function is_sortable($column = null) {
        if (empty($column)) {
            return $this->is_sortable;
        }
        if (!$this->is_sortable) {
            return false;
        }
        return !in_array($column, $this->column_nosort);
    }
function is_sortable($column = null) {
        if (empty($column)) {
            return $this->is_sortable;
        }
        if (!$this->is_sortable) {
            return false;
        }
        return !in_array($column, $this->column_nosort);
    }
function is_sortable ( $ column = null ) { if ( empty ( $ column ) ) { return $ this -> is_sortable ; } if ( ! $ this -> is_sortable ) { return false ; } return ! in_array ( $ column , $ this -> column_nosort ) ; }
Is the column sortable?
@param string column name, null means table
@return bool
Is the column sortable?