Hast-util-from-dom NPM

hast-util-from-dom

hast utility to transform from a DOM tree.

What is this?

This package is a utility that takes a DOM tree (from the actual DOM or from things like jsdom) as input and turns it into a hast (HTML) syntax tree.

When should I use this?

You can use this project when you want to use hast in browsers. This package is very small, but it does so by:

…not providing positional information
…potentially yielding varying results in different (especially older) browsers

The hast utility hast-util-to-dom does the inverse of this utility. It turns hast into a DOM tree.

The rehype plugin rehype-dom-parse wraps this utility to parse HTML with DOM APIs.

Install

This package is ESM only. In Node.js (version 16+), install with npm:

npm install hast-util-from-dom

In Deno with esm.sh:

import {fromDom} from 'https://esm.sh/hast-util-from-dom@5'

In browsers with esm.sh:

<script type="module">
  import {fromDom} from 'https://esm.sh/hast-util-from-dom@5?bundle'
</script>

Use

Say our page example.html looks as follows:

<!doctype html>
<title>Example</title>
<body>
  <main>
    <h1>Hi</h1>
    <p><em>Hello</em>, world!</p>
  </main>
  <script type="module">
    import {fromDom} from 'https://esm.sh/hast-util-from-dom@4?bundle'

    const hast = fromDom(document.querySelector('main'))

    console.log(hast)
  </script>

Now running open example.html prints the following to the console:

{type: "element", tagName: "main", properties: {}, children: Array}

API

This package exports the identifier fromDom. There is no default export.

`fromDom(tree, options?)`

Transform a DOM tree to a hast tree.

Parameters

tree (DomNode) — DOM tree to transform
options (Options, optional) — configuration

Returns

Equivalent hast node (HastNode).

`AfterTransform`

Callback called when each node is transformed (TypeScript type).

Parameters

domNode (DomNode) — DOM node that was handled
hastNode (HastNode) — corresponding hast node

Returns

Nothing.

`Options`

Configuration (TypeScript type).

Fields

afterTransform (AfterTransform, optional) — callback called when each node is transformed

Returns

HastNode.

Types

This package is fully typed with TypeScript. It exports the additional types AfterTransform and Options.

Compatibility

Projects maintained by the unified collective are compatible with maintained versions of Node.js.

When we cut a new major release, we drop support for unmaintained versions of Node. This means we try to keep the current release line, hast-util-from-dom@^5, compatible with Node.js 16.