add method isDescendant()

SeedDMS_Core/Core/inc.ClassDocument.php

@@ -519,6 +519,24 @@ class SeedDMS_Core_Document extends SeedDMS_Core_Object { /* {{{ */
 		return true;
 	} /* }}} */
 
+	/**
+	 * Check, if this document is below of a given folder
+	 *
+	 * @param object $folder parent folder
+	 * @return boolean true if folder is a subfolder
+	 */
+	function isDescendant($folder) { /* {{{ */
+		/* First check if the parent folder is folder looking for */
+		if ($this->getFolder()->getID() == $folder->getID())
+			return true;
+		/* Second, check for the parent folder of this document to be
+		 * below the given folder
+		 */
+		if($this->getFolder()->isDescendant($folder))
+			return true;
+		return false;
+	} /* }}} */
+
 	/**
 	 * Return the parent folder of the document
 	 *