unified

Project: micromark/micromark-extension-frontmatter

Package: micromark-extension-frontmatter@1.0.0

  1. Dependents: 3
  2. micromark extension to support frontmatter (YAML, TOML, etc)
  1. unified 173
  2. markdown 139
  3. micromark 34
  4. gfm 20
  5. micromark-extension 16
  6. frontmatter 6
  7. yaml 6
  8. toml 3

micromark-extension-frontmatter

Build Coverage Downloads Size Sponsors Backers Chat

micromark extension to support frontmatter (YAML, TOML, etc).

As there is no spec for frontmatter in markdown, this extension follows how YAML frontmatter works on github.com. For the HTML part, instead of rendering YAML, it is ignored. Other types of frontmatter can be parsed, which will by default also work the same as on github.com.

This package provides the low-level modules for integrating with the micromark tokenizer and the micromark HTML compiler.

When to use this

If you’re using micromark or mdast-util-from-markdown, use this package. Alternatively, if you’re using remark, use remark-frontmatter.

Install

This package is ESM only: Node 12+ is needed to use it and it must be imported instead of required.

npm:

npm install micromark-extension-frontmatter

Use

import {micromark} from 'micromark'
import {frontmatter, frontmatterHtml} from 'micromark-extension-frontmatter'

const output = micromark('---\na: b\n---\n# c', {
  extensions: [frontmatter()],
  htmlExtensions: [frontmatterHtml()]
})

console.log(output)

Yields:

<h1>c</h1>

API

This package exports the following identifiers: frontmatter, frontmatterHtml. There is no default export.

The export map supports the endorsed development condition. Run node --conditions development module.js to get instrumented dev code. Without this condition, production code is loaded.

frontmatter(options?)

frontmatterHtml(options?)

Note: syntax is the default export of this module, html is available at micromark-extension-frontmatter/html.

Support frontmatter (YAML, TOML, and more).

Two functions that can be called with options to get an extension for micromark to parse frontmatter (can be passed in extensions) and one to compile (ignore) them (can be passed in htmlExtensions).

options

One preset or Matter, or an array of them, defining all the supported frontmatters (default: 'yaml').

preset

Either 'yaml' or 'toml':

Matter

An object with a type and either a marker or a fence:

Example

For {type: 'yaml', marker: '-'}:

---
key: value
---

For {type: 'custom', marker: {open: '<', close: '>'}}:

<<<
data
>>>

For {type: 'custom', fence: '+=+=+=+'}:

+=+=+=+
data
+=+=+=+

For {type: 'json', fence: {open: '{', close: '}'}}:

{
  "key": "value"
}

Contribute

See contributing.md in micromark/.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.

License

MIT © Titus Wormer