Rotating images question

[Mr_Mako]

Hi...

I've got a quick question about rotating images. I'm working on a site where I have a banner across the top that I want to display a different image on a regular basis when the user browses to the site and / or while they are browsing the site.

I found a good peice of PHP code that works great... but it changes the image every time the browser either refreshes the same page or whenever a link is clicked and a new page comes up.

What I'd like to be able to do is have the code do one of two things...

1. Select the image randomly when the user first comes to the site and then stick with that same image throughout the entire session, or

2. Have the image rotate only so many refreshes or so many page links... like have it refresh after 10 link changes or 10 refreshes.

I'm not sure how to do this (or really even where to begin actually). The code I have now is as follows:

$dir=opendir("headers/");

$pattern="\.(gif|jpg|jpeg|png|bmp|swf)$";
if(!$dir) {
	die("Failed to read directory");
}

$s=readdir($dir);
$count="0";
$image;
while($s) {
	if(ereg($pattern, $s)) {
		$image[$count]=$s;
		$count++;
	}
	$s=readdir($dir);
}
closedir($dir);

// Display Image //
$limit=count($image);
$limit--;
$randNum=rand(0,$limit);

$directory = "headers/";

... and then I simply put the variables into the background image field of the table I'm using to display it in...

<table border="0" cellpadding="0" cellspacing="0" style="border-collapse: collapse" bordercolor="#111111" width="100%">
    <tr>
      <td width="100%" height="100" align="right" valign="middle" background="<?php echo "$directory$image[$randNum]"; ?>">
      <div align="center">

Any help would be greatly appreciated. The main reason I'd like to do this is to save on bandwidth... the background images are 1600 pixels wide by 300 high because I needed the image to stretch across the length of the page regardless of the user's browser window size.

[Weedpacket]

Well, assuming you're using session variables... consider: two session variables. One that stores the ID of the currently-showing banner, and one that counts page views (the former is initially chosen randomly, the latter is initially set to zero). Each page view, bump the view count up by one. When it gets to ten, change the banner ID, and set the count back to zero.

[Mr_Mako]

Ok... what you suggest makes perfect sense.

However... being honest enough with my own PHP coding skills, I don't have a very good idea of where to start with coding something like that... let alone actually accomplishing it.

I'm using sessions for the site users to log in... but that's about the limit of my session knowledge at this point.

So... with that in mind, perhaps it would be better for me to seek a solution more along the lines of #1 in my first post, and have a single random image that stays with the page for the entire session.

Is something like that any easier to do? I'm not trying to be lazy or anything... it's just that I don't have a lot of time to get this project up and running and need to get this resolved one way or another as soon as I can. I can work on the Session's suggestion at a later time and research how to accomplish that for the future.

[Weedpacket]

Originally posted by Mr_Mako
So... with that in mind, perhaps it would be better for me to seek a solution more along the lines of #1 in my first post, and have a single random image that stays with the page for the entire session.

Is something like that any easier to do?

Not significantly; all it would be would be leaving out the expressions mentioning $SESSION['banner_views'] below.

if(!isset($_SESSION['banner_id']) || $_SESSION['banner_views']==10)
{
	// New session, or ten views of current banner
	Randomly select new banner ID and put it in $_SESSION['banner_id']
	$_SESSION['banner_views']=0; // Reset counter
}
$_SESSION['banner_views']++; // Count this view.