/redirect/code/trunk/plugins/system/redirect.php

<?php
/**
 * @version		$Id: redirect.php 580 2011-02-25 05:11:47Z eddieajau $
 * @package		NewLifeInIT
 * @subpackage	plgSystemRedirect
 * @copyright	Copyright 2005 - 2010 New Life in IT Pty Ltd. All rights reserved.
 * @license		GNU General Public License <http://www.gnu.org/copyleft/gpl.html>
 * @link		http://www.theartofjoomla.com
 */

defined('JPATH_BASE') or die;

/**
 * Plugin class for Redirect.
 *
 * @package		NewLifeInIT
 * @subpackage	plgSystemRedirect
 * @since		1.0
 */
class plgSystemRedirect extends JPlugin
{
	/**
	 * Method to handle hard errors and catch 404 not found errors.
	 *
	 * @param	object	JException object.
	 * @return	void
	 * @since	1.0
	 */
	public static function handleError(&$error)
	{
		// Get the application object.
		$app = JFactory::getApplication();

		// Only apply special error handling if the error is a 404 and we aren't in the admin.
		if (!$app->isAdmin() and ($error->code == 404)) {
			// Get the current requested URI.
			$currentURI = JURI::getInstance()->toString(array('scheme', 'host', 'port', 'path', 'query', 'fragment'));

			// Attempt to ignore idiots.
			if ((strpos($currentURI, 'mosConfig_') !== false) || (strpos($currentURI, '=http://') !== false)) {
				JError::customErrorPage($error);
			}

			// Get the database connection object.
			$db = JFactory::getDBO();

			// Check to see if a redirect is set for the current URI.
			$db->setQuery(
				'SELECT `id`, `new_url`, `published`' .
				' FROM `#__redirect_links`' .
				' WHERE `old_url` = '.$db->quote($currentURI),
				0, 1
			);
			$link = $db->loadObject();

			// If the redirect exist and is published redirect the browser.
			if ($link && ($link->published == 1)) {
				$app->redirect($link->new_url, null, null, true);
			}
			// Render the Joomla! error page and add the URI to the database if necessary.
			else {
				// Add the current URI to the database if not present.
				if (empty($link)) {
					$now = JFactory::getDate();
					$referer = @$_SERVER['HTTP_REFERER'];
					$db->setQuery(
						'INSERT INTO `#__redirect_links` (`old_url`, `referer`, `published`, `created_date`, `hits`)' .
						' VALUES ('.$db->quote($currentURI).', '.$db->quote($referer).', 0, '.$db->quote($now->toMySQL()).', 1)'
					);
					$db->query();
				}
				// Increase the hit counter if it is present.
				else {
					$db->setQuery(
						'UPDATE `#__redirect_links`' .
						' SET `hits` = `hits` + 1' .
						' WHERE `id` = '.(int) $link->id
					);
					$db->query();
				}

				// Render the Joomla! error page.
				JError::customErrorPage($error);
			}
		}
		// We are either in the administrator application or have a non-404 error.
		else {
			// Render the Joomla! error page.
			JError::customErrorPage($error);
		}
	}
}

// Reset the hard error handling to use the plugin callback.
JError::setErrorHandling(E_ERROR, 'callback', array('plgSystemRedirect', 'handleError'));