Get Json data from controller

Question

I need to create dinamic select into my form. I have wrote this code to get it dinamically from my controller (CodeIgniter) that get data from model.

This is the script:

<script type="text/javascript">
   $(document).ready(function(){
                    $("select#regione").change(function(){
                        $.getJSON("http://test:8888/ricerca/test",{id: $(this).val()}, function(dati){
                            var options = '';
                            for (var i = 0; i < dati.length; i++) {
                                options += '<option value="' + dati[i].valore + '">' + dati[i].etichetta + '</option>';
                            }
                            $("#provincia").html(options);
                            $('#provincia option:first').attr('selected', 'selected');
                        });
                    });
                });
            </script>

This is the dropdown form:

<form action="base_url().'ricerca'" method="post">
<select name="regione" id="regione">
<option value="">No option</option>
<option value="Lombardia">Lombardia</option>
<option value="Lazio">Lazio</option>
</select>

<select name="provincia" id="provincia">
</select>
</form>

and this is the controller:

class Ricerca extends CI_Controller
{
 public function test()
{
 $dati = array();
         array_push($dati,array("valore"=>"ciao", "etichetta"=>"ciao"));
         array_push($dati,array("valore"=>"mamma", "etichetta"=>"mamma"));
         return json_encode($dati);
}
}

Before to do my query in the model I would see if my script works but if I select an option in the first select called "Regione" the script does nothing

Answer 1

you have to echo json data from controller function not to return data

public function test()
{
 $dati = array();
         array_push($dati,array("valore"=>"ciao", "etichetta"=>"ciao"));
         array_push($dati,array("valore"=>"mamma", "etichetta"=>"mamma"));
         echo json_encode($dati);
}

or you can do

public function test()
    {
     $dati = array();
             array_push($dati,array("valore"=>"ciao", "etichetta"=>"ciao"));
             array_push($dati,array("valore"=>"mamma", "etichetta"=>"mamma"));
             $this->output
    ->set_content_type('application/json')
    ->set_output(json_encode($dati));
    }