public function getSortBy()
    {
        $sortBy = isset($this->requestParams[self::PARAM_SORT_BY]) ?
            $this->requestParams[self::PARAM_SORT_BY] : self::DEFAULT_SORT_BY;
        return $sortBy;
    }
public function getSortBy()
    {
        $sortBy = isset($this->requestParams[self::PARAM_SORT_BY]) ?
            $this->requestParams[self::PARAM_SORT_BY] : self::DEFAULT_SORT_BY;
        return $sortBy;
    }
public function getSortBy ( ) { $ sortBy = isset ( $ this -> requestParams [ self :: PARAM_SORT_BY ] ) ? $ this -> requestParams [ self :: PARAM_SORT_BY ] : self :: DEFAULT_SORT_BY ; return $ sortBy ; }
Get sorting column name
@return string
Get sorting column name