@leafwell/html-react-parser

v5.0.6

Published

a year ago

HTML to React parser.

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mnogueira27

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html-react-parser html react parser dom

html-react-parser

HTML to React parser that works on both the server (Node.js) and the client (browser):

HTMLReactParser(string[, options])

The parser converts an HTML string to one or more React elements.

To replace an element with another element, check out the replace option.

Example

import parse from 'html-react-parser';

parse('<p>Hello, World!</p>'); // React.createElement('p', {}, 'Hello, World!')

Install

NPM:

npm install html-react-parser --save

Yarn:

yarn add html-react-parser

CDN:

<!-- HTMLReactParser depends on React -->
<script src="https://unpkg.com/react@18/umd/react.production.min.js"></script>
<script src="https://unpkg.com/html-react-parser@latest/dist/html-react-parser.min.js"></script>
<script>
  window.HTMLReactParser(/* string */);
</script>

Usage

Import ES module:

import parse from 'html-react-parser';

Or require CommonJS module:

const parse = require('html-react-parser').default;

Parse single element:

parse('<h1>single</h1>');

Parse multiple elements:

parse('<li>Item 1</li><li>Item 2</li>');

Make sure to render parsed adjacent elements under a parent element:

<ul>
  {parse(`
    <li>Item 1</li>
    <li>Item 2</li>
  `)}
</ul>

Parse nested elements:

parse('<body><p>Lorem ipsum</p></body>');

Parse element with attributes:

parse(
  '<hr id="foo" class="bar" data-attr="baz" custom="qux" style="top:42px;">',
);

replace

The replace option allows you to replace an element with another element.

The replace callback's first argument is domhandler's node:

parse('<br>', {
  replace(domNode) {
    console.dir(domNode, { depth: null });
  },
});

Element {
  type: 'tag',
  parent: null,
  prev: null,
  next: null,
  startIndex: null,
  endIndex: null,
  children: [],
  name: 'br',
  attribs: {}
}

The element is replaced if a valid React element is returned:

parse('<p id="replace">text</p>', {
  replace(domNode) {
    if (domNode.attribs && domNode.attribs.id === 'replace') {
      return <span>replaced</span>;
    }
  },
});

replace with TypeScript

For TypeScript, you'll need to check that domNode is an instance of domhandler's Element:

import { HTMLReactParserOptions, Element } from 'html-react-parser';

const options: HTMLReactParserOptions = {
  replace(domNode) {
    if (domNode instanceof Element && domNode.attribs) {
      // ...
    }
  },
};

Or use a type assertion:

import { HTMLReactParserOptions, Element } from 'html-react-parser';

const options: HTMLReactParserOptions = {
  replace(domNode) {
    if ((domNode as Element).attribs) {
      // ...
    }
  },
};

If you're having issues take a look at our Create React App example.

replace element and children

Replace the element and its children (see demo):

import parse, { domToReact } from 'html-react-parser';

const html = `
  <p id="main">
    <span class="prettify">
      keep me and make me pretty!
    </span>
  </p>
`;

const options = {
  replace({ attribs, children }) {
    if (!attribs) {
      return;
    }

    if (attribs.id === 'main') {
      return <h1 style={{ fontSize: 42 }}>{domToReact(children, options)}</h1>;
    }

    if (attribs.class === 'prettify') {
      return (
        <span style={{ color: 'hotpink' }}>
          {domToReact(children, options)}
        </span>
      );
    }
  },
};

parse(html, options);

<h1 style="font-size:42px">
  <span style="color:hotpink">
    keep me and make me pretty!
  </span>
</h1>

replace element attributes

Convert DOM attributes to React props with attributesToProps:

import parse, { attributesToProps } from 'html-react-parser';

const html = `
  <main class="prettify" style="background: #fff; text-align: center;" />
`;

const options = {
  replace(domNode) {
    if (domNode.attribs && domNode.name === 'main') {
      const props = attributesToProps(domNode.attribs);
      return <div {...props} />;
    }
  },
};

parse(html, options);

<div class="prettify" style="background:#fff;text-align:center"></div>

replace and remove element

Exclude an element from rendering by replacing it with <React.Fragment>:

parse('<p><br id="remove"></p>', {
  replace: ({ attribs }) => attribs?.id === 'remove' && <></>,
});

<p></p>

transform

The transform option allows you to transform each element individually after it's parsed.

The transform callback's first argument is the React element:

parse('<br>', {
  transform(reactNode, domNode, index) {
    // this will wrap every element in a div
    return <div>{reactNode}</div>;
  },
});

library

The library option specifies the UI library. The default library is React.

