How to add custom nodes to WordPress RSS feed

Recently I was working on a WordPress site and wanted to add a custom node to the WordPress RSS Feeds. In my previous post How to add featured image to WordPress RSS feed we saw how to add a featured image to the post content in RSS Feed. In this post we will see how we can add any node to the RSS Feed. To add a custom node in the RSS feed we just need to add some code to the theme’s functions.php file.

Important: Make sure to add the code to the functions.php file of your theme. Do not add it to the functions.php file in the wp-includes directory.

Here is an example code that you can add to the theme’s functions.php file to add the featured image as a node in the RSS Feed.

// Add the image node to RSS feed
function add_rss_node_image() {
	global $post;
	if(has_post_thumbnail($post->ID)):
		$thumbnail = get_attachment_link(get_post_thumbnail_id($post->ID));
		echo "<image>{$thumbnail}</image>";
	endif;
}

add_action('rss2_item', 'add_rss_node_image');

The above example add the featured image URL in the image node like this <image>featured_image_url</image>. You can add any custom nodes to the RSS Feed.

Here is an example to add the image and thumbnail nodes.

// Add the image and thumbnail node to RSS feed
function add_rss_node_image_thumbnail() {
	global $post;
	if (has_post_thumbnail($post->ID)):
		$image = wp_get_attachment_url(get_post_thumbnail_id($post->ID));
		$thumbnail = wp_get_attachment_thumb_url(get_post_thumbnail_id($post->ID));
		echo "<image>{$image}</image>
		<thumbnail>{$thumbnail}</thumbnail>";
	endif;
}
add_action('rss2_item', 'add_rss_node_image_thumbnail');