1 document.addEventListener("DOMContentLoaded", function() {
2   console.log("Init: 1");
3   DOES_NOT_EXIST++; // error
4 }, false);
5
6 document.addEventListener("DOMContentLoaded", function() {
7   console.log("Init: 2");
8 }, false);

1 $(document).ready(function() {
2   console.log("Init: 1");
3   DOES_NOT_EXIST++; // error
4 });
5
6 $(document).ready(function() {
7   console.log("Init: 2");
8 });

1 YAHOO.util.Event.onDOMReady(function() {
2   console.log("Init: 1");
3   DOES_NOT_EXIST++; // this will throw an error
4 });
5
6 YAHOO.util.Event.onDOMReady(function() {
7   console.log("Init: 2");
8 });

 1 var currentHandler;
 2
 3 if (document.addEventListener) {
 4   document.addEventListener("fakeEvents", function() {
 5     // execute the callback
 6     currentHandler();
 7   }, false);
 8
 9   var dispatchFakeEvent = function() {
10     var fakeEvent = document.createEvent("UIEvents");
11     fakeEvent.initEvent("fakeEvents", false, false);
12     document.dispatchEvent(fakeEvent);
13   };
14 } else { // MSIE
15
16   document.documentElement.fakeEvents = 0; // an expando property
17
18   document.documentElement.attachEvent("onpropertychange", function(event) {
19     if (event.propertyName == "fakeEvents") {
20       // execute the callback
21       currentHandler();
22     }
23   });
24
25   dispatchFakeEvent = function(handler) {
26     // fire the propertychange event
27     document.documentElement.fakeEvents++;
28   };
29 }
30
31 var onLoadHandlers = [];
32 function addOnLoad(handler) {
33   onLoadHandlers.push(handler);
34 };
35
36 window.onload = function() {
37   for (var i = 0; i < onLoadHandlers.length; i++) {
38     currentHandler = onLoadHandlers[i];
39     dispatchFakeEvent();
40   }
41 };