silverstripe-framework/admin/code/CMSPreviewable.php

<?php
/**
 * Interface to provide enough information about a record to make it previewable
 * through the CMS. It uses the record database ID, its "frontend" and "backend" links
 * to link up the edit form with its preview. 
 * 
 * Also used by {@link SilverStripeNavigator} to generate links - 
 * both within the CMS preview, and as a frontend utility 
 * for logged-in CMS authors in custom themes (with the $SilverStripeNavigator template marker).
 */
interface CMSPreviewable {
	
	/**
	 * @return String Absolute URL to the end-user view for this record.
	 * Example: http://mysite.com/my-record
	 */
	function Link();
	
	/**
	 * @return String Absolute URL to the CMS-author view. Should point to a controller subclassing {@link LeftAndMain}.
	 * Example: http://mysite.com/admin/edit/6
	 */
	function CMSEditLink();

}