React framework with interesting examples and exercises. The workshop starts by demonstrating how to create your first React project. You’ll tap into React’s popular feature JSX to develop templates and use DOM events to make your project interactive. Next, you’ll focus on the lifecycle of the React component and understand how components are created, mounted, unmounted, and destroyed. Later, you’ll create and customize components to understand the data flow in React and how props and state communicate between components. You’ll also use Formik to create forms in React to explore the concept of controlled and uncontrolled components and even play with React Router to navigate between React components. The chapters that follow will help you build an interesting image-search app to fetch data from the outside world and populate the data to the React app. Finally, you’ll understand what ref API is and how it is used to manipulate DOM in an imperative way. By the end of this React book, you’ll have the skills you need to set up and create web apps using React.
Table of Contents (20 chapters)
Preface

What Is the Promise API?

As mentioned earlier, the Promise API helps manage asynchronous operations when making network requests to the server. It is a JavaScript object that contains the future values of an async operation, either a resolved value or a reason if it was rejected. A promise has three states:

  • Resolved: The action/operation has succeeded.
  • Rejected: The action/operation is failed.
  • Pending: The action/operation is pending; it's not fulfilled or rejected yet.

We have seen how to fetch data using the promise-based Fetch API in Chapter 14; Fetching Data by Making API Requests, let's review that again and see what values are getting returned.

Let's add the following code in the Chrome Console window:

fetch('https://jsonplaceholder.typicode.com/posts/1')
  .then(function(res) {
    return res.json();
  }).then(function(data) {
    console.log(data);
  ...