<?php  if ( ! defined(‘BASEPATH’)) exit(‘No direct script access allowed’);
class MY_Form_validation extends CI_Form_validation {
 
        function required_file($str)
        {
                if (!isset($_FILES[$str])) return FALSE;
                if ($_FILES[$str][’size’] == 0)
                {
                        return FALSE;
                }
                return TRUE;
        }
 
        function valid_file_types($str, $vals)
        {
                if (!isset($_FILES[$str])) return FALSE;
                if (isset($_FILES[$str]) AND $_FILES[$str][’size’] > 0)
                {
                        $allowed_types = explode(‘,’, $vals);
                        require_once(APPPATH.‘config/mimes’.EXT);
                        foreach ($allowed_types as $ext)
                        {
                                $ext = trim(strtolower($ext));
                                $mime = $mimes[$ext];
                                if (is_array($mime))
                                {
                                        foreach ($mime as $m)
                                        {
                                                $allows[] = $m;
                                        }
                                }
                                else
                                {
                                        $allows[] = $mime;
                                }
                        }
                        $file_info = getimagesize($_FILES[$str][‘tmp_name’]);
                        $file_mime = $file_info[‘mime’];
 
                        if (!in_array($file_mime, $allows))
                        {
                                return FALSE;
                        }
                }
                return TRUE;
        }
 
}
?>

<?php
#### Old Code ####
/* ——— Extended ———-*/
$lang[‘required_file’] = "%s bla bla bla";
$lang[‘valid_file_types’] = "%s %s bla bla bla";
?>

<form method="post" action="/path/form/save" multipart/form-data">
<div id="hidden_fields">
  <input type="hidden" name="file_checker" value="file_upload" />
</div>
<label><input type="file" name="file_upload" /></label>
<lable><input type="submit" value="upload" /></label>
</form>
 

function some_method()
{
  $this->load->library(‘form_validation’);
  $this->form_validation->set_rules(‘file_checker’, ‘Form Name Here’, ‘required|required_file|valid_file_types[jpg,jpeg,gif,png]‘);
  if ($this->form_validation->run() == TRUE)
  {
     // do something for success case.
  }
  else
  {
    // do something for handler errors
  }
}