markdown-it-github-headings
v2.0.1
Published
Add GitHub style anchor tags to headers
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5,768
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markdown-it-github-headings
Add GitHub style anchor tags to headers
Install
npm install markdown-it-github-headings
Usage
var md = require('markdown-it')()
.use(require('markdown-it-github-headings'), options)
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.