Linkify Plus

// ==UserScript==
// @name        Linkify Plus
// @version     2.1.4
// @namespace   http://arantius.com/misc/greasemonkey/
// @description Turn plain text URLs into links.    Supports http, https, ftp, email addresses.
// @include     http*
// @exclude     http://www.google.tld/search*
// @exclude     https://www.google.tld/search*
// @exclude     http://music.google.com/*
// @exclude     https://music.google.com/*
// @exclude     http://mail.google.com/*
// @exclude     https://mail.google.com/*
// @exclude     http://docs.google.com/*
// @exclude     https://docs.google.com/*
// @exclude     http://mxr.mozilla.org/*
// ==/UserScript==
//
// Copyright (c) 2011, Anthony Lieuallen
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
//   this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
//   this list of conditions and the following disclaimer in the documentation
//   and/or other materials provided with the distribution.
// * Neither the name of Anthony Lieuallen nor the names of its contributors
//   may be used to endorse or promote products derived from this software
//   without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//

/*******************************************************************************
Loosely based on the Linkify script located at:
  http://downloads.mozdev.org/greasemonkey/linkify.user.js

Version history:
 Version 2.1.4 (Aug 12, 2012):
  - Bug fix for when (only some) nodes have been removed from the document.
 Version 2.1.3 (Oct 24, 2011):
  - More excludes.
 Version 2.1.2:
  - Some bug fixes.
 Version 2.1.1:
  - Ignore certain "highlighter" script containers.
 Version 2.1:
  - Rewrite the regular expression to be more readable.
  - Fix trailing "." characters.
 Version 2.0.3:
  - Fix infinite recursion on X(HT)ML pages.
 Version 2.0.2:
  - Limit @include, for greater site/plugin compatibility.
 Version 2.0.1:
  - Fix aberrant 'mailto:' where it does not belong.
 Version 2.0:
  - Apply incrementally, so the browser does not hang on large pages.
  - Continually apply to new content added to the page (i.e. AJAX).
 Version 1.1.4:
  - Basic "don't screw up xml pretty printing" exception case
 Version 1.1.3:
  - Include "+" in the username of email addresses.
 Version 1.1.2:
  - Include "." in the username of email addresses.
 Version 1.1:
  - Fixed a big that caused the first link in a piece of text to
    be skipped (i.e. not linkified).
*******************************************************************************/

var notInTags = [
      'a', 'code', 'head', 'noscript', 'option', 'script', 'style',
      'title', 'textarea'];
var textNodeXpath =
    ".//text()[not(ancestor::"+notInTags.join(') and not(ancestor::')+")]";
// Built based on:
//  - http://en.wikipedia.org/wiki/URI_scheme
//  - http://www.regular-expressions.info/regexbuddy/email.html
var urlRE = new RegExp(
    '('
    // leading scheme:// or "www."
    + '\\b([a-z][-a-z0-9+.]+://|www\\.)'
    // everything until non-URL character
    + '[^\\s\'"<>()]+'
    + '|'
    // email
    + '\\b[a-z0-9._%+-]+@[a-z0-9.-]+\\.[a-z]{2,4}\\b'
    + ')', 'gi');
var queue = [];

/******************************************************************************/

linkifyContainer(document.body);
document.body.addEventListener('DOMNodeInserted', function(event) {
    linkifyContainer(event.target);
}, false);

/******************************************************************************/

function linkifyContainer(container) {
    // Prevent infinite recursion, in case X(HT)ML documents with namespaces
    // break the XPath's attempt to do so.  (Don't evaluate spans we put our
    // classname into.)
    if (container.className && container.className.match(/\blinkifyplus\b/)) {
      return;
    }

    var xpathResult = document.evaluate(
          textNodeXpath, container, null,
          XPathResult.UNORDERED_NODE_SNAPSHOT_TYPE, null);

    var i = 0;
    function continuation() {
        var node = null, counter = 0;
        while (node = xpathResult.snapshotItem(i++)) {
          var parent = node.parentNode;
          if (!parent) continue;

          // Skip styled <pre> -- often highlighted by script.
          if ('PRE' == parent.tagName && parent.className) continue;

            linkifyTextNode(node);

            if (++counter > 50) {
                return setTimeout(continuation, 0);
            }
        }
    }
    setTimeout(continuation, 0);
}

function linkifyTextNode(node) {
    var i, l, m;
    var txt = node.textContent;
    var span = null;
    var p = 0;
    while (m = urlRE.exec(txt)) {
        if (null == span) {
            // Create a span to hold the new text with links in it.
            span = document.createElement('span');
            span.className = 'linkifyplus';
        }

        //get the link without trailing dots
        l = m[0].replace(/\.*$/, '');
        var lLen = l.length;
        //put in text up to the link
        span.appendChild(document.createTextNode(txt.substring(p, m.index)));
        //create a link and put it in the span
        a = document.createElement('a');
        a.className = 'linkifyplus';
        a.appendChild(document.createTextNode(l));
        if (l.indexOf(":/") < 0) {
            if (l.indexOf("@") > 0) {
                l = "mailto:" + l;
            } else {
                l = "http://" + l;
          }
        }
        a.setAttribute('href', l);
        span.appendChild(a);
        //track insertion point
        p = m.index+lLen;
    }
    if (span) {
        //take the text after the last link
        span.appendChild(document.createTextNode(txt.substring(p, txt.length)));
        //replace the original text with the new span
        try {
            node.parentNode.replaceChild(span, node);
        } catch (e) {
            console.error(e);
            console.log(node);
        }
    }
}