last-modified и if-modified-since для Joomla 1.5/2.5 - страница 9 - Поисковая оптимизация, продвижение сайтов на Joomla (SEO)

// last-modified/if-modified-since

$LastModified_unix = unix_time($this->item->modified);
$LastModified = gmdate("D, d M Y H:i:s \G\M\T", $LastModified_unix);
$IfModifiedSince = false;
if (isset($_ENV['HTTP_IF_MODIFIED_SINCE']))
	$IfModifiedSince = strtotime(substr($_ENV['HTTP_IF_MODIFIED_SINCE'], 5));
if (isset($_SERVER['HTTP_IF_MODIFIED_SINCE']))
	$IfModifiedSince = strtotime(substr($_SERVER['HTTP_IF_MODIFIED_SINCE'], 5));
if ($IfModifiedSince && $IfModifiedSince >= $LastModified_unix) {
	header($_SERVER['SERVER_PROTOCOL'] . ' 304 Not Modified');
	exit;
}

header('Last-Modified: '. $LastModified);

function unix_time($time_send){
	$year_lm=substr($time_send, 0, 4);
	$mount_lm=substr($time_send, 5, 2);
	$day_lm=substr($time_send, 8, 2);
	$time_lm=substr($time_send, 10, 9);
	$time_lm_unix_in = $year_lm.'-'.$mount_lm.'-'.$day_lm.' '.$time_lm;
	$select_lm = strtotime($time_lm_unix_in);
	return $select_lm;
}

 defined('_JEXEC') or die('Restricted access'); 

$last_modified =  strtotime($this->product->modified_on);
 
  JResponse::setHeader('Last-Modified',gmdate('D, d M Y H:i:s', $last_modified).' GMT');

   if(isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) &&      
        strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE'])>=$last_modified){

   	header($_SERVER['SERVER_PROTOCOL'].' 304 Not Modified');

   	die;

   	} 

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(JRequest::getVar('view')=='frontpage')
{
       $id_lm = '46';//ставим id cвоего материала на главной
}
elseif ( JRequest::getVar('page')=='shop.product_details' && JRequest::getVar('product_id')) { $id_lm = JRequest::getVar('product_id'); $virt_active=1;}
elseif(JRequest::getVar('id')){
   $id_lm = JRequest::getVar('id');
}
else{$num=mt_rand(2000,10000);
   $lastmodsite = gmdate("D, d M Y H:i:s",time()-$num).' GMT';
   
//header('Last-Modified: '.gmdate('D, d M Y H:i:s \G\M\T', time()-$num));
};
if($id_lm){
   //Запрос к функции класса запрос к БД
  if ($virt_active==1) { $result = JResponse::getDblm('mdate','#__vm_product','product_id',$id_lm);
$select_lm=$result;
 $day_lm_unix = date('D',$result);
 $day_lm=date('j',$result);
   $mount_lm_unix = date('M',$result);
$year_lm=date('Y',$result);
 $lastmodsite = $day_lm_unix.', '.$day_lm.' '.$mount_lm_unix.' '.$year_lm.' '.$time_lm.' GMT';
  }
   else {  
   $result = JResponse::getDblm('modified','#__content','id',$id_lm);
  
   //Разбиваем на значения
   $year_lm=substr($result, 0, 4);
   $mount_lm=substr($result, 5, 2);
   $day_lm=substr($result, 8, 2);
   $time_lm=substr($result, 10, 9);
   //Переводим в UNIX-формат и получаем текстовые значения дня и месяца
   $time_lm_unix_in = $year_lm.'-'.$mount_lm.'-'.$day_lm.' '.$time_lm;
   $day_lm_unix = date('D',strtotime($time_lm_unix_in));
   $mount_lm_unix = date('M',strtotime($time_lm_unix_in));
        //Сохраняем значение для поверки If-modified-since
   $select_lm = strtotime($time_lm_unix_in);
   //Формируем last-modified                                       
       $lastmodsite = $day_lm_unix.', '.$day_lm.' '.$mount_lm_unix.' '.$year_lm.' '.$time_lm.' GMT';
	    }
}
  /*       
if(isset($_ENV['HTTP_IF_MODIFIED_SINCE']) && $id_lm){    
         $IfModifiedSince = strtotime(substr($_ENV['HTTP_IF_MODIFIED_SINCE'], 5));  
    if($select_lm <= $IfModifiedSince){
      header($_SERVER['SERVER_PROTOCOL'] . ' 304 Not Modified');
   };
};  */

if(isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) && strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE'])>=$select_lm){

	header($_SERVER['SERVER_PROTOCOL'].' 304 Not Modified');    exit;   }
         
JResponse::setHeader( 'Expires', 'Mon, 1 Jan 2001 00:00:00 GMT', true );                     
JResponse::setHeader('Last-Modified',$lastmodsite,true);

JResponse::setHeader( 'Cache-Control', 'no-store, no-cache, must-revalidate, post-check=0, pre-check=0', false);
JResponse::setHeader( 'Pragma', 'no-cache' );
			
///////////////////			
		

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

if(isset($_SERVER['HTTP_IF_MODIFIED_SINCE']) && strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE'])>= $select_lm && $id_lm){

	header($_SERVER['SERVER_PROTOCOL'].' 304 Not Modified');    exit;   }