Diff for gist.github for Opera

diff_for_gist.user.js

// ==UserScript==
// @name          Diff for gists for Opera
// @include       http://gist.github.com/*
// @include       https://gist.github.com/*
// @ujs:modified  2010-09-10
// @ujs:download  http://gist.github.com/raw/227881/53ad5dff46b825ea3facd77532b57da2ab445425/diff_for_gist.user.js
// ==/UserScript==

(function(window, $, rev) {
  if (!$ || ((rev = $('#revisions li')).length < 2)) return;
  var diffSelect = function(e) {
    var me = e.target, c = $('#revisions li input:checked'), length = c.length;
    if (length > 2)
      c.each(function() { if (this != me) this.checked = false; });
    $('#diffExec').attr('disabled', (length != 2));
  },
  diffcontent, diffscript, $files = $('#files'), diffsrc = 'http://gist.github.com/105908.txt', count, maxCount, last,
  diffExec = function() {
    if (!window.Diff && !diffscript) {
      return (diffscript = $.getScript(diffsrc, diffExec));
    }
    count = 0;
    var selected = $('#revisions').find('input:checkbox:checked'),
    link = selected.map(function() {return this.value.replace(/(https?:\/\/[^\/]+\/)/, '$1raw/')}),
    desc = selected.map(function() { return $(this).parent().text().replace(/\s+/g, ' '); }),
    req = function(url,func){
      var x = new XMLHttpRequest();
      x.onload = func;
      if (url.indexOf(location.protocol) == -1) {
        url = location.protocol + url.split(':').slice(1).join(':');
      }
      x.open('GET',url,false);
      x.send(null);
      return x;
    },
    clog1,clog2,flog1,flog2,raw1,raw2,
    log = function(){
      setTimeout(function(){
        var r1 = clog1.responseText.split(/\n/)[0].split(/\s/)[1];
        var r2 = clog2.responseText.split(/\n/)[0].split(/\s/)[1];
        flog1 = req(link[0].replace(/[^\/]*$/, r1) + '/meta', function(){
          flog2 = req(link[1].replace(/[^\/]*$/, r2) + '/meta',fil);
        });
      },100);
    },
    fil = function(){
      setTimeout(function() {
        flog1 = flog1.responseText.split(/\n/);
        flog2 = flog2.responseText.split(/\n/);
        maxCount = Math.min(flog1.length, flog2.length)
        setTimeout(fil2, 100);
      }, 100);
    },
    fil2 = function() {
      var $diff = $(diffcontent = $files.find('div.file')[count *2].cloneNode(true));
      if (!last) {
        $diff.prependTo($files).hide();
      }
      else {
        $diff.insertAfter(last).hide();
      }
      last = diffcontent;
      pres = diffcontent.getElementsByTagName('pre');
      pres[0].parentNode.replaceChild(pres[0].cloneNode(false),pres[0]);
      pres[1].parentNode.replaceChild(pres[1].cloneNode(false),pres[1]);
      var r1 = flog1[count].split(/\s/);
      var r2 = flog2[count].split(/\s/);
      raw1 = req(link[0].replace(/[^\/]*$/, r1[2]) + '/' + r1[3], function(){
        raw2 = req(link[1].replace(/[^\/]*$/, r2[2]) + '/' + r2[3], dif);
      });
    },
    dif = function(){
      setTimeout(function(){
        var pre = $(pres[1]);
        var udiff = new UnifiedDiff(raw2.responseText, raw1.responseText, 4).toString();
        udiff = '--- ' + desc[1] + '\n' + '+++ ' + desc[0] + '\n' + pre.text(udiff).html();
        var len = udiff.split(/\n/).length;
        if(len < 5000) {
          udiff = udiff.replace(/^(\+.*)$/mg, '<span class="gi">$1</span>')
            .replace(/^(\-.*)$/mg, '<span class="gd">$1</span>')
            .replace(/^(\@.*)$/mg, '<span class="gu">$1</span>')
            .replace(/^(.*)\n/mg, '<div class="line">$1</div>');
          pres[0].innerHTML = Array(len-1).join(',').split(',').map(function(a,i){return '<span>'+(1+i)+'</span>'}).join('\n');
        }
        pre.html(udiff);
        $(diffcontent).slideDown('normal');
        if (count++ < maxCount && ((count*2) < $files.find('div.file').length)) {
          fil2();
        }
      },100);
    };
    clog1 = req(link[0] + '/meta',function(){
      clog2 = req(link[1] + '/meta',log);
    });
  };
  $('<input type="button" id="diffExec" value="Compare" disabled="disabled"/>')
    .appendTo('#revisions')
    .click(diffExec);
    
  rev.each(function() {
    $('<input type="checkbox" name="diff" />')
      .val($(this).find('.id').attr('href'))
      .prependTo(this)
      .click(diffSelect);
  });
})(this, this.jQuery);