Jon Bergman on "Get current attached media"

get_attached_media works great to get attachments that have been uploaded or 'attached' to a given post or page. The problem is when you remove one of these attachments say an image from your gallery, get_attached_media still returns that image in the array because it was originally uploaded to the post/page. The only way to remove it would be to delete it permanently from your media. Vise versa, get_attached_media will return null if you create a new gallery on a page with images already existing in your media.

I am not looking for a plugin but rather a programmatic solutions to get attachments. I am using get_attached_media because it returns the original url rather than the thumbnail.

current code:

<?php if ( have_posts() ) : ?>
   <?php while ( have_posts() ) : the_post(); ?>
      <?php $attachments = get_attached_media( 'image', $post->ID ); ?>
         <?php if ( $attachments ) : ?>
	    <ul>
	    <?php foreach ( $attachments as $attachment ) : ?>
	       <li><img src="<?php echo  wp_get_attachment_url($attachment->ID ); ?>"/></li>
	    <?php endforeach; ?>
            </ul>
	<?php endif; ?>
     <?php endwhile; ?>
 <?php endif; ?>

Thanks!