Rehype-extract-excerpt NPM

rehype-extract-excerpt

rehype plugin which attaches a document's first paragraph to the VFile.

What is this?

This package is a unified (rehype) plugin to extract the first paragraph of a document.

unified is a project that transforms content with abstract syntax trees (ASTs). rehype adds support for HTML to unified. vfile is the virtual file interface used in unified. hast is the HTML AST that rehype uses.

This is a rehype plugin that inspects hast and adds an excerpt to vfiles.

When should I use this?

This plugin is useful if you want to use the first paragraph of a markdown file as description, instead of adding a description to the frontmatter.

Install

This package is ESM only. In Node.js (version 16.0+, or 18.0+), install with npm:

npm install rehype-extract-excerpt

In Deno, with esm.sh:

import rehypeExtractExcerpt from 'https://esm.sh/rehype-extract-excerpt'

In browsers, with esm.sh:

<script type="module">
  import rehypeExtractExcerpt from 'https://esm.sh/rehype-extract-excerpt?bundle'
</script>

Use

Say our module example.js looks as follows:

import { unified } from 'unified'
import remarkParse from 'remark-parse'
import remarkRehype from 'remark-rehype'
import rehypeExtractExcerpt from 'rehype-extract-excerpt'
import rehypeStringify from 'rehype-stringify'

const file = await unified()
  .use(remarkParse)
  .use(remarkRehype)
  .use(rehypeExtractExcerpt)
  .use(rehypeStringify).process(`# Test heading h1

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat.

## Test heading h2

Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.`)

console.log(file.data)
console.log(String(file))

…now running node example.js yields:

{
  excerpt: 'Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad...'
}

API

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

`unified().use(rehypeExtractExcerpt, options?)`

Attach a document's first paragraph as file metadata. The result is stored on file.data.excerpt. If the document does not contain a paragraph, data.extract value will be undefined.

`options`

Configuration (optional).

`options.name`

The var name of the vFile.data export. (string, default: 'excerpt').

`options.maxLength`

The character length to truncate the excerpt. (number, default: 140).

`options.ellipsis`

The ellipsis to add to the excerpt. Use '' to disable. (string, default: '...').

`options.wordBoundaries`

Truncate the excerpt at word boundary. (boolean, default: true).

`options.tagName`

The HTML tag name to extract excerpt from. (string, default: 'p').

Types

This package is fully typed with TypeScript. The additional type RehypeExtractExcerptOptions is exported.

Security

Use of rehype-extract-excerpt is safe.

@stefanprobst/rehype-extract-toc — plugin which attaches a document's table of contents to the VFile
@stefanprobst/remark-excerpt — transformer plugin to extract an excerpt