hast utility to parse the tree and semistandard raw
nodes (strings of
HTML) again, keeping positional info okay.
- What is this?
- When should I use this?
- Install
- Use
- API
- Types
- Compatibility
- Security
- Related
- Contribute
- License
This package is a utility to parse a document again.
It passes each node and embedded raw HTML through an HTML parser
(parse5
), to recreate a tree exactly as how a browser would parse
it, while keeping the original data and positional info intact.
This utility is particularly useful when coming from markdown and wanting to
support HTML embedded inside that markdown (which requires passing
allowDangerousHtml: true
to mdast-util-to-hast
).
Markdown dictates how, say, a list item or emphasis can be parsed.
We can use that to turn the markdown syntax tree into an HTML syntax tree.
But markdown also dictates that things that look like HTML, are passed through
untouched, even when it just looks like XML but doesn’t really make sense, so we
can’t normally use these strings of “HTML” to create an HTML syntax tree.
This utility can.
It can be used to take those strings of HTML and include them into the syntax
tree as actual nodes.
If your final result is HTML and you trust content, then “strings” are fine
(you can pass allowDangerousHtml: true
to hast-util-to-html
, which passes
HTML through untouched).
But there are two main cases where a proper syntax tree is preferred:
- hast utilities need a proper syntax tree as they operate on actual nodes to inspect or transform things, they can’t operate on strings of HTML
- other output formats (React, MDX, etc) need actual nodes and can’t handle strings of HTML
The plugin rehype-raw
wraps this utility at a higher-level
(easier) abstraction.
This package is ESM only. In Node.js (version 14.14+ and 16.0+), install with npm:
npm install hast-util-raw
In Deno with esm.sh
:
import {raw} from 'https://esm.sh/hast-util-raw@8'
In browsers with esm.sh
:
<script type="module">
import {raw} from 'https://esm.sh/hast-util-raw@8?bundle'
</script>
import {h} from 'hastscript'
import {raw} from 'hast-util-raw'
const tree = h('div', [h('h1', ['Foo ', h('h2', 'Bar'), ' Baz'])])
const reformatted = raw(tree)
console.log(reformatted)
Yields:
{ type: 'element',
tagName: 'div',
properties: {},
children:
[ { type: 'element',
tagName: 'h1',
properties: {},
children: [Object] },
{ type: 'element',
tagName: 'h2',
properties: {},
children: [Object] },
{ type: 'text', value: ' Baz' } ] }
This package exports the identifier raw
.
There is no default export.
Pass a hast tree through an HTML parser, which will fix nesting, and turn raw nodes into actual nodes.
Parsed again tree (Node
).
Configuration (TypeScript type).
passThrough
(Array<string>
, optional) — list of custom hast node types to pass through (keep). If the passed through nodes have children, those children are expected to be hast and will be handled by this utilityfile
(VFile
, optional) — corresponding virtual file representing the input document
Interface of semistandard Raw
nodes (TypeScript type).
export interface Raw extends Literal {
type: 'raw'
}
This package is fully typed with TypeScript.
It exports the additional types Options
and Raw
.
The types also register the Raw
node type with @types/hast
.
If you’re working with the syntax tree, make sure to import this utility
somewhere in your types, as that registers the new node types in the tree.
/**
* @typedef {import('hast-util-raw')}
*/
import {visit} from 'unist-util-visit'
/** @type {import('hast').Root} */
const tree = getHastNodeSomeHow()
visit(tree, (node) => {
// `node` can now be a `raw` node.
})
Projects maintained by the unified collective are compatible with all maintained versions of Node.js. As of now, that is Node.js 14.14+ and 16.0+. Our projects sometimes work with older versions, but this is not guaranteed.
Use of hast-util-raw
can open you up to a cross-site scripting (XSS)
attack as raw
nodes are unsafe.
The following example shows how a raw node is used to inject a script that runs
when loaded in a browser.
raw(u('root', [u('raw', '<script>alert(1)</script>')]))
Yields:
<script>alert(1)</script>
Either do not use this utility in combination with user input, or use
hast-util-santize
.
mdast-util-to-hast
— transform mdast to hastrehype-raw
— rehype plugin
See contributing.md
in syntax-tree/.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.