What is rehype?
Rehype is a powerful HTML processor built on the unified framework. It allows you to parse, transform, and stringify HTML content. It is highly extensible and can be used for a variety of tasks such as sanitizing HTML, extracting content, and transforming HTML structures.
What are rehype's main functionalities?
Parsing HTML
Rehype can parse HTML strings into a syntax tree, which can then be manipulated or analyzed.
const rehype = require('rehype');
const html = '<h1>Hello, world!</h1>';
rehype().parse(html);
Transforming HTML
Rehype allows you to transform HTML content by manipulating the syntax tree. You can use plugins or custom functions to modify the tree.
const rehype = require('rehype');
const html = '<h1>Hello, world!</h1>';
rehype()
.use(() => (tree) => {
// Transform the tree
})
.process(html)
.then((file) => {
console.log(String(file));
});
Stringifying HTML
Rehype can convert a syntax tree back into an HTML string, allowing you to output the transformed content.
const rehype = require('rehype');
const tree = { type: 'root', children: [{ type: 'element', tagName: 'h1', properties: {}, children: [{ type: 'text', value: 'Hello, world!' }] }] };
rehype().stringify(tree);
Sanitizing HTML
Rehype can be used to sanitize HTML content, removing potentially dangerous elements and attributes.
const rehype = require('rehype');
const rehypeSanitize = require('rehype-sanitize');
const html = '<script>alert("Hello, world!")</script><p>Safe content</p>';
rehype()
.use(rehypeSanitize)
.process(html)
.then((file) => {
console.log(String(file));
});
Other packages similar to rehype
htmlparser2
Htmlparser2 is a fast and forgiving HTML/XML parser. It is similar to rehype in that it can parse HTML into a tree structure, but it is more focused on speed and less on extensibility and transformations.
jsdom
Jsdom is a JavaScript implementation of the DOM and HTML standards. It allows you to manipulate HTML content in a way similar to how you would in a browser. Unlike rehype, jsdom provides a full DOM API, making it more suitable for complex manipulations and simulations of browser environments.
cheerio
Cheerio is a fast, flexible, and lean implementation of core jQuery designed specifically for the server. It allows you to parse and manipulate HTML using a jQuery-like syntax. While rehype focuses on transformations and extensibility, cheerio is more about providing a familiar API for DOM manipulation.
rehype
unified processor to parse and compile HTML.
Powered by plugins.
Part of the unified collective.
Don’t need the parser?
Or the compiler?
That’s OK.
If you’re in a browser, trust the content, and value a smaller bundle size, use
rehype-dom
instead.
Read more about the unified collective on Medium »
Install
npm:
npm install rehype
Use
var rehype = require('rehype')
var report = require('vfile-reporter')
rehype().process('<title>Hi</title><h2>Hello world!', function(err, file) {
console.log(report(err || file))
console.log(String(file))
})
Yields:
no issues found
<html><head><title>Hi</title></head><body><h2>Hello world!</h2></body></html>
Configuration for rehype-parse
and rehype-stringify
can be set with .data('settings', {/*...*/})
.
Security
As rehype works on HTML, and improper use of HTML can open you up to a
cross-site scripting (XSS) attack, use of rehype can also be unsafe.
Use rehype-sanitize
to make the tree safe.
Contribute
See contributing.md
in rehypejs/.github
for ways
to get started.
See support.md
for ways to get help.
Ideas for new plugins and tools can be posted in rehypejs/ideas
.
A curated list of awesome rehype resources can be found in awesome
rehype.
This project has a Code of Conduct.
By interacting with this repository, organisation, or community you agree to
abide by its terms.
License
MIT © Titus Wormer