rss_featured_image.php

<?php
/*
Plugin Name: RSS Featured Image
Description: Add featured image to rss feed.
Version: 1.0
*/

/*
 * Code minimized from 
 * WP RSS Images (http://web-argument.com/wp-rss-images-wordpress-plugin/)
 */


function wp_rss_img_do_feed($for_comments)
{
	if(!$for_comments){
		add_action('rss2_ns', 'wp_rss_img_adding_yahoo_media_tag');
		add_action('rss_item', 'wp_rss_img_include');
		add_action('rss2_item', 'wp_rss_img_include');
	}
}

function wp_rss_img_include ()
{
	
	$image_url = wp_rss_img_url();
	
	if (!empty($image_url)){	  
		$uploads = wp_upload_dir();
		$url = parse_url($image_url);
		$path = $uploads['basedir'] . preg_replace('/.*uploads(.*)/', '${1}', $url['path']);
		if (file_exists($path))
		{
			$url = $path;
		} else {
			$ary_header = get_headers($image_url, 1);
			$url = $image_url;
		}

		list($width, $height, $type, $attr) = getimagesize($url);
		echo '<media:content url="'.$image_url.'" width="'.$width.'" height="'.$height.'" medium="image" type="'.image_type_to_mime_type($type).'" />';
	}
}

function wp_rss_img_url($size = 'full') {
	global $post;
	if(function_exists('has_post_thumbnail') && has_post_thumbnail($post->ID)){
		$thumbnail_id = get_post_thumbnail_id($post->ID);
		if(!empty($thumbnail_id)){
			$img = wp_get_attachment_image_src($thumbnail_id, $size);
		}
	} else {
		$attachments = get_children( array(
				'post_parent' => $post->ID,
				'post_type' => 'attachment',
				'post_mime_type' => 'image',
				'orderby' => 'menu_order',
				'order' => 'ASC',
				'numberposts' => 1) );
		if($attachments == true) {
			foreach($attachments as $id => $attachment){
				$img = wp_get_attachment_image_src($id, $size);
			}
		}
	}
	if (isset($img)) return $img[0];
}

function wp_rss_img_adding_yahoo_media_tag(){
	echo 'xmlns:media="http://search.yahoo.com/mrss/"';
}

add_action("do_feed_rss", "wp_rss_img_do_feed", 5, 1);
add_action("do_feed_rss2", "wp_rss_img_do_feed", 5, 1); 

?>