Cannot display returned JSON from a JQUERY AJAX call in CodeIgniter

Question

Im using JQUERY + CodeIgniter. I can't seem to get the returned data to display after an ajax call.

Here is my JQUERY:

  $.post("<?= site_url('plan/get_conflict') ?>", {
    user_id : user_id,
    datetime_from : plan_datetime_start,
    datetime_to : plan_datetime_end,
    json : true
   }, function(data) {
    alert(data);
     }, "json");

Here is my CodeIgniter:

function get_conflict() {
    ...
 log_message("debug","get_conflict(): $result");
 return $result;
}

My logs show:

get_conflict(): {"work_product_name":"Functional Design Document","datetime_start_plan":"2010-04-22 08:00:00","datetime_end_plan":"2010-04-22 09:00:00","overlap_seconds":3600}

Meaning the JSON is being returned correctly. However, the alert(data) nor alert(data.work_product_name) are not displayed.

Any ideas?

Answer 1

Try this

 public function CreateStudentsAjax() {

        $this->load->helper('form');
        $this->load->library('form_validation');
        $this->form_validation->set_error_delimiters('', '');

        $this->form_validation->set_rules('roll', 'Roll Number', 'required');
        $this->form_validation->set_rules('name', 'Name', 'required');
        $this->form_validation->set_rules('phone', 'Phone', 'required');

        if ($this->form_validation->run()) {

            $this->welcome_model->InsertStudents();
            echo json_encode("Oks");
        } else {

            $data = array(
                'roll' => form_error('roll'),
                'name' => form_error('name'),
                'phone' => form_error('phone')
            );

            echo json_encode($data);
        }
    }

and Scripts

<script type="text/javascript">

            $(document).ready(function(){

                $('form').submit(function(){
                    //alert('ok');      
                    $.ajax({
                        url:this.action,
                        type:this.method,
                        data:$(this).serialize(),
                        success:function(data){
                            var obj = $.parseJSON(data);

                            if(obj['roll']!=null)
                            {                               
                                $('#message').text("");
                                $('#message').html(obj['roll']);
                                $('#message').append(obj['name']);
                                $('#message').append(obj['phone']);
                            }
                            else
                            {                               
                                $('#message').text("");
                                $('#message').html(obj); 
                            }

                        },
                        erro:function(){
                            alert("Please Try Again");
                        }                        
                    });
                    return false;
                });                        
            });

Answer 2

You are returning the result... you should be outputting it.

For example

function get_conflict() {
    ...
    log_message("debug","get_conflict(): $result");

    $this->output->set_output( json_encode($result) );
}