What is front-matter?
The front-matter npm package is used to parse YAML or JSON front matter from strings, typically used in markdown files. This is useful for extracting metadata from content files.
What are front-matter's main functionalities?
Parsing Front Matter
This feature allows you to parse a string containing front matter and extract the metadata and content separately.
const frontMatter = require('front-matter');
const content = '---\ntitle: Hello World\ndate: 2023-10-01\n---\nThis is the content of the file.';
const parsed = frontMatter(content);
console.log(parsed.attributes); // { title: 'Hello World', date: '2023-10-01' }
console.log(parsed.body); // 'This is the content of the file.'
Custom Delimiters
This feature allows you to specify custom delimiters for the front matter, which is useful if your front matter is not delimited by the default '---'.
const frontMatter = require('front-matter');
const content = '+++\ntitle: Hello World\ndate: 2023-10-01\n+++\nThis is the content of the file.';
const options = { delimiters: '+++' };
const parsed = frontMatter(content, options);
console.log(parsed.attributes); // { title: 'Hello World', date: '2023-10-01' }
console.log(parsed.body); // 'This is the content of the file.'
Other packages similar to front-matter
gray-matter
gray-matter is a popular package for parsing front matter from strings. It supports YAML, JSON, and TOML front matter, and offers more features like custom engines and stringifying parsed data back to front matter format. It is more feature-rich compared to front-matter.
front-matter
This modules does not do any IO (file loading or reading), only extracting yaml front matter from strings.
This concept that was originally introduced to me through the jeykll blogging system and is pretty useful where you want to be able to easily add meta-data to content without the need for a database. YAML is extracted from the the top of a file between matching separators of "---" or "= yaml =".
Install
With npm do:
npm install front-matter
Example
So you have a file example.md
:
---
title: Just hack'n
description: Nothing to see here
---
This is some text about some stuff that happened sometime ago
NOTE: As of front-matter@2.0.0
valid front matter is considered to have
the starting separator on the first line.
Then you can do this:
var fs = require('fs')
, fm = require('front-matter')
fs.readFile('./example.md', 'utf8', function(err, data){
if (err) throw err
var content = fm(data)
console.log(content)
})
And end up with an object like this:
{ attributes: { title: 'Just hack\'n'
, description: 'Nothing to see here'
}
, body: 'This is some text about some stuff that happened sometime ago'
}
Methods
var fm = require('front-matter')
fm(string)
Return a content
object with two properties:
content.attributes
contains the extracted yaml attributes in json formcontent.body
contains the string contents below the yaml separators
fm.test(string)
Check if a string contains a front matter header of "---" or "= yaml =". Primarily used internally but is useful outside of the module.
Returns true
or false
fm.test(string) #=> true || false
Contributing
front-matter is an OPEN Source Project so please help out by reporting bugs or forking and opening pull requests when possible.
Contributors
This module is awesome because of all the folks who helped out:
LICENSE (MIT)
Copyright (c) Jason Campbell ("Author")
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.