How to use form_validation library rules for AJAX requests - ajax

Question

One of my forms uses AJAX to send data. Since my page never reloads because of AJAX, is there a way I can still make use of form_validation to validate and output which fields are wrong? The url my form sends to using jquery is contact/ajax_send.
The entire AJAX works fine except I haven't inserted any validation yet.

Answer 1

Since you are using ajax to send the data, what you can do is, simply add the form_validation code calls before inserting into the database.
If there are any validation errors, you can either return the error messages as json response to the front end to display the error messages.

Answer 2

The form validation library assigns all errors that occurred to a private array called _error_array, but does not expose it or provide documentation on it (notice the first underscore?). Just return a json encoded object of the errors in the controller:
echo json_encode($this->form_validation->_error_array);
If you wish, you can extend CodeIgniter's form validation library, perhaps returning FALSE instead of an empty array... or whatever you see fit:
/* libraries/MY_Form_validation.php */
<?php
class MY_Form_validation extends CI_Form_validation
{
function __construct($config = array())
{
parent::__construct($config);
}
function error_array()
{
if (count($this->_error_array) === 0) return FALSE;
else return $this->_error_array;
}
}
Now, drop the initial underscore in the controller:
echo json_encode($this->form_validation->error_array);
Then decode and display errors on the client.

Answer 3

I found a method, thanks in part to Jordan's answer. This returns an array containing the names of the fields which have errors.
// library/MY_Form_validation.php
class MY_Form_validation extends CI_Form_validation {
public function get_field_data(){
return count($this->_field_data) ? $this->_field_data : FALSE;
}
}
// Controller file
$field_data = $this->form_validation->get_field_data();
foreach($field_data as $key=>$val){
if($key == '__proto__') break;
foreach($val as $k=>$v){
if($k == 'error' && !empty($v)) $errors[] = $key;
}
}
$return = array('success'=>FALSE, 'errors'=>$errors);
The above code checks the error key whether it's empty or not. Empty values mean that it passed the CI validation while none empty values would contain the string you see when you use validation_errors(). Since I'm after those fields which have errors, I only needed to see which values are not empty disregardig those which are.