Okay, this has been bugging me. I've been making some changes to a client's site, and I'm trying out a little time-saver... since it would take me years to manually change it.

Firstly, here's the HTML for an image used hundreds of times throughout the site:

<img src="images/no_image.gif" />

I've changed the .htaccess file to redirect the image to a PHP file called 'randImg.php' like so:

RewriteEngine on
RewriteRule ^images/no_image.gif$ randImg.php

My 'randImg.php' uses GD to output one of four new random images:

<?PHP

header("Content-type: image/png");

$temp = rand(1,4);
$path = "images/myauction/fish".$temp.".png";
$i = imagecreatefrompng($path);
imagepng($i);
imagedestroy($i); 

?>

Firstly, this pretty much works (shocker I know... at least it was for me). Every time I refresh the page, I get 1 of the 4 images randomly.

HOWEVER... If there is more than one of these 'no_image.gif's on each page, it displays the same image for each of them.

I thought it might have something to do with the browser assuming each image will be the same, but I don't know how to get round this.

Not sure where to go... any help greatly appreciated.

It's a user based caching problem. The user download a file, it's stored then next time the same URL is referred to the image will be the one stored on the users PC.

You could add some headers such as 'no cache', but on a single page it's a bit of a pain

Try:

PHP Code:

<?PHP
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Expires: Sat, 26 Jul 1997 05:00:00 GMT"); // Date in the past
header( 'Pragma: no-cache' );    
header("Content-type: image/png");

$temp = rand(1,4);
$path = "images/myauction/fish".$temp.".png";
$i = imagecreatefrompng($path);
imagepng($i);
imagedestroy($i);

Thanks rogem002,

I'm gonna try something else. After a little more research you're obviously right.

The browser would see each image as different if they all had different image sources. So if the images looked like this:

<img src='randImg.php?id=1' />

...and the id variable changed for each... then it would assume each image was different. The id variable itself isn't used, it would just be there to fool the browser

I still uphold that I'm not going to trawl through the code manually, so I'll be storing the pages in the buffer (ob_start() in prepend file) and at the end replacing any 'no_image.gif' files with the php script above. Simple... I hope.

Any quicker and easier solution readily accepted... I'll let you know how i get on.

Thanks

http://scriptplayground.com/tutorial...-Image-Loader/

Thanks for the link Aaron!

Unfortunately it's not generating the random image that I'm having trouble with (my thread title was sort of misleading I suppose). What I'm having problems with is is generating the random image in place of 'no_image.gif'!

Thanks again

Simple solution, add a date code to the name of the file!

Do you think redirecting to the image instead of including it would work? Like:

PHP Code:

<?PHP


$temp = rand(1,4);
$path = "images/myauction/fish".$temp.".png";

header('location: http://www.site.com/'.$path)

?>