public function getMessages()
    {
        $messages = parent::getMessages();

        if ($this->model !== null) {
            foreach ($this->model as $row) {
                foreach ($this->columns as $column) {
                    $messages = array_merge(
                        $messages,
                        $column->getMessages($row)
                    );
                }

                foreach ($this->spanning_columns as $column) {
                    $messages = array_merge(
                        $messages,
                        $column->getMessages($row)
                    );
                }
            }

            foreach ($this->extra_rows as $row) {
                if ($row instanceof SwatTableViewWidgetRow) {
                    $messages = array_merge($messages, $row->getMessages());
                }
            }
        }

        return $messages;
    }