/plugins/system/admintools/response.php

<?php
/**
 * @version		$Id: response.php 77 2010-10-21 06:55:09Z nikosdion $
 * @package		Joomla.Framework
 * @subpackage	Environment
 * @copyright	Copyright (C) 2005 - 2008 Open Source Matters. All rights reserved.
 * @license		GNU/GPL, see LICENSE.php
 * Joomla! is free software. This version may have been modified pursuant
 * to the GNU General Public License, and as distributed it includes or
 * is derivative of works licensed under the GNU General Public License or
 * other free or open source software licenses.
 * See COPYRIGHT.php for copyright notices and details.
 *
 * Modified by Nicholas K. Dionysopoulos to handle GZip headers without conflicts
 */

/**
 * Create the response global object
 */
defined('JPATH_BASE') or die();

if(!class_exists('JResponse'))
{

	$GLOBALS['_JRESPONSE'] = new stdClass();
	$GLOBALS['_JRESPONSE']->cachable = false;
	$GLOBALS['_JRESPONSE']->headers  = array();
	$GLOBALS['_JRESPONSE']->body	 = array();

	 /**
	 * JResponse Class
	 *
	 * This class serves to provide the Joomla Framework with a common interface to access
	 * response variables.  This includes header and body.
	 *
	 * @static
	 * @package		Joomla.Framework
	 * @subpackage	Environment
	 * @since		1.5
	 */
	class JResponse
	{
		/**
		 * Set/get cachable state for the response
		 *
		 * If $allow is set, sets the cachable state of the response.  Always returns current state
		 *
		 * @static
		 * @param	boolean	$allow
		 * @return	boolean 	True of browser caching should be allowed
		 * @since	1.5
		 */
		function allowCache($allow = null)
		{
			if (!is_null($allow)) {
				$GLOBALS['_JRESPONSE']->cachable = (bool) $allow;
			}
			return $GLOBALS['_JRESPONSE']->cachable;
		}

		/**
		 * Set a header
		 *
		 * If $replace is true, replaces any headers already defined with that
		 * $name.
		 *
		 * @access public
		 * @param string 	$name
		 * @param string 	$value
		 * @param boolean 	$replace
		 */
		function setHeader($name, $value, $replace = false)
		{
			$name	= (string) $name;
			$value	= (string) $value;

			if ($replace)
			{
				foreach ($GLOBALS['_JRESPONSE']->headers as $key => $header) {
					if ($name == $header['name']) {
						unset($GLOBALS['_JRESPONSE']->headers[$key]);
					}
				}
			}

			$GLOBALS['_JRESPONSE']->headers[] = array(
				'name'	=> $name,
				'value'	=> $value
			);
		}

		/**
		 * Return array of headers;
		 *
		 * @access public
		 * @return array
		 */
		function getHeaders() {
			return  $GLOBALS['_JRESPONSE']->headers;
		}

		/**
		 * Clear headers
		 *
		 * @access public
		 */
		function clearHeaders() {
			$GLOBALS['_JRESPONSE']->headers = array();
		}

		/**
		 * Send all headers
		 *
		 * @access public
		 * @return void
		 */
		function sendHeaders()
		{
			if (!headers_sent())
			{
				$headers_sent = array();
				foreach ($GLOBALS['_JRESPONSE']->headers as $header)
				{
					$key = strtolower($header['name']);
					if(in_array($key, $headers_sent)) continue;
					$headers_sent[] = $key;
					if ('status' == $key)
					{
						// 'status' headers indicate an HTTP status, and need to be handled slightly differently
						header(ucfirst(strtolower($header['name'])) . ': ' . $header['value'], null, (int) $header['value']);
					} else {
						header($header['name'] . ': ' . $header['value']);
					}
				}
			}
		}

		/**
		 * Set body content
		 *
		 * If body content already defined, this will replace it.
		 *
		 * @access public
		 * @param string $content
		 */
		function setBody($content) {
			$GLOBALS['_JRESPONSE']->body = array((string) $content);
		}

		 /**
		 * Prepend content to the body content
		 *
		 * @access public
		 * @param string $content
		 */
		function prependBody($content) {
			array_unshift($GLOBALS['_JRESPONSE']->body, (string) $content);
		}

		/**
		 * Append content to the body content
		 *
		 * @access public
		 * @param string $content
		 */
		function appendBody($content) {
			array_push($GLOBALS['_JRESPONSE']->body, (string) $content);
		}

		/**
		 * Return the body content
		 *
		 * @access public
		 * @param boolean $toArray Whether or not to return the body content as an
		 * array of strings or as a single string; defaults to false
		 * @return string|array
		 */
		function getBody($toArray = false)
		{
			if ($toArray) {
				return $GLOBALS['_JRESPONSE']->body;
			}

			ob_start();
			foreach ($GLOBALS['_JRESPONSE']->body as $content) {
				echo $content;
			}
			return ob_get_clean();
		}

		/**
		 * Sends all headers prior to returning the string
		 *
		 * @access public
		 * @param boolean 	$compress	If true, compress the data
		 * @return string
		 */
		function toString($compress = false)
		{
			$data = JResponse::getBody();

			// Don't compress something if the server is going todo it anyway. Waste of time.
			if($compress && !ini_get('zlib.output_compression') && ini_get('output_handler')!='ob_gzhandler') {
				$data = JResponse::_compress($data);
			}

			if (JResponse::allowCache() === false)
			{
				JResponse::setHeader( 'Expires', 'Mon, 1 Jan 2001 00:00:00 GMT', true ); 				// Expires in the past
				JResponse::setHeader( 'Last-Modified', gmdate("D, d M Y H:i:s") . ' GMT', true ); 		// Always modified
				JResponse::setHeader( 'Cache-Control', 'no-store, no-cache, must-revalidate, post-check=0, pre-check=0', false );
				JResponse::setHeader( 'Pragma', 'no-cache' ); 											// HTTP 1.0
			}

			JResponse::sendHeaders();
			return $data;
		}

		/**
		* Compress the data
		*
		* Checks the accept encoding of the browser and compresses the data before
		* sending it to the client.
		*
		* @access	public
		* @param	string		data
		* @return	string		compressed data
		*/
		function _compress( $data )
		{
			$encoding = JResponse::_clientEncoding();

			if (!$encoding)
				return $data;

			if (!extension_loaded('zlib') || ini_get('zlib.output_compression')) {
				return $data;
			}

			if (headers_sent())
				return $data;

			if (connection_status() !== 0)
				return $data;


			$level = 4; //ideal level

			/*
			$size		= strlen($data);
			$crc		= crc32($data);

			$gzdata		= "\x1f\x8b\x08\x00\x00\x00\x00\x00";
			$gzdata		.= gzcompress($data, $level);

			$gzdata 	= substr($gzdata, 0, strlen($gzdata) - 4);
			$gzdata 	.= pack("V",$crc) . pack("V", $size);
			*/

			$gzdata = gzencode($data, $level);

			JResponse::setHeader('Content-Encoding', $encoding);
			JResponse::setHeader('X-Content-Encoded-By', 'Joomla! 1.5');

			return $gzdata;
		}

		 /**
		* check, whether client supports compressed data
		*
		* @access	private
		* @return	boolean
		*/
		function _clientEncoding()
		{
			if (!isset($_SERVER['HTTP_ACCEPT_ENCODING'])) {
				return false;
			}

			$encoding = false;

			if (false !== strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip')) {
				$encoding = 'gzip';
			}

			if (false !== strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'x-gzip')) {
				$encoding = 'x-gzip';
			}

			return $encoding;
		}
	}

}