Image rotation

Hey guys

I have been using this one, but sometimes when I load a page the banner image shows nothing but blank. But then when I load another page, then it shows the image.

<?php

/**********************
* Image Rotater
***********************
* Written by Joel Larson (Coded Caffeine)
* http://thejoellarson.com/
*
* Allows a person to add images with descriptions
*   and pick an image randomly from a list.
**********************/
# Defined variables from paranoia.
$images = array();
$output = '';
/*********************/

# Copy/paste as many as you need.
# There are two shown for an example! (Make sure they are unique!)
$images[] = array(
    'path' => 'URL',
    'alternate' => 'ALTERNATE TEXT',
    'title' => 'DESCRIPTION'
);

$images[] = array(
    'path' => 'URL',
    'alternate' => 'ALTERNATE TEXT',
    'title' => 'DESCRIPTION'
);

# Set the int for total images in the first array level.
$total_images = count($images);

# Using mt_rand because it's faster than rand().
$id = mt_rand(0, $total_images);

/**
* Set the output that's being generated.
*/

# If a path is defined..
if( ! empty($images[$id]['path']))
{
    # Create the image with path.
   $output =  '<img src="'.$images[$id]['path'].'" ';
   
    # If the alt text is defined, add it.
   if( ! empty($images[$id]['alternate']))
        $output .= 'alt="'.$images[$id]['alternate'].'" ';
   
    # If the title text is defined, add it.
   if( ! empty($images[$id]['title']))
        $output .= 'title="" ';

    $output .= '/>';
}

# Echo the result.
echo $output;

?>

HTML:

Am I missing something here?

 

Give the example of how you're using the source and I'll be happy to help.

 

Ok thanks CodedCaffeine,

Here it is:

<div id="banner">
    	<strong>Title</strong>
        <?php

/**********************
* Image Rotater
***********************
* Written by Joel Larson (Coded Caffeine)
* http://thejoellarson.com/
*
* Allows a person to add images with descriptions
*   and pick an image randomly from a list.
**********************/
# Defined variables from paranoia.
$images = array();
$output = '';
/*********************/

# Copy/paste as many as you need.
# There are two shown for an example! (Make sure they are unique!)
$images[] = array(
    'path' => 'http://www.test.com/wp-content/themes/mark/images/bg-home.jpg',
    'alternate' => 'ALTERNATE TEXT',
    'title' => 'Contact'
);

$images[] = array(
    'path' => 'http://www.test.com/wp-content/themes/mark/images/bg-bio.jpg',
    'alternate' => 'ALTERNATE TEXT',
    'title' => 'Mark Lowdnes biography'
);

$images[] = array(
    'path' => 'http://www.test.com/wp-content/themes/mark/images/bg-gallery.jpg',
    'alternate' => 'ALTERNATE TEXT',
    'title' => 'Video'
);
$images[] = array(
    'path' => 'http://www.test.com/wp-content/themes/mark/images/bg-blog.jpg',
    'alternate' => 'ALTERNATE TEXT',
    'title' => 'Home'
);

$images[] = array(
    'path' => 'http://www.test.com/wp-content/themes/mark/images/bg-video.jpg',
    'alternate' => 'ALTERNATE TEXT',
    'title' => 'Biography'
);

$images[] = array(
    'path' => 'http://www.test.com/wp-content/themes/mark/images/bg-contact.jpg',
    'alternate' => 'ALTERNATE TEXT',
    'title' => 'Gallery'
);

# Set the int for total images in the first array level.
$total_images = count($images);

# Using mt_rand because it's faster than rand().
$id = mt_rand(0, $total_images);

/**
* Set the output that's being generated.
*/

# If a path is defined..
if( ! empty($images[$id]['path']))
{
    # Create the image with path.
    $output =  '<img src="'.$images[$id]['path'].'" ';
   
    # If the alt text is defined, add it.
    if( ! empty($images[$id]['alternate']))
        $output .= 'alt="'.$images[$id]['alternate'].'" ';
   
    # If the title text is defined, add it.
    if( ! empty($images[$id]['title']))
        $output .= 'title="" ';

    $output .= '/>';
}

# Echo the result.
echo $output;
?>
  </div>

Code (markup):

I am using this 'Image Rotation' inside my Wordpress site on the header.php file, hope that doesn't have any effect on it??

 

Hah, had a bug in the script.

Change this line:

# Using mt_rand because it's faster than rand().
$id = mt_rand(0, $total_images);

PHP:

To this:

# Using mt_rand because it's faster than rand().
$id = mt_rand(0, --$total_images);

PHP:

 

YES!! It works perfectly. Every time I press the Reload or Refresh button the image changes without stumbling across a blank page. Thanks heaps CodedCaffeine.

CHEERS

 

My counter was a little bit off.. hah.

When you use count() with an array, it counts the members of the array (Which say returned (int)6 ). The array itself can only be accessed with using $image[$id] with the $id being 0-5 (which is also (int)6 ). What my code did was search from 0-6, when there was only 5 images, so by reducing the value of the total images by 1, it will access it properly.

 

I see now why there was an extra blank page. This is very handy, I'm beginning like PHP more and more

 

Yeah, it's an index issue. An array populated in this way has an 0-based index. So here's what heppens in the code I quoted:

The array is populated with two images.

The number of images (2) is retrieved.

A random ID between 0 and 2 is generated (here is your problem).

The random ID is used to access the array, which has elements of 0 and 1. So if your random number between 0 and 2 was 2, you don't see any image.

It doesn't matter if you have 2 images or 200, you can always generate an ID that's one higher than the actual number of IDs used in the array.

The easy fix is to update your random number generation like this:

$id = mt_rand(0, $total_images - 1);

PHP: