在flexigrid codeigniter中使用搜索和排序功能时没有任何变化

在codeigniter中使用flexigrid库时，我可以很好地显示数据网格，但是当我使用函数排序和搜索时，它不能像我以前希望的那样运行。没有改变，只是加载第一页。问题是在搜索和排序，分页功能是ok的。

可能是我的代码有问题，需要帮助。谢谢。

//Controller
public function daftarKomoditi()
{
    $colModel['dig10'] = array('Kode Komoditi KBKI',120,TRUE,'left',2);
    $colModel['desk10'] = array('Jenis Komoditi',453,TRUE,'left',2);
    $gridParams = array(
        'width' => '600',
        'height' => 'auto',
        'rp' => 10,
        'singleSelect' => true,
        'rpOptions' => '[10,15,20,25,40]',
        'pagestat' => 'Displaying: {from} to {to} of {total} items.',
        'blockOpacity' => 0.5,
        'title' => 'Master Komoditi SHPB 2013',
        'showTableToggleBtn' => false
    );
    $buttons[] = array('Refresh','refresh','test');
    $buttons[] = array('separator');
    $grid_js = build_grid_js('flex2',site_url("/ajax/getKomoditiList"),$colModel,'id','asc',$gridParams,$buttons);
    $data['js_grid'] = $grid_js;  
    $this->load->view('kualitas/komoditi_list',$data);
}
public function getKomoditiList()
{  
    $valid_fields = array('dig10,desk10');
    $this->flexigrid->validate_post('dig10','asc',$valid_fields);
    $records = $this->KualitasModel->getDaftarKomoditi();
    $this->output->set_header($this->config->item('json_header'));
    foreach ($records['records']->result() as $row) {   
        $record_items[] = array($row->dig10,
        $row->dig10,  
        ucfirst(strtolower($row->desk10)),
        );
    }
    $this->output->set_output($this->flexigrid->json_build($records['record_count'],$record_items));        
}
//Model
    function getDaftarKomoditi() //Flexigrid
{
    $table_name = "shpb_mkbki_dig10";
    $this->db->select('*')->from($table_name);
    $this->CI->flexigrid->build_query();
    //Get contents
    $return['records'] = $this->db->get();
    //Build count query
    $this->db->select('count(dig10) as record_count')->from($table_name);
    $this->CI->flexigrid->build_query(FALSE);
    $record_count = $this->db->get();
    $row = $record_count->row();
    //Get Record Count
    $return['record_count'] = $row->record_count;
    //Return all
    return $return;                                        
}