Support/Comments for NG!Redirect

/*####
#
#   Name: NG!Redirect
#   Version: 0.0.2
#   Author: Stefan Bruggmann - http://www.ng-projects.ch
    @modified: Olivier B. Deland
#   Date: Apr 10, 2008 13:12 CET
#
# Latest Version: http://modxcms.com/...
# In use on Site: http://www.ng-studio.ch
#
####
#
#
# Usage:
# Enter your old Site-Names and the new static ones or dynamic id's to the following array like..
#
# Example:
# $sites = array(
#   'The-Old-URL-Without-Extension' => 6,
#   'Another-Old-URL' => 'A-New-Hard-Link'
# );
#
####
*/

$sites = array(
    'shop/products/thing.html' => 'shop/products/newthing.html',
    'index.html' => 1
);

$e = &$modx->Event;
switch ($e->name) {
    case "OnPageNotFound":
        $requestedURL = $modx->virtualDir.'/'.$modx->documentIdentifier;
        if (isset($sites[$requestedURL])) {
            if( is_numeric($sites[$requestedURL]) ){
                $url = $modx->makeUrl($sites[$requestedURL],'','','full');
            }
            else{
                $url = $sites[$requestedURL];
            }
            $this->sendRedirect($url, 0, 'REDIRECT_HEADER', 'HTTP/1.1 301 Moved Permanently');
            exit;
        }
        break;
        
    default :
        return; // stop here
}