Help with ajax autocomplete by querying the database

The question what comes in my mind is whether my query is returning the values from the database or did I miss anything in my code. I have been trying to figure it out but I am unable to understand.

print_r($tagnames) doesn't print anything on the screen.

This code is part of the controller

function get_Names() {
            // Convert the string to the lowercase
            $q = strtolower($this->input->post('q', TRUE));
            if(!$q) {
                return;

            }
            $tagnames[] = $this->autocomplete_model->getData();
            print_r($tagnames);

            echo json_encode($tagnames);

        }

I have autocomplete_model.php and this code is part of the model

class Autocomplete_model extends CI_Model {

    public function __construct() {
        parent::__construct();
    }

    function getData() {
        $q = $this->db->query("SELECT * FROM tags");
        if($q->num_rows() > 0) {
            foreach($q->result() as $row) {
                $data[] = $row->tag_name;
            }
            return $data;
        }
    }
}

I have the following code in my view

$(document).ready(function() {
    $(function() {
        $( "#tagname" ).autocomplete({
                    source: function(request, response) {
                        $.ajax({ url: "<?php echo site_url('generator/get_Names'); ?>",
                        data: { term: $("#tagname").val()},
          开发者_运维问答              dataType: "json",
                        type: "POST",
                        success: function(data){
                                response(data);
                        }
                    });
        },
        minLength: 2
        });
    });
    });

Thanks in advance.

It looks like your AJAX call is sending "term" as post data but your get_Names() method is looking for a post parameter of "q". Change one of them and I think you should be good.