react-dom

What is react-dom?

The react-dom package provides DOM-specific methods that can be used at the top level of a web app to enable an efficient way of managing DOM elements in response to data changes. It is a companion package to React that facilitates rendering components to the DOM and interacting with the DOM tree.

What are react-dom's main functionalities?

Rendering React Elements

This feature allows you to render a React element into the DOM in the supplied container and return a reference to the component (or returns null for stateless components).

ReactDOM.render(
  <h1>Hello, world!</h1>,
  document.getElementById('root')
);

Component Lifecycle Management

react-dom manages the lifecycle of components, including mounting, updating, and unmounting components.

class MyComponent extends React.Component {
  componentDidMount() {
    // Code to run when the component is mounted
  }

  componentWillUnmount() {
    // Code to run before the component is unmounted and destroyed
  }
}

Handling Events

react-dom provides a synthetic event system that wraps the native event system, providing a cross-browser interface to native events.

function MyComponent() {
  function handleClick(e) {
    e.preventDefault();
    console.log('The link was clicked.');
  }

  return (
    <a href="#" onClick={handleClick}>
      Click me
    </a>
  );
}

Server-side Rendering

react-dom/server provides methods for rendering components to static markup (typically used on the server) such as renderToString and renderToStaticMarkup.

ReactDOMServer.renderToString(
  <MyComponent />
);

Portals

Portals provide a way to render children into a DOM node that exists outside the DOM hierarchy of the parent component.

ReactDOM.createPortal(
  child,
  container
);

Other packages similar to react-dom

preact

Preact is a fast 3kB alternative to React with the same modern API. It provides similar functionalities for rendering UIs but with a smaller footprint, making it a good choice for performance-sensitive applications.

inferno

Inferno is an extremely fast, React-like library for building high-performance user interfaces on both the client and server. It offers a similar component-based UI building experience but focuses on performance optimizations.

vue-server-renderer

This package is part of the Vue ecosystem and provides server-side rendering capabilities similar to react-dom/server. It's used to render Vue components on the server and send the static markup to the client.

README

react-dom

This package serves as the entry point to the DOM and server renderers for React. It is intended to be paired with the generic React package, which is shipped as react to npm.

Installation

npm install react react-dom

Usage

In the browser

import { createRoot } from 'react-dom/client';

function App() {
  return <div>Hello World</div>;
}

const root = createRoot(document.getElementById('root'));
root.render(<App />);

On the server

import { renderToPipeableStream } from 'react-dom/server';

function App() {
  return <div>Hello World</div>;
}

function handleRequest(res) {
  // ... in your server handler ...
  const stream = renderToPipeableStream(<App />, {
    onShellReady() {
      res.statusCode = 200;
      res.setHeader('Content-type', 'text/html');
      stream.pipe(res);
    },
    // ...
  });
}

API

react-dom

See https://react.dev/reference/react-dom

react-dom/client

See https://react.dev/reference/react-dom/client

react-dom/server

See https://react.dev/reference/react-dom/server