The YUI connection manager use XMLHttpRequest to make remote call, hence calling cross domain URL is prohibited by the browser security model. This class is to solve this situation without the need to setup any server side proxy, while maintaining the same calling mechanism as the YUI connection manager.

Script source: http://rockstonesand.com/js/crossdomainmanager.js

Minified version: http://rockstonesand.com/js/crossdomainmanager_min.js

Usage: Same as YUI connection manager

Functions supported:

asyncRequest, isCallInProgress, abort

Example:
Client side:

<script src="http://rockstonesand.com/js/crossdomainmanager_min.js"></script>
<script>
// Same callback object definition as YUI connection manager
var callback = {
    success: function(obj) {
        var response = obj.responseText;
        // Do UI updates
    },
    failure: function(obj) {
    }
};
var txId = CrossDomainConnect.asyncRequest(
   "http://api.flickr.com/services/feeds/photos_public.gne?lang=en-us&format=json",
   callback,
   "jsoncallback");
</script>

Limitations:

• Only GET method is supported, as it uses script tag hack
• The target server side script must support an additional “callback” parameter for the connection manager to specify a callback function

Good framework for applying MVC design in Web Application.

http://yuiblog.com/blog/2007/09/13/bubbling-library-by-caridy/

Recently I was helping my colleague to fix a strange bug in his Javascript. The bug behave like this:

1. Open the web page in IE.
2. After everything are loaded (HTML, images, scripts, …), click on address bar and press enter
3. IE crashed

When I try to identify the bug, I’ve created a simple page that can reproduce the bug.

crash.html

<div id="panel"></div>
<a href="#" onclick="loadScript(); return false;">Load script</a>

<script>
    var n = 0;
    var callback = function() {
        n++;
        var panel = document.getElementById("panel");
        panel.innerHTML = "loadScript called " + n + " times.";
        var node = document.getElementById("testid");
        node.parentNode.removeChild(node);
    }

    var loadScript = function() {
        var node = document.createElement("script");
        node.src="crash.js";
        node.id = "testid";

        document.getElementsByTagName("head")[0].appendChild(node);
    }

    window.onload = loadScript;
</script>

crash.js

callback();

What the page does is to create a script node dynamically and insert into the document to load an external .js file. When the external “crash.js” is loaded, it calls a function to update the page content and remove the script node. IE will be crashed by either click on the address and hit enter button or just click on the link “Load script”.

The actual reason why IE crashes on this situation is unknown, but one thing can be sure is it only crashes if the same URL is being requested. If you try to append a dummy random query to the script src URL, IE is working fine.

I’ve also discovered another way, which I think is better in solving this problem. Simply use a setTimeout() function to wrap around the removeChild statement with timeout = 0.

setTimeout(function() {
    var node = document.getElementById("testid");
    node.parentNode.removeChild(node);
}, 0);

The problem will be gone by doing this.