@gerhobbelt/markdown-it

Markdown-it - modern pluggable markdown parser.

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10Mar 5, 2021Oct 20, 2015Minified + gzip package size for @gerhobbelt/markdown-it in KB

Readme

markdown-it

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Markdown parser done right. Fast and easy to extend.

Live demo

  • Follows the CommonMark spec + adds syntax extensions & sugar (URL autolinking, typographer).
  • Configurable syntax! You can add new rules and even replace existing ones.
  • High speed.
  • Safe by default.
  • Community-written plugins and other packages on npm.

Table of content

Install

node.js:

npm install markdown-it

browser (CDN):

Usage examples

See also:

Simple

// node.js, "classic" way:
const MarkdownIt = require('markdown-it'),
    md = new MarkdownIt();
let result = md.render('# markdown-it rulezz!');

// node.js, the same, but with sugar:
const md = require('markdown-it')();
let result = md.render('# markdown-it rulezz!');

// browser without AMD, added to "window" on script load
// Note, there is no dash in "markdownit".
const md = window.markdownit();
let result = md.render('# markdown-it rulezz!');

// ES Module, React, TypeScript
import MarkdownIt from 'markdown-it';
const md = new MarkdownIt();
// options and rules (see below)
const md = new MarkdownIt({ breaks: true }).disable('image');

Single line rendering, without paragraph wrap:

const md = require('markdown-it')();
let result = md.renderInline('__markdown-it__ rulezz!');

Init with presets and options

(*) presets define combinations of active rules and options. Can be "commonmark", "zero" or "default" (if skipped). See API docs for more details.

// commonmark mode
const md = require('markdown-it')('commonmark');

// default mode
const md = require('markdown-it')();

// enable everything
const md = require('markdown-it')({
  html: true,
  linkify: true,
  typographer: true
});

// full options list (defaults)
const md = require('markdown-it')({
  html:         false,        // Enable HTML tags in source
  xhtmlOut:     false,        // Use '/' to close single tags (<br />).
                              // This is only for full CommonMark compatibility.
  breaks:       false,        // Convert '\n' in paragraphs into <br>
  langPrefix:   'language-',  // CSS language prefix for fenced blocks. Can be
                              // useful for external highlighters.
  linkify:      false,        // Autoconvert URL-like text to links

  // highSecurity:
  // - false:           lower protection against XSS/Unicode-Homologue/etc. attacks via the input MarkDown.
  //                    This setting assumes you own or at least trust the Markdown
  //                    being fed to MarkDonw-It. The result is a nicer render.
  // - true (default):  maximum protection against XSS/Unicode-Homologue/etc. attacks via the input MarkDown.
  //                    This is the default setting and assumes you have no control or absolute trust in the Markdown
  //                    being fed to MarkDonw-It. Use this setting when using markdown-it as part of a forum or other
  //                    website where more-or-less arbitrary users can enter and feed any MarkDown to markdown-it.
  //
  // See https://en.wikipedia.org/wiki/Internationalized_domain_name for details on homograph attacks, for example.
  highSecurity: true,

  // Enable some language-neutral replacement + quotes beautification
  // For the full list of replacements, see https://github.com/markdown-it/markdown-it/blob/master/lib/rules_core/replacements.js
  typographer:  false,

  // Double + single quotes replacement pairs, when typographer enabled,
  // and smartquotes on. Could be either a String or an Array.
  //
  // For example, you can use '«»„“' for Russian, '„“‚‘' for German,
  // and ['«\xA0', '\xA0»', '‹\xA0', '\xA0›'] for French (including nbsp).
  quotes: '“”‘’',

  // Highlighter function. Should return escaped HTML,
  // or '' if the source string is not changed and should be escaped externally.
  // If result starts with <pre... internal wrapper is skipped.
  highlight: function (str, lang, attrs) { return ''; },
  
  // Configure default attributes for given tags
  default_attributes:  { 'a': [['rel', 'nofollow']] }
});

Plugins load

var md = require('markdown-it')()
            .use(plugin1)
            .use(plugin2, opts, ...)
            .use(plugin3);

Syntax highlighting

Apply syntax highlighting to fenced code blocks with the highlight option:

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

// Actual default values
var md = require('markdown-it')({
  highlight: function (str, lang, attrs) {
    if (lang && hljs.getLanguage(lang)) {
      try {
        return hljs.highlight(lang, str).value;
      } catch (__) {}
    }

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

Or with full wrapper override (if you need assign class to <pre>):

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

// Actual default values
var md = require('markdown-it')({
  highlight: function (str, lang, attrs) {
    if (lang && hljs.getLanguage(lang)) {
      try {
        return '<pre class="hljs"><code>' +
               hljs.highlight(lang, str, true).value +
               '</code></pre>';
      } catch (__) {}
    }

    return '<pre class="hljs"><code>' + md.utils.escapeHtml(str) + '</code></pre>';
  }
});

Linkify

linkify: true uses linkify-it. To configure linkify-it, access the linkify instance through md.linkify:

md.linkify.set({ fuzzyEmail: false });  // disables converting email to link

API

API documentation

If you are going to write plugins - take a look at Development info.

Syntax extensions

Embedded (enabled by default):

Via plugins:

Manage rules

By default all rules are enabled, but can be restricted by options. On plugin load all its rules are enabled automatically.

// Activate/deactivate rules, with currying
var md = require('markdown-it')()
            .disable([ 'link', 'image' ])
            .enable([ 'link' ])
            .enable('image');

// Enable everything
md = require('markdown-it')({
  html: true,
  linkify: true,
  typographer: true,
});

You can find all rules in sources: parser_core.js, parser_block, parser_inline.

Benchmark

Here is the result of readme parse at MB Pro Retina 2013 (2.4 GHz):

make benchmark-deps
benchmark/benchmark.js readme

Selected samples: (1 of 28)
 > README

Sample: README.md (7774 bytes)
 > commonmark-reference x 1,222 ops/sec ±0.96% (97 runs sampled)
 > current x 743 ops/sec ±0.84% (97 runs sampled)
 > current-commonmark x 1,568 ops/sec ±0.84% (98 runs sampled)
 > marked x 1,587 ops/sec ±4.31% (93 runs sampled)

Note. CommonMark version runs with simplified link normalizers for more "honest" compare. Difference is ~ 1.5x.

As you can see, markdown-it doesn't pay with speed for it's flexibility. Slowdown of "full" version caused by additional features not available in other implementations.

markdown-it for enterprise

Available as part of the Tidelift Subscription.

The maintainers of markdown-it and thousands of other packages are working with Tidelift to deliver commercial support and maintenance for the open source dependencies you use to build your applications. Save time, reduce risk, and improve code health, while paying the maintainers of the exact dependencies you use. Learn more.

Authors

markdown-it is the result of the decision of the authors who contributed to 99% of the Remarkable code to move to a project with the same authorship but new leadership (Vitaly and Alex). It's not a fork.

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.

Related Links:

Ports

If you find any bugs or have a feature request, please open an issue on github!

The npm package download data comes from npm's download counts api and package details come from npms.io.