Random header image using CSS

HI everyone,

I'm fairly new to CSS and playing around with it just now.

I've trying to set up CSS so that it displays a random header on each page load, i've done it before using java but trying to stay clear of that now.

I've no idea where to start, can anyone give any pointers?

Thanks
Peter

 

Yes you can point your css php page which returns a random image each time it loads. Or just include a file like this:

<?php

/*

	AUTOMATIC IMAGE ROTATOR
	Version 2.2 - December 4, 2003
	Copyright (c) 2002-2003 Dan P. Benjamin, Automatic, Ltd.
	All Rights Reserved.

	http://www.hiveware.com/imagerotator.php
	
	http://www.automaticlabs.com/
	
	
	DISCLAIMER
	Automatic, Ltd. makes no representations or warranties about
	the suitability of the software, either express or
	implied, including but not limited to the implied
	warranties of merchantability, fitness for a particular
	purpose, or non-infringement. Dan P. Benjamin and Automatic, Ltd.
	shall not be liable for any damages suffered by licensee
	as a result of using, modifying or distributing this
	software or its derivatives.
	
	
	ABOUT
	This PHP script will randomly select an image file from a
	folder of images on your webserver.  You can then link to it
	as you would any standard image file and you'll see a random
	image each time you reload.
	
	When you want to add or remove images from the rotation-pool,
	just add or remove them from the image rotation folder.


	VERSION CHANGES
	Version 1.0
		- Release version
	
	Version 1.5
		- Tweaked a few boring bugs
	
	Version 2.0
		- Complete rewrite from the ground-up
		- Made it clearer where to make modifications
		- Made it easier to specify/change the rotation-folder
		- Made it easier to specify/change supported image types
		- Wrote better instructions and info (you're them reading now)
		- Significant speed improvements
		- More error checking
		- Cleaner code (albeit more PHP-specific)
		- Better/faster random number generation and file-type parsing
		- Added a feature where the image to display can be specified
		- Added a cool feature where, if an error occurs (such as no
		  images being found in the specified folder) *and* you're
		  lucky enough to have the GD libraries compiled into PHP on
		  your webserver, we generate a replacement "error image" on
		  the fly.
		
    Version 2.1
        - Updated a potential security flaw when value-matching
          filenames

    Version 2.2
        - Updated a few more potential security issues
        - Optimized the code a bit.
        - Expanded the doc for adding new mime/image types.

        Thanks to faithful ALA reader Justin Greer for
        lots of good tips and solid code contribution!


	INSTRUCTIONS
	1. Modify the $folder setting in the configuration section below.
	2. Add image types if needed (most users can ignore that part).
	3. Upload this file (rotate.php) to your webserver.  I recommend
	   uploading it to the same folder as your images.
	4. Link to the file as you would any normal image file, like this:

			<img src="http://example.com/rotate.php">

	5. You can also specify the image to display like this:

			<img src="http://example.com/rotate.php?img=gorilla.jpg">
		
		This would specify that an image named "gorilla.jpg" located
		in the image-rotation folder should be displayed.
	
	That's it, you're done.

*/




/* ------------------------- CONFIGURATION -----------------------


	Set $folder to the full path to the location of your images.
	For example: $folder = '/user/me/example.com/images/';
	If the rotate.php file will be in the same folder as your
	images then you should leave it set to $folder = '.';

*/


	$folder = '.';


/*	

	Most users can safely ignore this part.  If you're a programmer,
	keep reading, if not, you're done.  Go get some coffee.

    If you'd like to enable additional image types other than
	gif, jpg, and png, add a duplicate line to the section below
	for the new image type.
	
	Add the new file-type, single-quoted, inside brackets.
	
	Add the mime-type to be sent to the browser, also single-quoted,
	after the equal sign.
	
	For example:
	
	PDF Files:

		$extList['pdf'] = 'application/pdf';
	
    CSS Files:

        $extList['css'] = 'text/css';

    You can even serve up random HTML files:

	    $extList['html'] = 'text/html';
	    $extList['htm'] = 'text/html';

    Just be sure your mime-type definition is correct!

*/

    $extList = array();
	$extList['gif'] = 'image/gif';
	$extList['jpg'] = 'image/jpeg';
	$extList['jpeg'] = 'image/jpeg';
	$extList['png'] = 'image/png';
	

// You don't need to edit anything after this point.


// --------------------- END CONFIGURATION -----------------------

$img = null;

if (substr($folder,-1) != '/') {
	$folder = $folder.'/';
}

if (isset($_GET['img'])) {
	$imageInfo = pathinfo($_GET['img']);
	if (
	    isset( $extList[ strtolower( $imageInfo['extension'] ) ] ) &&
        file_exists( $folder.$imageInfo['basename'] )
    ) {
		$img = $folder.$imageInfo['basename'];
	}
} else {
	$fileList = array();
	$handle = opendir($folder);
	while ( false !== ( $file = readdir($handle) ) ) {
		$file_info = pathinfo($file);
		if (
		    isset( $extList[ strtolower( $file_info['extension'] ) ] )
		) {
			$fileList[] = $file;
		}
	}
	closedir($handle);

	if (count($fileList) > 0) {
		$imageNumber = time() % count($fileList);
		$img = $folder.$fileList[$imageNumber];
	}
}

if ($img!=null) {
	$imageInfo = pathinfo($img);
	$contentType = 'Content-type: '.$extList[ $imageInfo['extension'] ];
	header ($contentType);
	readfile($img);
} else {
	if ( function_exists('imagecreate') ) {
		header ("Content-type: image/png");
		$im = @imagecreate (100, 100)
		    or die ("Cannot initialize new GD image stream");
		$background_color = imagecolorallocate ($im, 255, 255, 255);
		$text_color = imagecolorallocate ($im, 0,0,0);
		imagestring ($im, 2, 5, 5,  "IMAGE ERROR", $text_color);
		imagepng ($im);
		imagedestroy($im);
	}
}

?>

Code (markup):

Hope that helps

 

I think you still need some underlying script to 'randomize' your selections. You can't just do it with pure css.