Problems with Ignited Datatables

[eluser]cebalzer[/eluser]
I'm trying adapter my needs, but now is not working the sorting, can someone help me change the script?

I made some changes to use with PostgreSQL.

Code:

class Datatables_model extends CI_Model {

    var $ci;
    var $imported;

    public function __construct() {
        //parent::__construct();
        $this->ci = & get_instance();
    }

    public function generate($table, $columns, $index, $joins, $where, $search, $groupby) {
        $joins = 'inner join pessoa_fisica on (pessoa.id_pessoa = pessoa_fisica.id_pessoa)';
        $sLimit = $this->get_paging();
        $sOrder = $this->get_ordering($columns);
        $sWhere = $this->get_filtering($columns, $where, $search);
        $rResult = $this->get_display_data($table, $columns, $sWhere, $sOrder, $sLimit, $joins, $where);
        $tamanho = $this->total_rows($table);
        $rResultFilterTotal = $this->get_data_set_length($table, $sLimit,$joins);
        $aResultFilterTotal = $rResultFilterTotal->result_array();
        $iFilteredTotal = $tamanho;
        $rResultTotal = $this->get_total_data_set_length($table, $index, $sWhere, $joins, $where);
        $aResultTotal = $rResultTotal->result_array();
        $iTotal = $aResultTotal;
        return $this->produce_output($columns, $iTotal, $iFilteredTotal, $rResult);
    }

    protected function get_paging() {

        if ($this->ci->input->post("iDisplayStart") && $this->ci->input->post("iDisplayLength") !== "-1") {

            $sLimit = "LIMIT " . $this->ci->input->post("iDisplayLength") . " OFFSET " . $this->ci->input->post("iDisplayStart");
        } else {

            $iDisplayLength = $this->ci->input->post("iDisplayLength");
            if (empty($iDisplayLength)) {
                $sLimit = "LIMIT " . " 10 OFFSET  0 ";
            } else {

                $sLimit = "LIMIT " . $iDisplayLength . " OFFSET " . $this->ci->input->post("iDisplayStart");
            }
        }
        return $sLimit;
    }

    protected function get_ordering($columns) {
        $sOrder = "";

        if ($this->ci->input->post("iSortCol_0")!== NULL) {
            $sOrder = "ORDER BY ";

            for ($i = 0; $i < intval($this->ci->input->post("iSortingCols")); $i++)
                $sOrder .= $columns[intval($this->ci->input->post("iSortCol_" . $i))] . " " . $this->ci->input->post("sSortDir_" . $i) . ", ";

            $sOrder = substr_replace($sOrder, "", -2);
        }
        return $sOrder;
    }


    protected function get_filtering($columns, $where, $search) {
        $sWhere = "";

        if ($this->ci->input->post("sSearch") != '') {
            $sWhere = "WHERE ";
            for ($i = 0; $i < count($columns); $i++)
                $sWhere .= $columns[$i] . " ILIKE '%" . $this->ci->input->post("sSearch") . "%' OR ";

            $sWhere = substr_replace($sWhere, "", -3);
        }
        if ($sWhere == '') {
            if ($where !== '') {
                $where = 'WHERE ' . $where;
            }
        }
        return $sWhere . $where;
    }

    protected function get_display_data($table, $columns, $joins, $sWhere, $sOrder, $sLimit) {
        return $this->ci->db->query
                ('
        SELECT ' . str_replace(" , ", " ", implode(", ", $columns)) . '
        FROM ' . $table . ' ' . $joins . ' ' . $sWhere . ' ' . $sOrder . ' ' . $sLimit . ' ');
    }

    public function total_rows($table) {
        $sql = "select count(*) as qtd from $table ";
        $res = $this->db->query($sql);
        $res = $res->row();
        return $res->qtd;
    }

    protected function get_data_set_length($table, $joins, $sLimit) {
        $sql = 'select count(*) from ' . $table .' '.$joins. ' ' . $sLimit;
        $res = $this->db->query($sql);
        return $res;
    }

    protected function get_total_data_set_length($table, $index, $sWhere) {
        return $this->ci->db->query
                ('
        SELECT COUNT(' . $index . ')
        FROM ' . $table . '
        ' . $sWhere . '
      ');
    }

    protected function produce_output($columns, $iTotal, $iFilteredTotal, $rResult) {
        $aaData = array();

        foreach ($rResult->result_array() as $row_key => $row_val) {
            foreach ($row_val as $col_key => $col_val) {
                if ($row_val[$col_key] == "version")
                    $aaData[$row_key][$col_key] = ($aaData[$row_key][$col_key] == 0) ? "-" : $col_val;
                else {
                    switch ($row_val[$col_key]) {
                        default: $aaData[$row_key][] = $col_val;
                            break;
                    }
                }
            }
        }

        $sOutput = array
            (
            "sEcho" => intval($this->ci->input->post("sEcho")),
            "iTotalRecords" => $iTotal,
            "iTotalDisplayRecords" => $iFilteredTotal,
            "aaData" => $aaData
        );
        return json_encode($sOutput);
    }
}