public function callback_before_insert($callback = null, $override_all = 0) { if (!$override_all) { $this->callback_before_insert_ext[] = $callback; if ($this->callback_before_insert == null) { $this->callback_before_insert = array($this, 'extended_callback_before_insert'); } } else { parent::callback_before_insert($callback); } return $this; }