Comments on: How to Enable Client-Side Caching of Resized Images

By: suleiman

suleiman — Thu, 17 Apr 2008 22:55:58 +0000

is there a way to set expire headers for images that are not hosted on your server?

By: NL

NL — Sat, 12 Apr 2008 08:20:26 +0000

Apaches default behavour is to disable caching as much as possible. That is why default headers are applied.

You should be able to do:

– start of code –
// Expire in 1 day
$oDate = mktime(date(’H'), date(’i'), date(’s’), date(’m'), date(’d') + 1, date(’Y'));
header(’Expires: ‘ . date(’D, d M Y H:i:s’, $oDate) . ‘ GMT’);
– end of code –

But some servers override the expire-header anyway

By: NL

NL — Sat, 12 Apr 2008 08:19:12 +0000

Apaches default behavour is to disable caching as much as possible. That is why default headers are applied.

You should be able to do:

But some servers override the expire-header anyway

By: Pat

Pat — Mon, 10 Mar 2008 11:11:14 +0000

ok, I moved the cache control under the content-type:
header(’Content-type: image/jpeg’);
header(’Cache-Control: max-age=3600′);

and now the reponse header is saying 3600 instead of ‘ no-store, no-cache, must-revalidate, post-check=0, pre-check=0′

however I am still getting a passed expiry date.
as in the following reponse headers:

Date Mon, 10 Mar 2008 11:10:17 GMT
Server Apache/1.3.39 (Unix) mod_auth_passthrough/1.8 mod_log_bytes/1.2 mod_bwlimited/1.4 mod_jk/1.2.14 mod_ssl/2.8.30 OpenSSL/0.9.7a PHP-CGI/0.1b
Cache-Control max-age=3600
Expires Thu, 19 Nov 1981 08:52:00 GMT
Pragma no-cache
X-Powered-By PHP/5.2.1
Keep-Alive timeout=15, max=66
Connection Keep-Alive
Transfer-Encoding chunked
Content-Type image/jpeg

any idea why the expiry date would be in the past, the server time is correct
Pat

By: Pat

Pat — Mon, 10 Mar 2008 09:45:31 +0000

Hey, cheers for the tute.

I couldnt seem to get it to cache still, would calling the script through htaccess rewrite make any difference?

ie http://www.domain.com/image/4.jpg

Pat

By: Rich

Rich — Thu, 06 Mar 2008 16:21:11 +0000

Works like a charm!

Works in every browser (FF, IE, Safari, Opera..etc)