@gerhobbelt/markdown-it-github-headings v2.0.0-2
markdown-it-github-headings
Add GitHub style anchor tags to headers
Install
npm install --save @gerhobbelt/markdown-it-github-headings
Usage
var md = require('@gerhobbelt/markdown-it')()
.use(require('@gerhobbelt/markdown-it-github-headings'), options)
md.render('# hello')
Options and Defaults
The defaults will make the heading anchors behave as close to how GitHub behaves as possible.
Name | Description | Default |
---|---|---|
className | name of the class that will be added to the anchor tag | anchor |
prefixHeadingIds | add a prefix to each heading ID. (see security note below) | true |
prefix | if prefixHeadingIds is true, use this string to prefix each ID. | user-content- |
enableHeadingLinkIcons | Adds the icon next to each heading | true |
linkIcon | If enableHeadingLinkIcons is true, use this to supply a custom icon (or anything really) | |
resetSlugger | reset the slugger counter between .render calls for duplicate headers. (See tests for example) | true |
Why should I prefix heading IDs?
When using user generated content, its possible to run into DOM Clobbering when heading IDs are generated. Since IDs are used by JavaScript and CSS, a user could craft a page that breaks functionality or styles. A good way to avoid clobbering is to add a prefix to every generated ID to ensure they cannot overlap with existing IDs.
If you have full control over the content, there is less of a risk, but be aware that strange bugs related to DOM Clobbering are still possible!
For more information, here are some good resources on the topic:
- User-generated content and DOM clobbering
- In the DOM, no one will hear you scream
- A discussion about GitHub implementation
- An open issue on markdown-it repo
But the prefixes make links look real gross.
One solution is to write some client side JavaScript to force non-prefixed hashes to jump to prefixed anchors. This is how its handled on GitHub and npmjs.com.
Check out marky-deep-links for an example (works great with browserify or webpack).
Contributing
Contributions welcome! Please read the contributing guidelines first.