markdown-it/README.md

remarkable

Markdown parser done right. Fast and easy to extend.

Live demo

• Configurable syntax! You can add new rules and even replace existing ones.
• Implements CommonMark spec + syntax extentions + sugar (URL autolinking, typographer).
• Very high speed.

Install

node.js:

npm install remarkable --save

bower:

bower install remarkable --save

CDNs for browser: jsDeliver

Usage

var Remarkable = require('remarkable');

// This values are default
var md = new Remarkable(/* "default" */, {
  html:         false,        // Enable html tags in source
  xhtmlOut:     false,        // Use '/' to close single tags (<br />)
  breaks:       false,        // Convert '\n' in paragraphs into <br>
  langPrefix:   'language-',  // CSS language prefix for fenced blocks
  linkify:      false,        // Autoconvert url-like texts to links
  typographer:  false,        // Enable smartypants and other sweet transforms

  // Highlighter function. Should return escaped html,
  // or '' if input not changed
  highlight: function (/*str, , lang*/) { return ''; }
});

console.log(md.render('# Remarkable rulezz!'));
// => <h1>Remarkable rulezz!</h1>

You can define options via set method:

var Remarkable = require('remarkable');
var md = new Remarkable('full');

md.set({
  html: true,
  breaks: true
});

Note. To acheive best performance, don't modify the Remarkable instance on the fly. If you need several configurations - create multiple instances and initialise each appropriately.

Remarkable provides presets to quickly manage active syntax rules and options. You can reset parser to strict CommonMark mode:

var Remarkable = require('remarkable');
var md = new Remarkable('commonmark');

Or you can enable everything:

var Remarkable = require('remarkable');
var md = new Remarkable('full');

By default remarkable is configured to be similar to GFM, but with disabled HTML.

Highlight fenced blocks

To highlight content of fenced block, assign function to highlight option:

var Remarkable = require('remarkable');
var hljs       = require('highlight.js') // https://highlightjs.org/

// These values are default
var md = new Remarkable({
  highlight: function (str, lang) {
    if (lang && hljs.getLanguage(lang)) {
      try {
        return hljs.highlight(lang, str).value;
      } catch (__) {}
    }

    try {
      return hljs.highlightAuto(str).value;
    } catch (__) {}

    return ''; // use external default escaping
  }
});

Syntax extentions

Enabled by default:

• Tables (GFM)
• <del> (GFM strikethrough) - ~~deleted text~~

Disabled by default:

• <ins> - ++inserted text++
• <mark> - ==marked text==

Manage rules:

var md = new Remarkable();
md.inline.ruler.enable([ 'ins', 'mark' ]);
md.block.ruler.disable([ 'table' ]);

// Enable everything
md = new Remarkable('full', {
  html: true,
  linkify: true,
  typographer: true,
});

Typographer

Though full-weight typograpic replacements are language specific, remarkable provides the most common and universal case coverage:

var Remarkable = require('remarkable');
var md = new Remarkable({ typographer: true });

// These values are default
md.typographer.set({
  singleQuotes: '‘’', // set empty to disable
  doubleQuotes: '“”', // set '«»' for russian, '„“' for deutch, empty to disable
  copyright:    true, // (c) (C) → ©
  trademark:    true, // (tm) (TM) → ™
  registered:   true, // (r) (R) → ®
  plusminus:    true, // +- → ±
  paragraph:    true, // (p) (P) -> §
  ellipsis:     true, // ... → … (also ?.... → ?.., !.... → !..)
  dupes:        true, // ???????? → ???, !!!!! → !!!, `,,` → `,`
  dashes:       true  // -- → –, --- → —
})

Of course, you can add your own rules or replace default ones with something more advanced, specific for your language.

References / Thanks

Big thanks to John MacFarlane for his work on the CommonMark spec and reference implementations. His work saved us a lot of time during this project's development.

Links:

1. https://github.com/jgm/CommonMark - reference CommonMark implementations in C & JS, also contains latest spec & online demo.
2. http://talk.commonmark.org - CommonMark forum, good place to collaborate developpers efforts.

Development / Modification

Parser consists of several responsibilities chains, filled with rules. You can reconfigure anyone as you wish. Render also can be modified and extended. See source code to understand details. Pay attention to this properties:

Remarkable.block
Remarkable.block.ruler
Remarkable.inline
Remarkable.inline.ruler
Remarkable.typographer
Remarkable.typographer.ruler
Remarkable.linkifier
Remarkable.linkifier.ruler
Remarkable.renderer
Remarkable.renderer.rules

To prettify plugins init, Remarked has .use() helper for curried calls:

var md = new Remarkable();

md.use(plugin1)
  .use(plugin2, opts)
  .use(plugin3);

Authors

• Jon Schlinkert github/jonschlinkert
• Alex Kocharin github/rlidwka
• Vitaly Puzrin github/puzrin

License

MIT