mathie's bits

Normally, JavaScript document.write is used by ad servers to write the ad code directly into the page (AdSense, AdSpeed, OpenX, etc.) To reload ads automatically without a page reload, we use AJAX with JSONP (JSON with padding). Partial content reloading uses DOM to update the content. jQuery 1.2.x has this built-in, or you can write your own library.

We recently implemented jQuery into our ad server, majorly for future feature expansions and hopefully convert some of the existing JS enhancements using jQuery for a simpler codebase. Google AJAX API is nice but does not support SSL, which is quite inconvenient.

Consider the following scenario: file.html contains inline JS code to load remote.js and call a function in remote.js

<br /> <script text="text/javascript"></p> <p>alert('Before loading remote.js'); document.write('<sc'+'ript type="text/javascript" src="remote.js"><\/script>');</p> <p>alert('After loading remote.js'); document.write('<sc'+'ript type="text/javascript">remoteFunction();<\/script>');</p> <p></script><br />

And in remote.js
</p> <p>function remoteFunction() {<br /> alert(‘In remote function’);<br /> }</p> <p>

You would expect the output in this order and Firefox actually honors this order correctly:

1. Before loading remote.js
2. After loading remote.js
3. In remote function

IE on the other hand will give you an error (“Object Expected”) and will call the function prematurely. Meaning that it executes before loading remote.js. This is an unexpected behavior. Fortunately, you can add the attribute defer=”defer”. This will specifically prevent IE from executing and actually produce proper result. Hmm, it’s IE! It has its own style!

If you need to delay execution (like sleep function), use setTimeout. If you need to repeatedly do something (like refresh stats), use setInterval.

• window.setTimeout(“show();”,2000); // wait 2 seconds then run show()
• window.setInterval(“show();”,3000); // run show() every 3 seconds

The following Javascript code works in Firefox & Internet Explorer but not in Opera. Different browsers interpret Javascript code differently.

$pTxt = $pTxt.replace(/(.|\n)+<\/tag>/g,'');

This code works in all three.
$pTxt = $pTxt.replace(/[\s\S]+<\/tag>/g,'');