marked/USAGE_EXTENSIBILITY.md

Extending Marked

To champion the single-reponsibility and open/closed prinicples, we have tried to make it relatively painless to extend marked. If you are looking to add custom functionality, this is the place to start.

• The renderer
• The lexer
• The parser

The renderer

The renderer is...

Example: Overriding default heading token by adding an embedded anchor tag like on GitHub.

// Create reference instance
var myMarked = require('marked');

// Get reference
var renderer = new myMarked.Renderer();

// Override function
renderer.heading = function (text, level) {
  var escapedText = text.toLowerCase().replace(/[^\w]+/g, '-');

  return `<h${level}>
  			<a name="'${escapedText}'" class="anchor" href="#${escapedText}">
  				<span class="header-link"></span>
  			</a>
  			${text}
		</h${level}>`;
};

// Run marked
console.log(marked('# heading+', { renderer: renderer }));

Output:

<h1>
  <a name="heading-" class="anchor" href="#heading-">
    <span class="header-link"></span>
  </a>
  heading+
</h1>

Block level renderer methods

• code(string code, string language)
• blockquote(string quote)
• html(string html)
• heading(string text, number level)
• hr()
• list(string body, boolean ordered)
• listitem(string text)
• paragraph(string text)
• table(string header, string body)
• tablerow(string content)
• tablecell(string content, object flags)

flags has the following properties:

{
    header: true || false,
    align: 'center' || 'left' || 'right'
}

Inline level renderer methods

• strong(string text)
• em(string text)
• codespan(string code)
• br()
• del(string text)
• link(string href, string title, string text)
• image(string href, string title, string text)
• text(string text)

The lexer

The lexer is...

The parser

The parser is...

---

Access to lexer and parser

You also have direct access to the lexer and parser if you so desire.

var tokens = marked.lexer(text, options);
console.log(marked.parser(tokens));

var lexer = new marked.Lexer(options);
var tokens = lexer.lex(text);
console.log(tokens);
console.log(lexer.rules);

Pro level

You also have direct access to the lexer and parser if you so desire.

var tokens = marked.lexer(text, options);
console.log(marked.parser(tokens));

var lexer = new marked.Lexer(options);
var tokens = lexer.lex(text);
console.log(tokens);
console.log(lexer.rules);

$ node
> require('marked').lexer('> i am using marked.')
[ { type: 'blockquote_start' },
  { type: 'paragraph',
    text: 'i am using marked.' },
  { type: 'blockquote_end' },
  links: {} ]