Facebook Development and $_SERVER['HTTP_REFERER']

The solution to this problem is relatively simple, assuming your web site has at least ONE file that you include on every single page of the site.  Either a header.php, a config.php, etc...  If you don't have this, you might be required to copy and paste the code into each page of your web site.

if (array_key_exists('current_url', $_SESSION))

     $_SESSION['HTTP_REFERER'] = $_SESSION['current_url'];

$_SESSION['current_url'] = $_SERVER['REQUEST_URI'];

By adding the following code to a global template, $_SESSION['HTTP_REFERER'] now contains what the previous page the user was one.

Please note, this might not work right out of the box for you.  A couple of problems can occur.  My applications are built with a framework and $_SERVER['REQUEST_URI'] is built perfectly for me because it doesn't use query string variables.

So, if your application requires the query string as well.  Simply update the code and append the following (this should go after setting the current_url):

if (!empty($_SERVER['QUERY_STRING']))

     $_SESSION['current_url'] .= "?" . $_SERVER['QUERY_STRING'];

Hopefully this comes in handy during your next Facebook application.

Published on Feb 15, 2009

Tags: Facebook | php | PHP