Loopback jQuery AJAX Request

Question

What is the best way to build a loopback URL for an AJAX call? Say I have a page at

http://www.mydomain.com/some/subdir/file.php

that I want to load with an AJAX call. In Firefox, using jQuery this works fine:

$.post('/some/subdir/file.php', ...);

Safari/WebKit tries to interpret this as a location on the local filesystem (so it ends up translating to 'file://some/subdir/file.php'). Not only does this not point to anything useful, it also results in a security error.

Is there a way to accomplish this without hard-coding the domain into the URL? I'd like to make this as domain-independent as possible.

Update

I ended up parsing out the base url from location.href and throwing it into an accessible jQuery function like this:

/**
 * Retrieves the current root URL.
 *
 * @return string the root URL
 */
$.fn.rootUrl = function() {
 var url = location.href;
 return url.substring(0, url.indexOf('/', 7));
};

Answer 1

Wow, that's pretty poor of Safari/WebKit, IMO.

You could observe document.href, count the slashes, and add that many "../" to the beginning of your URL.

Answer 2

You could have the server insert its own URL as a javascript variable when it serves up the page, then use that variable as part of your Ajax calls. It would then be both secure and automatic.

Answer 3

Alternatively, you can assemble your URL as follows:

'http://'+document.domain