Load existing files in blueimp jQuery file upload by id

hi iam trying to use blueimp jQuery file upload with codeigniter but i need to load existing files by id inserted in database

this is function in my controller

 public function get_files()
{

    $last = $this->uri->total_segments();
    $record_num = $this->uri->segment($last);

    if (is_numeric($record_num) == TRUE) {

    $upload_path_url = base_url() . 'uploads/';
    $config['upload_path'] = FCPATH . 'uploads/';
    $config['allowed_types'] = 'jpg|jpeg|png|gif';
    $config['max_size'] = '30000';

        $existingFiles = get_dir_file_info($config['upload_path']);
        $foundFiles = array();
        $f=0;
        foreach ($existingFiles as $fileName => $info) {
          if($fileName!='thumbs'){//Skip over thumbs directory
            //set the data for the json array   
            $foundFiles[$f]['name'] = $fileName;
            $foundFiles[$f]['size'] = $info['size'];
            $foundFiles[$f]['url'] = $upload_path_url . $fileName;
            $foundFiles[$f]['thumbnailUrl'] = $upload_path_url . 'thumbs/' .                 $fileName;
            $foundFiles[$f]['deleteUrl'] = base_url() . 'http://ift.tt/2akxtQW' . $fileName;
            $foundFiles[$f]['deleteType'] = 'DELETE';
            $foundFiles[$f]['error'] = null;

            $f++;
          }
        }
        $this->output
        ->set_content_type('application/json')
        ->set_output(json_encode(array('files' => $foundFiles)));

and in main.js

// Load existing files:
    $('#fileupload').addClass('fileupload-processing');
    $.ajax({
        // Uncomment the following to send cross-domain cookies:
        //xhrFields: {withCredentials: true},
        // url: $('#fileupload').fileupload('option', 'url'),
        url: 'http://localhost/mysite/index.php/App/controll/get_files',
        dataType: 'json',
        context: $('#fileupload')[0]
    }).always(function () {
        $(this).removeClass('fileupload-processing');
    }).done(function (result) {
        $(this).fileupload('option', 'done')
            .call(this, $.Event('done'), {result: result});
    });

but this if statement if (is_numeric($record_num) == TRUE) didn't work