react-html-parser

What is react-html-parser?

The react-html-parser npm package is used to parse HTML strings into React components. This allows developers to dynamically render HTML content within their React applications.

What are react-html-parser's main functionalities?

Basic HTML Parsing

This feature allows you to parse a basic HTML string and render it as React components. The HTML string is converted into React elements that can be rendered in the application.

const React = require('react');
const ReactDOM = require('react-dom');
const ReactHtmlParser = require('react-html-parser');

const htmlString = '<div><h1>Hello, World!</h1><p>This is a paragraph.</p></div>';
const App = () => (
  <div>
    {ReactHtmlParser(htmlString)}
  </div>
);

ReactDOM.render(<App />, document.getElementById('root'));

Handling Inline Styles

This feature allows you to parse HTML strings that include inline styles. The styles are preserved and applied to the rendered React components.

const React = require('react');
const ReactDOM = require('react-dom');
const ReactHtmlParser = require('react-html-parser');

const htmlString = '<div style="color: red;"><h1>Hello, World!</h1><p>This is a paragraph with inline styles.</p></div>';
const App = () => (
  <div>
    {ReactHtmlParser(htmlString)}
  </div>
);

ReactDOM.render(<App />, document.getElementById('root'));

Custom Transformations

This feature allows you to apply custom transformations to specific HTML elements during the parsing process. In this example, the <h1> tag is transformed to have a blue color.

const React = require('react');
const ReactDOM = require('react-dom');
const ReactHtmlParser = require('react-html-parser');

const htmlString = '<div><h1>Hello, World!</h1><p>This is a paragraph.</p></div>';

const transform = (node) => {
  if (node.type === 'tag' && node.name === 'h1') {
    return <h1 style={{ color: 'blue' }}>{node.children[0].data}</h1>;
  }
};

const App = () => (
  <div>
    {ReactHtmlParser(htmlString, { transform })}
  </div>
);

ReactDOM.render(<App />, document.getElementById('root'));

Other packages similar to react-html-parser

html-react-parser

html-react-parser is a similar package that parses HTML strings into React components. It offers a more modern and actively maintained alternative to react-html-parser, with additional features like support for custom processing instructions and better handling of complex HTML structures.

react-dom-parser

react-dom-parser is another package that converts HTML strings into React elements. It focuses on providing a simple and lightweight solution for rendering HTML content in React applications, with a straightforward API and minimal dependencies.

react-render-html

react-render-html is a package that allows you to render HTML strings as React components. It provides a simple API for converting HTML content into React elements, with support for custom transformations and event handling.

README

React HTML Parser

A utility for converting HTML strings into React components. Avoids the use of dangerouslySetInnerHTML and converts standard HTML elements, attributes and inline styles into their React equivalents.

Try the Live Demo

Install

npm install react-html-parser
# or
yarn add react-html-parser

Usage

import React from 'react';
import ReactHtmlParser, { processNodes, convertNodeToElement, htmlparser2 } from 'react-html-parser';

class HtmlComponent extends React.Component {
  render() {
    const html = '<div>Example HTML string</div>';
    return <div>{ ReactHtmlParser(html) }</div>;
  }
}

API

function ReactHtmlParser(html, [options])

Takes an HTML string and returns equivalent React elements

Usage

import ReactHtmlParser from 'react-html-parser';

Arguments

• html: The HTML string to parse
• options: Options object
  • decodeEntities=true (boolean): Whether to decode html entities (defaults to true)
  • transform (function): Transform function that is applied to every node
  • preprocessNodes (function): Pre-process the nodes generated by htmlparser2

Transform Function

The transform function will be called for every node that is parsed by the library.

function transform(node, index)

Arguments

• node: The node being parsed. This is the htmlparser2 node object. Full details can be found on their project page but important properties are:
  • type (string): The type of node (tag, text, style etc)
  • name (string): The name of the node
  • children (array): Array of children nodes
  • next (node): The node's next sibling
  • prev (node): The node's previous sibling
  • parent (node): The node's parent
  • data (string): The text content, if the type is text
• index (number): The index of the node in relation to it's parent

Return Types

return null Returning null will prevent the node and all of it's children from being rendered.

function transform(node) {
  // do not render any <span> tags
  if (node.type === 'tag' && node.name === 'span') {
    return null;
  }
}

return undefined If the function does not return anything, or returns undefined, then the default behaviour will occur and the parser will continue was usual.

return React element React elements can be returned directly

import React from 'react';
function transform(node) {
  if (node.type === 'tag' && node.name === 'b') {
    return <div>This was a bold tag</div>;
  }
}

preprocessNodes Function

Allows pre-processing the nodes generated from the html by htmlparser2 before being passed to the library and converted to React elements.

function preprocessNodes(nodes)

Arguments

• nodes: The entire node tree generated by htmlparser2.

Return type

The preprocessNodes function should return a valid htmlparser2 node tree.

function convertNodeToElement(node, index, transform)

Processes a node and returns the React element to be rendered. This function can be used in conjunction with the previously described transform function to continue to process a node after modifying it.

Usage

import { convertNodeToElement } from 'react-html-parser';

Arguments

• node: The node to process
• index (number): The index of the node in relation to it's parent
• transform: The transform function as described above

import { convertNodeToElement } from 'react-html-parser';
function transform(node, index) {
  // convert <ul> to <ol>
  if (node.type === 'tag' && node.name === 'ul') {
    node.name = 'ol';
    return convertNodeToElement(node, index, transform);
  }
}

htmlparser2

The library exposes the htmlparser2 library it uses. This allows consumers to use it without having to add it as a separate dependency.

See https://github.com/fb55/htmlparser2 for full details.

Changelog

v2.0.2

Bug Fixes

• Fix empty inline style attribute breaking rendering #34 (kevinzwhuang)