protected function _beforeSave(Kwf_Model_Row_Interface $row, $submitRow) { parent::_beforeSave($row, $submitRow); foreach ($this->_colNames as $colName) { if (!$row->{$colName}) { $row->{$colName} = null; } else { if ($row->{$colName} == ' ') { $row->{$colName} = ''; } } } }