+
+ /**
+ * Extracts the filter name from the given callback
+ *
+ * @param callback $function
+ * @return string
+ */
+ function _get_filter_name($function)
+ {
+ if (is_array($function)) {
+ $_class_name = (is_object($function[0]) ?
+ get_class($function[0]) : $function[0]);
+ return $_class_name . '_' . $function[1];
+ }
+ else {
+ return $function;
+ }
+ }
+