unified

Project: rehypejs/rehype

Package: rehype-stringify@9.0.3

  1. Dependents: 0
  2. rehype plugin to serialize HTML
  1. unified 180
  2. plugin 140
  3. html 124
  4. rehype 91
  5. rehype-plugin 63
  6. tree 41
  7. ast 34
  8. syntax 27
  9. stringify 18
  10. compile 13
  11. serialize 11
  12. abstract 10

rehype-stringify

Build Coverage Downloads Size Sponsors Backers Chat

rehype plugin to add support for serializing HTML.

Contents

What is this?

This package is a unified (rehype) plugin that defines how to take a syntax tree as input and turn it into serialized HTML. When it’s used, HTML is serialized as the final result.

See the monorepo readme for info on what the rehype ecosystem is.

When should I use this?

This plugin adds support to unified for serializing HTML. You can alternatively use rehype instead, which combines unified, rehype-parse, and this plugin.

When you’re in a browser, trust your content, don’t need formatting options, and value a smaller bundle size, you can use rehype-dom-stringify instead.

This plugin is built on hast-util-to-html, which turns hast syntax trees into a string. rehype focusses on making it easier to transform content by abstracting such internals away.

A different plugin, rehype-format, improves the readability of HTML source code as it adds insignificant but pretty whitespace between elements. There is also the preset rehype-minify for when you want the inverse: minified and mangled HTML.

Install

This package is ESM only. In Node.js (version 12.20+, 14.14+, or 16.0+), install with npm:

npm install rehype-stringify

In Deno with esm.sh:

import rehypeStringify from 'https://esm.sh/rehype-stringify@9'

In browsers with esm.sh:

<script type="module">
  import rehypeStringify from 'https://esm.sh/rehype-stringify@9?bundle'
</script>

Use

Say we have the following module example.js:

import {unified} from 'unified'
import remarkParse from 'remark-parse'
import remarkGfm from 'remark-gfm'
import remarkRehype from 'remark-rehype'
import rehypeStringify from 'rehype-stringify'

main()

async function main() {
  const file = await unified()
    .use(remarkParse)
    .use(remarkGfm)
    .use(remarkRehype)
    .use(rehypeStringify)
    .process('# Hi\n\n*Hello*, world!')

  console.log(String(file))
}

…running that with node example.js yields:

<h1>Hi</h1>
<p><em>Hello</em>, world!</p>

API

This package exports no identifiers. The default export is rehypeStringify.

unified().use(rehypeStringify[, options])

Add support for serializing HTML. Options are passed to hast-util-to-html.

options

Configuration (optional).

options.entities

Define how to create character references (Object, default: {}). Configuration is passed to stringify-entities. You can use the fields useNamedReferences, useShortestReferences, and omitOptionalSemicolons. You cannot use the fields escapeOnly, attribute, or subset).

options.upperDoctype

Use a <!DOCTYPE… instead of <!doctype…. Useless except for XHTML (boolean, default: false).

options.quote

Preferred quote to use ('"' or '\'', default: '"').

options.quoteSmart

Use the other quote if that results in less bytes (boolean, default: false).

options.preferUnquoted

Leave attributes unquoted if that results in less bytes (boolean, default: false).

Not used in the SVG space.

options.omitOptionalTags

Omit optional opening and closing tags (boolean, default: false). For example, in <ol><li>one</li><li>two</li></ol>, both </li> closing tags can be omitted. The first because it’s followed by another li, the last because it’s followed by nothing.

Not used in the SVG space.

options.collapseEmptyAttributes

Collapse empty attributes: get class instead of class="" (boolean, default: false).

Not used in the SVG space.

👉 Note: boolean attributes (such as hidden) are always collapsed.

options.closeSelfClosing

Close self-closing nodes with an extra slash (/): <img /> instead of <img> (boolean, default: false). See tightSelfClosing to control whether a space is used before the slash.

Not used in the SVG space.

options.closeEmptyElements

Close SVG elements without any content with slash (/) on the opening tag instead of an end tag: <circle /> instead of <circle></circle> (boolean, default: false). See tightSelfClosing to control whether a space is used before the slash.

Not used in the HTML space.

options.tightSelfClosing

Do not use an extra space when closing self-closing elements: <img/> instead of <img /> (boolean, default: false).

👉 Note: only used if closeSelfClosing: true or closeEmptyElements: true.

options.tightCommaSeparatedLists

Join known comma-separated attribute values with just a comma (,), instead of padding them on the right as well (,␠, where represents a space) (boolean, default: false).

options.tightAttributes

Join attributes together, without whitespace, if possible: get class="a b"title="c d" instead of class="a b" title="c d" to save bytes (boolean, default: false).

Not used in the SVG space.

👉 Note: intentionally creates parse errors in markup (how parse errors are handled is well defined, so this works but isn’t pretty).

options.tightDoctype

Drop unneeded spaces in doctypes: <!doctypehtml> instead of <!doctype html> to save bytes (boolean, default: false).

👉 Note: intentionally creates parse errors in markup (how parse errors are handled is well defined, so this works but isn’t pretty).

options.bogusComments

Use “bogus comments” instead of comments to save byes: <?charlie> instead of <!--charlie--> (boolean, default: false).

👉 Note: intentionally creates parse errors in markup (how parse errors are handled is well defined, so this works but isn’t pretty).

options.allowParseErrors

Do not encode characters which cause parse errors (even though they work), to save bytes (boolean, default: false).

Not used in the SVG space.

👉 Note: intentionally creates parse errors in markup (how parse errors are handled is well defined, so this works but isn’t pretty).

options.allowDangerousCharacters

Do not encode some characters which cause XSS vulnerabilities in older browsers (boolean, default: false).

⚠️ Danger: only set this if you completely trust the content.

options.allowDangerousHtml

Allow raw nodes and insert them as raw HTML. When falsey, encodes raw nodes (boolean, default: false).

⚠️ Danger: only set this if you completely trust the content.

options.space

Which space the document is in ('svg' or 'html', default: 'html').

When an <svg> element is found in the HTML space, rehype-stringify already automatically switches to and from the SVG space when entering and exiting it.

👉 Note: rehype is not an XML parser. It supports SVG as embedded in HTML. It does not support the features available in XML. Passing SVG files might break but fragments of modern SVG should be fine.

options.voids

Tag names of elements to serialize without closing tag (Array<string>, default: html-void-elements).

Not used in the SVG space.

👉 Note: It’s highly unlikely that you want to pass this. It’s only really applicable to the hast-util-to-html utility.

Syntax

HTML is serialized according to WHATWG HTML (the living standard), which is also followed by browsers such as Chrome and Firefox.

Syntax tree

The syntax tree format used in rehype is hast.

Types

This package is fully typed with TypeScript. The extra types Options are exported.

Compatibility

Projects maintained by the unified collective are compatible with all maintained versions of Node.js. As of now, that is Node.js 12.20+, 14.14+, and 16.0+. Our projects sometimes work with older versions, but this is not guaranteed.

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.

Use of rehype plugins could also open you up to other attacks. Carefully assess each plugin and the risks involved in using them.

For info on how to submit a report, see our security policy.

Contribute

See contributing.md in rehypejs/.github for ways to get started. See support.md for ways to get help.

This project has a code of conduct. By interacting with this repository, organization, or community you agree to abide by its terms.

Support this effort and give back by sponsoring on OpenCollective!

Vercel

Motif

HashiCorp

GitBook

Gatsby

Netlify

Coinbase

ThemeIsle

Expo

Boost Note

Holloway


You?

License

MIT © Titus Wormer