vlidation codeigniter 3 callback code example
Example: file form validation codeigniter
if (empty($_FILES['userfile']['name']))
{
$this->form_validation->set_rules('userfile', 'Image', 'required');
}
if (empty($_FILES['userfile']['name']))
{
$this->form_validation->set_rules('userfile', 'Image', 'required');
}