load_it.js

(function() {

  var script = null;

  // load jQuery if it's not already there
  if (typeof jQuery == 'undefined') {
    script = document.createElement('script');
    script.setAttribute('src', 'http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.js');
    document.getElementsByTagName('head')[0].appendChild(script);
  }

  // once jQuery is loaded, start polling for stylesheet changes
  setTimeout(startPollingIfJQueryIsLoaded, 300);

  function startPollingIfJQueryIsLoaded() {
    if (typeof jQuery == 'undefined') {
      return setTimeout(startPollingIfJQueryIsLoaded, 300);
    } else {

      if (script) jQuery.noConflict();

      (function($) {

        var initialized = null;

        $.autoUpdateStylesheets = function(toggle) {
          var linkElements = $('head link[rel=stylesheet]'), index = -1;

          if (!initialized) {
            normalizeQueryStrings();
            initialized = true;
          }

          switch(toggle) {
            case 'disable':
              stop();
              break;
            case 'toggle':
            case true:
              $.autoUpdateStylesheetsTimeout ? stop() : start();
              break;
            default:
              start();
          }

          function stop() {
            showMessage('Stylesheets are now frozen.');
            if ($.autoUpdateStylesheetsTimeout) clearTimeout($.autoUpdateStylesheetsTimeout);
            $.autoUpdateStylesheetsTimeout = false;
          }

          function start() {
            showMessage('Stylesheet changes will be reflected in real-time.');
            if (!$.autoUpdateStylesheetsTimeout) $.autoUpdateStylesheetsTimeout = setTimeout(compareNextStyleSheet, 300);
          }

          function compareNextStyleSheet() {
            if (!$.autoUpdateStylesheetsTimeout) return;

            var link = getNextLinkElement(),
                url = link.href.replace(/timestamp=\d+/, 'timestamp=' + new Date().getTime());

            $.ajax({
              url: url,
              success: function(data) { 
                if (data != $(link).data('cachedData')) {
                  $(link).data('cachedData', data).attr('href', url);
                }
              }, 
              complete: function() {
                $.autoUpdateStylesheetsTimeout = setTimeout(compareNextStyleSheet, 300);
              }
            });
          }

          function getNextLinkElement() {
            index = (index + 1) % linkElements.length;
            return linkElements[index];
          }

          function normalizeQueryStrings() {
            linkElements.each(function(i, link) {
              var url = link.href;
              if (url.indexOf('?') == -1) url += '?';
              url += '&timestamp=0';
              $(link).attr('href', url);
            });
          }

          function showMessage(message) {
            var messageContainer = $('<div style="position: fixed; top: 0; padding: 15px 0; width: 100%; text-align: center;" />');
            messageContainer.append('<span style="border: 1px solid #333; padding: 5px 10px; background: #cec; font-size: 14px" />');
            messageContainer.children().html(message);

            $('body').prepend(messageContainer);

            setTimeout(function() {
              messageContainer.fadeOut('slow', function() { $(this).remove() });
            }, 2500);
          }

        }

      })(jQuery);

      jQuery.autoUpdateStylesheets('toggle');

    }
  }

})();