remark-extract-frontmatter

remark-extract-frontmatter

Remark plugin to store front matter from markdown.

Install

npm install --save remark-extract-frontmatter

Usage

If we have some markdown using yaml frontmatter, example.md

---
title: Example
list:
  - one
  - 0
  - false
---

# Other markdown

and

const extract = require('remark-extract-frontmatter')
const frontmatter = require('remark-frontmatter')
const compiler = require('remark-stringify')
const report = require('vfile-reporter')
const parser = require('remark-parse')
const toVfile = require('to-vfile')
const unified = require('unified')
const yaml = require('yaml').parse

unified()
  .use(parser)
  .use(compiler)
  .use(frontmatter)
  .use(extract, { yaml: yaml })
  .process(toVfile.readSync('./example.md'), function (err, file) {
    console.error(report(err || file))
    console.log(file.toString())
    console.log(file.data)
  })

will output

./example.md: no issues found
---
title: 'Example'
list:
  - one
  - 0
  - false
---

# Other markdown

{ title: 'Example', list: [ 'one', 0, false ] }

Options

Options[parser]

Type: Function

Default: null

Specify the function (value) to use when parsing a frontmatter type (key). For example for yaml, options could be { yaml: require('yaml').parse }, or for toml { toml: require('toml').parse }. If no parsing function is set then this plugin will do nothing by default.

name

Type: String

Default: null

Specify a key to store frontmatter in for example, { name: 'frontmatter' } will store any parsed frontmatter as data: { frontmatter: { ... } }. By default the parsed frontmatter is merged into the data object.

Example:

unified()
  .use(parser)
  .use(compiler)
  .use(frontmatter, [ 'toml' ])
  .use(extract, { name: 'frontmatter', toml: toml.parse })
  .process('+++\ntitle: "Example"\n+++', function (err, file) {
    console.log(file.data)
  })

will output

{ frontmatter: { title: 'Example' } }

throws

Type: Boolean

Default: false

Specify if when an error parsing frontmatter occurs, to fail and throw error using VFile.fail or continue and set a warning using VFile.message.

remove

Type: Boolean

Default: false

Indicate if we should remove parsed frontmatter from the VFile. The default behavior is to leave the parsed content in the VFile

License

MIT © Paul Zimmer