retrieve data from .post

Question

I'm using codeigniter, I had a problem to process a data using jQuery $.post function. I want to send a value such as subjectid to ajax_get_subject_credit function and retrieve another field within same database table. The result shows on another text field. Here is my code.

View:

$.post('<?php echo site_url('academic/ajax_get_subject_credit'); ?>', {'subjectid':subjectid}, function(data){

        $('#chours' + id).val(data); });

This get a value from drop-down and I want to make a text field automatic populate from drop-down. #chours is a text field ID.

Controller:

function ajax_get_subject_credit($result)
{
    $this->db->select('subjectid, subjectcredit');
    $query = $this->db->get('ref_subject');
    $result = $query->result_array();
    $query->free_result();
    $subjectid = array();
    foreach($result as $row)
    {
        $result = $result + array($row['subjectid'] => $row['subjectcredit']);
    }
    return $result;
}

Modified In Controller

I also tried using this statement in controller for direct calling the field but still no success :

function ajax_get_subject_credit($subjectid)
{
    $this->db->select('subjectid, subjectcredit');
    $this->db->where('subjectid',$subjectid);
    $query = $this->db->get('ref_subject');
    $credithour = $query->row()->subjectcredit;
    $query->free_result();
    echo $credithour;
}

Answer 1

I am going to provide a general example here

in view file

$.post('<?php echo site_url("test/test"); ?>', {'id':1}, function(response){

   if(response.success)
   {
     alert(response.message);
   } else
   {
     alert('Something went wrong!!');
   }
}, 'json');

in controller Test.php

function test()
{
  $id = $this->input->post('id');

  //do additional stuff

  $result = 'i am coming right out of controller!! ';

  echo json_encode(array('success' => true, 'message' => $result));
}

Answer 2

Dont use return to return value to AJAX. use echo

change this,

return $result;

to

echo $result;

Answer 3

If you want your method to return an array that the javascript can use to populate a dropdown, you probably don't want to return a string.

Try something like this:

function ajax_get_subject_credit()
{
    $query = $this->db->select('subjectid, subjectcredit')->get('ref_subject');

    $result = $query->result();

    $out = array();
    foreach($result as $row) {
        $out[$row->subjectid] = $row->subject_credit;
    }

    header('Content-Type: application/json');
    echo json_encode($out);

}

This will return a JSON array to your view, which your javascript method can use to populate the dropdown with values and labels.

Answer 4

Here is my Result:

In View :

function subjectid_change(id, subjectid){
    //Set value
    setValue(id, subjectid);

    $.post('<?php echo site_url('academic/ajax_get_subject_credit'); ?>', {'subjectid':subjectid}, function(response){

        if(response.success)
        {
          $('#chours' + id).val(response.value);
        } else
        {
          alert('Something went wrong!!');
        }
    }, 'json'); }

And my controller :

function ajax_get_subject_credit()
{
    //Get Post Value
    $subjectid = $this->input->post('subjectid');
    //Select subjectid,subjectcredit FROM
    $this->db->select('subjectid, subjectcredit');
    //Where subjectid = 'subjectid'
    $this->db->where('subjectid',$subjectid);
    //Database name
    $query = $this->db->get('ref_subject');

    $credithour = $query->row()->subjectcredit;
    $query->free_result();
    $result = $credithour;

    echo json_encode(array('success' => true, 'value' => $result));
}

Thanks to everybody who helped me.