Fastmatter NPM

fastmatter

A fast frontmatter parser. Supports both string and stream inputs.

Usage

Given a document foo.md containing YAML frontmatter and content:

---
title: Hello, World!
tags: [ foo, bar, baz ]
---
Lorem ipsum dolor sit amet consectetur adipisicing elit.

…we can parse this document as a string, via fastmatter(string):

const fastmatter = require('fastmatter')
const fs = require('fs')

fs.readFile('foo.md', 'utf8', function (error, data) {
  if (error) {
    throw error
  }
  console.log(fastmatter(data))
  /* =>
   * {
   *   attributes: {
   *     title: 'Hello, World!',
   *     tags: [ 'foo', 'bar', 'baz' ]
   *   },
   *   body: 'Lorem ipsum dolor sit amet consectetur adipisicing elit.'
   * }
   */
})

…or as a stream, via fastmatter.stream([callback]):

const fastmatter = require('fastmatter')
const fs = require('fs')
const concat = require('concat-stream')

fs.createReadStream('foo.md').pipe(
  fastmatter.stream(function (attributes) {
    console.log(attributes)
    /* =>
     * {
     *   title: 'Hello, World!',
     *   tags: [ 'foo', 'bar', 'baz' ]
     * }
     */
    this.pipe(
      concat(function (body) {
        console.log(body.toString())
        //=> Lorem ipsum dolor sit amet consectetur adipisicing elit.
      })
    )
  })
)

callback is called with the frontmatter attributes, while the document body is simply passed through the stream. Also note that the this context of callback is the stream itself; this is useful if we want to change the flow of the stream depending on the parsed attributes.

API

const fastmatter = require('fastmatter')

fastmatter(string)

Parses the string and returns the parsed frontmatter attributes and document body.

fastmatter.stream(callback)

Calls callback with the parsed frontmatter attributes. The this context of callback is the stream itself. The document body is passed through the stream.