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

Controlled Components

A controlled input, or controlled component, is what we will be using most of the time when we want to implement forms in React.

The controlled part comes from the fact that the parent component possesses a reference to the current value that we assign to the input element. That value can be controlled using setState, while managing the state or the value can be passed as a prop from the parent component to its children components.

Let's take a look at the following code snippet:

handleOnNameChange = (e) => {
  this.setState({ name: e.target.value });
};
<input type="text" value={this.state.name} onChange={this.handleOnNameChange} />

To obtain the current value of the input element and for any other updates of that element thereafter, we use the onChange event handler (or any similar handler that triggers when the actual DOM input gets updated). Then, on the event object itself, we get the current value using the e...