PHP Forum

**WMASTER** · 08-17-2008, 09:54 AM

Hello >>

This is my first visit and post in webmaster-talk. it's an honor and a privilege to be with you all.

As mentioned in thread subject

My site contain dynamic pages, it is a script using php&html with mysql database. Daily when i do update the pages through script's back-end, homepage will still showing the previous update until refreshing the page. and my visitors face the same problem.

I used 4 computers and 3 defferent ISP and that did not fix the issue, so it is not browser cache and not ISP cache, and there is no options in script's back-end to turn cache on or off. thats all make me sure it is server-side caching.

I'm looking for a way to prevent this because I'm constantly updating the site and it is impossible to ask my visitor "Please press refresh on each visit"

Apparently, there are "no-cache" code that can be put into meta
tags. I try this also .. but didn't work

I'd be grateful for any light that can be thrown on this server side
caching problem.

**bas** · 08-17-2008, 12:59 PM

Server side caching? never heard of that, you say:

Quote:

it is impossible to ask my visitor "Please press refresh on each visit"

but if refreshing helps, it should just be a browser (thus client-side) cache....

There is no water proof solution to prevent caching on every browser and every situation, but with Expires, Last-Modified and cache-control headers it should be possible to prevent in many cases.

**Truly** · 08-17-2008, 10:59 PM

Im no expert with caching but if you wait a bit Im sure you will get some good help with this issue. Until you do though, you can always force refresh the page.

This can be done through javascript or meta refresh. Im sure there is a better solution that one of the real experts on this site will give you but until you get that going you can use the forced refresh as a quick fix.

**WMASTER** · 08-18-2008, 11:20 AM

bas

I read about server-side cache in many pages on internet but still cannot find the solution.

Truly

I added this code in the header

<META HTTP-EQUIV="PRAGMA" CONTENT="NO-CACHE">
<META HTTP-EQUIV="CACHE-CONTROL" CONTENT="NO-CACHE">
<META HTTP-EQUIV="EXPIRES" CONTENT="Mon, 22 Jul 2002 11:12:01 GMT">

and many other similar lines BUT all didn't fix it

Any suggestions?

**bas** · 08-18-2008, 12:41 PM

What I actually meant where http-headers, for example with PHP: http://be.php.net/header

A post from that website:

Quote:

This is the Headers to force a browser to use fresh content (no caching) in HTTP/1.0 and HTTP/1.1:

PHP Code:


			
<?PHP 

header( 'Expires: Sat, 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' ); 

?>

**WMASTER** · 08-20-2008, 12:17 PM

Thanks bas, I will use this code but am afraid that I dont know where to add it becouse i have 2 header ...

/header.php
/language/english/html/skin/header.html

Site title and description and meta included in the first one "header.php"

This is the HEAD part:

PHP Code:


			
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title><?php if($site_title!=""){echo strip_tags(preg_replace('/\015\012|\015|\012|"/s',' ',$site_title));}else{echo SITE_TITLE;}?></title>
<?php if($site_title!=""){echo preg_replace(array('/<meta name="keywords" content="(.*)">/Usi','/<meta name="description" content="(.*)">/Usi'),array('<meta name="keywords" content="'.strip_tags(preg_replace('/\015\012|\015|\012|"/s',' ',$site_title)).'">','<meta name="description" content="'.strip_tags(preg_replace('/\015\012|\015|\012|"/s',' ',$site_title)).'">'),META);}else{echo META;}?>
<meta http-equiv="Content-Type" content="text/html; charset=<?php echo $CHARSET_OPTION;?>">
<?php 
if (!isset($css_file_dir)) {
$css_file_dir=HTTP_SERVER;
}
?>
<link rel="stylesheet" href="<?php echo $css_file_dir;?>css.php" type="text/css">
<?php
if (isset($extra_cssfile) && !empty($extra_cssfile)) {
echo "<link rel=\"stylesheet\" href=\"".$extra_cssfile."\" type=\"text/css\">";
}
if (!empty($jsfile)) {
echo "\n<script language=\"JavaScript1.1\" type=\"text/javascript\">";
echo "\n<!--\n";
include(DIR_LANGUAGES.$language."/javascript_messages.php");
include(DIR_JS.$jsfile);
echo "\n//-->\n</script>\n";
}
?>
</head>
<body dir="<?php echo $TEXTDIR_FORMAT;?>"<?php if(isset($body_onload)){echo " onLoad=\"".$body_onload."\"";}?>>
<!-- header //-->
<?php
if(!isset($bx_show_header) || $bx_show_header!="no") {
if($aff_menu==true){
@include(DIR_SKIN.'header_affiliates.html');
}
elseif ($_SESSION['userid']) {
@include(DIR_SKIN.'header_jobseeker.html');
}
elseif($_SESSION['employerid'] || ((SIDE_ALIGN=="separated_left" || SIDE_ALIGN=="separated_right" || SIDE_ALIGN=="separated_top") && $empl_menu==true)){
@include(DIR_SKIN.'header_employer.html');
}
else {
@include(DIR_SKIN.'header.html');
}
} 
?>
<!-- header_eof //-->

**bas** · 12:37 PM

It need to be before you print any content.

PHP Code:


			
<?php  

header( 'Expires: Sat, 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' );  

?>

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">

<html>

...

**WMASTER** · 08-21-2008, 04:35 PM

GREAT
It works very well now

Thank you so much for your help