htaccess Elite

Code: Select all

header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
header("Cache-Control: no-store, no-cache, must-revalidate");
header("Cache-Control: post-check=0, pre-check=0", false);
header("Pragma: no-cache");

Code: Select all

@header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
@header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
@header("Cache-Control: no-store, no-cache, must-revalidate");
@header("Cache-Control: post-check=0, pre-check=0", false);
@header("Pragma: no-cache");

Code: Select all

<?php
function get_http_mdate()
{
   return gmdate("D, d M Y H:i:s",filemtime($SCRIPT_FILENAME))." GMT";
}

function check_modified_header()
{
   // This function is based on code from http://ontosys.com/php/cache.html

   $headers=apache_request_headers();
   $if_modified_since=preg_replace('/;.*$/', '', $headers['If-Modified-Since']);
   if(!$if_modified_since)
       return;

   $gmtime=get_http_mdate();

   if ($if_modified_since == $gmtime) {
       header("HTTP/1.1 304 Not Modified");
       exit;
   }
}

check_modified_header();
header("Last-Modified: ".get_http_mdate());
?>

Code: Select all

<?php

  $file = getFileFromDB();

  // generate unique ID
  $hash = md5($file['contents']);
 
  $headers = getallheaders();
 
  // if Browser sent ID, we check if they match
  if (ereg($hash, $headers['If-None-Match']))
  {
   header('HTTP/1.1 304 Not Modified');
  }
  else
  {
   header("ETag: \"{$hash}\"");
   header("Accept-Ranges: bytes");
   header("Content-Length: ".strlen($file['content']));
   header("Content-Type: {$mime}");
   header("Content-Disposition: inline; filename=\"{$file['filename']}\";");

   echo $file['content'];
  }
  exit();
?>

If you are trying to modify headers to work with dynamic binaries such as videos or images, the new IE 7 appears to require the ETag header. You will need to make sure that you follow the specifications for how ETag works in order for your cache control to work properly. Mozilla supports the ETag header as well, but does NOT require it for caching. If you need to cache a dynamic image, video, or other binary file, and are having trouble in IE7, be sure to set your ETag and then check for the If-Not-Modified header on subsequent requests so that you can properly return the 304 Not Modified page. If you do not, then it will NEVER cache the file (as of IE version 7.0.5730.11