To use Preact:

parse('<br>', {
  library: require('preact'),
});

Or a custom library:

parse('<br>', {
  library: {
    cloneElement: () => {
      /* ... */
    },
    createElement: () => {
      /* ... */
    },
    isValidElement: () => {
      /* ... */
    },
  },
});

htmlparser2

Warning: htmlparser2 options do not work on the client-side (browser) and the options only work on the server-side (Node.js). By overriding the options, it could cause universal rendering to break.

Default htmlparser2 options can be overridden in >=0.12.0.

To enable xmlMode:

parse('<p /><p />', {
  htmlparser2: {
    xmlMode: true,
  },
});

trim

By default, whitespace is preserved:

parse('<br>\n'); // [React.createElement('br'), '\n']

But certain elements like <table> will strip out invalid whitespace:

parse('<table>\n</table>'); // React.createElement('table')

To remove whitespace, enable the trim option:

parse('<br>\n', { trim: true }); // React.createElement('br')

However, intentional whitespace may be stripped out:

parse('<p> </p>', { trim: true }); // React.createElement('p')

Migration

v5

Migrated to TypeScript. CommonJS imports require the .default key:

const parse = require('html-react-parser').default;

If you're getting the error:

Argument of type 'ChildNode[]' is not assignable to parameter of type 'DOMNode[]'.

Then use type assertion:

domToReact(domNode.children as DOMNode[], options);

See #1126.

v4

htmlparser2 has been upgraded to v9.

v3

domhandler has been upgraded to v5 so some parser options like normalizeWhitespace have been removed.

Also, it's recommended to upgrade to the latest version of TypeScript.

v2

Since v2.0.0, Internet Explorer (IE) is no longer supported.

v1

TypeScript projects will need to update the types in v1.0.0.

For the replace option, you may need to do the following:

import { Element } from 'domhandler/lib/node';

parse('<br class="remove">', {
  replace(domNode) {
    if (domNode instanceof Element && domNode.attribs.class === 'remove') {
      return <></>;
    }
  },
});

Since v1.1.1, Internet Explorer 9 (IE9) is no longer supported.

FAQ

Is this XSS safe?

No, this library is not XSS (cross-site scripting) safe. See #94.

Does invalid HTML get sanitized?

No, this library does not sanitize HTML. See #124, #125, and #141.

Are `<script>` tags parsed?

Although <script> tags and their contents are rendered on the server-side, they're not evaluated on the client-side. See #98.

Attributes aren't getting called

The reason why your HTML attributes aren't getting called is because inline event handlers (e.g., onclick) are parsed as a string rather than a function. See #73.

Parser throws an error

If the parser throws an error, check if your arguments are valid. See "Does invalid HTML get sanitized?".

Is SSR supported?

Yes, server-side rendering on Node.js is supported by this library. See demo.

Elements aren't nested correctly

If your elements are nested incorrectly, check to make sure your HTML markup is valid. The HTML to DOM parsing will be affected if you're using self-closing syntax (/>) on non-void elements:

parse('<div /><div />'); // returns single element instead of array of elements

See #158.

Don't change case of tags

Tags are lowercased by default. To prevent that from happening, pass the htmlparser2 option:

const options = {
  htmlparser2: {
    lowerCaseTags: false,
  },
};
parse('<CustomElement>', options); // React.createElement('CustomElement')

Warning: By preserving case-sensitivity of the tags, you may get rendering warnings like:
Warning: <CustomElement> is using incorrect casing. Use PascalCase for React components, or lowercase for HTML elements.

See #62 and example.

TS Error: Property 'attribs' does not exist on type 'DOMNode'

The TypeScript error occurs because DOMNode needs to be an instance of domhandler's Element. See migration or #199.

Can I enable `trim` for certain elements?

Yes, you can enable or disable trim for certain elements using the replace option. See #205.

Webpack build warnings

If you see the Webpack build warning:

export 'default' (imported as 'parse') was not found in 'html-react-parser'

Then update your Webpack config to:

// webpack.config.js
module.exports = {
  // ...
  resolve: {
    mainFields: ['browser', 'main', 'module'],
  },
};

See #238 and #213.

TypeScript error

If you see the TypeScript error:

node_modules/htmlparser2/lib/index.d.ts:2:23 - error TS1005: ',' expected.

2 export { Parser, type ParserOptions };
                        ~~~~~~~~~~~~~

Then upgrade to the latest version of typescript. See #748.

Performance

Run benchmark:

npm run benchmark

Output of benchmark run on MacBook Pro 2021:

html-to-react - Single x 1,018,239 ops/sec ±0.43% (94 runs sampled)
html-to-react - Multiple x 380,037 ops/sec ±0.61% (97 runs sampled)
html-to-react - Complex x 35,091 ops/sec ±0.50% (96 runs sampled)

Run Size Limit: