silverstripe-blog/code/widgets/SubscribeRSSWidget.php

<?php
if(class_exists('Widget')) {
	/**
	 * A simple widget that just shows a link
	 * to this website's blog RSS, with an RSS
	 * icon.
	 * 
	 * @package blog
	 */
	class SubscribeRSSWidget extends Widget {
		
	private static $title = 'Subscribe via RSS';
		
	private static $cmsTitle = 'Subscribe via RSS widget';
		
	private static $description = 'Shows a link allowing a user to subscribe to this blog via RSS.';

		/**
		 * Return an absolute URL based on the BlogHolder
		 * that this widget is located on.
		 * 
		 * @return string
		 */
		function getRSSLink() {
			Requirements::themedCSS('subscribersswidget');
			$container = BlogTree::current();
			if ($container) return $container->Link('rss');
		}
	}

}