showdown/src/subParsers/anchors.js

/**
 * Created by Estevao on 11-01-2015.
 */

/**
 * Turn Markdown link shortcuts into XHTML <a> tags.
 */
showdown.subParser('anchors', function (text, config, globals) {
    'use strict';

    var writeAnchorTag = function (wholeMatch, m1, m2, m3, m4, m5, m6, m7) {
        if (showdown.helper.isUndefined(m7)) {
            m7 = '';
        }
        wholeMatch = m1;
        var linkText = m2,
            linkId = m3.toLowerCase(),
            url = m4,
            title = m7;

        if (!url) {
            if (!linkId) {
                // lower-case and turn embedded newlines into spaces
                linkId = linkText.toLowerCase().replace(/ ?\n/g, ' ');
            }
            url = '#' + linkId;

            if (!showdown.helper.isUndefined(globals.gUrls[linkId])) {
                url = globals.gUrls[linkId];
                if (!showdown.helper.isUndefined(globals.gTitles[linkId])) {
                    title = globals.gTitles[linkId];
                }
            }
            else {
                if (wholeMatch.search(/\(\s*\)$/m) > -1) {
                    // Special case for explicit empty url
                    url = '';
                } else {
                    return wholeMatch;
                }
            }
        }

        url = showdown.helper.escapeCharacters(url, '*_');
        var result = '<a href="' + url + '"';

        if (title !== '' && title !== null) {
            title = title.replace(/"/g, '&quot;');
            title = showdown.helper.escapeCharacters(title, '*_');
            result += ' title="' + title + '"';
        }

        result += '>' + linkText + '</a>';

        return result;
    };

    // First, handle reference-style links: [link text] [id]
    /*
     text = text.replace(/
     (							// wrap whole match in $1
     \[
     (
     (?:
     \[[^\]]*\]		// allow brackets nested one level
     |
     [^\[]			// or anything else
     )*
     )
     \]

     [ ]?					// one optional space
     (?:\n[ ]*)?				// one optional newline followed by spaces

     \[
     (.*?)					// id = $3
     \]
     )()()()()					// pad remaining backreferences
     /g,_DoAnchors_callback);
     */
    text = text.replace(/(\[((?:\[[^\]]*\]|[^\[\]])*)\][ ]?(?:\n[ ]*)?\[(.*?)\])()()()()/g, writeAnchorTag);

    //
    // Next, inline-style links: [link text](url "optional title")
    //

    /*
     text = text.replace(/
     (						// wrap whole match in $1
     \[
     (
     (?:
     \[[^\]]*\]	// allow brackets nested one level
     |
     [^\[\]]			// or anything else
     )
     )
     \]
     \(						// literal paren
     [ \t]*
     ()						// no id, so leave $3 empty
     <?(.*?)>?				// href = $4
     [ \t]*
     (						// $5
     (['"])				// quote char = $6
     (.*?)				// Title = $7
     \6					// matching quote
     [ \t]*				// ignore any spaces/tabs between closing quote and )
     )?						// title is optional
     \)
     )
     /g,writeAnchorTag);
     */
    text = text.replace(/(\[((?:\[[^\]]*\]|[^\[\]])*)\]\([ \t]*()<?(.*?(?:\(.*?\).*?)?)>?[ \t]*((['"])(.*?)\6[ \t]*)?\))/g, writeAnchorTag);

    //
    // Last, handle reference-style shortcuts: [link text]
    // These must come last in case you've also got [link test][1]
    // or [link test](/foo)
    //

    /*
     text = text.replace(/
     (		 					// wrap whole match in $1
     \[
     ([^\[\]]+)				// link text = $2; can't contain '[' or ']'
     \]
     )()()()()()					// pad rest of backreferences
     /g, writeAnchorTag);
     */
    text = text.replace(/(\[([^\[\]]+)\])()()()()()/g, writeAnchorTag);

    return text;


});