dom_modified.js

(function() {
  var queue = [];
  function checkQueue() {
    if (queue.any())
      queue.pop().fire("dom:modified");
  }

  var notify;
  function deferFire(element) {
    if (!queue.include(element))
      queue.push(element);

    if (notify)
      window.clearTimeout(notify);
    notify = checkQueue.defer();
  }

  function fireModifiedEvent() {
    var args = $A(arguments), proceed = args.shift(), parent = $(args.first()).up();
    var element = proceed.apply(this, args);

    if (Object.isElement(element) && element.up("html")) {
      deferFire(element);
    } else if (Object.isElement(parent) && parent.up("html")) {
      deferFire(parent);
    }

    return element;
  }

  Element.addMethods({
    insert: Element.Methods.insert.wrap(fireModifiedEvent),
    replace: Element.Methods.replace.wrap(fireModifiedEvent),
    update: Element.Methods.update.wrap(fireModifiedEvent)
  });

  document.observe("dom:loaded", function() {
    $(document.body).fire("dom:modified");
  });
})();