Form Validation Individual Field Validation

It would work the same, as referenced here: https://codeigniter.com/user_guide/libra...rule-group

You'd just skip the set rules part and, in the config file, define the rule to use and then call that rule group specifically:

PHP Code:

if (! $this->form_validation->run('check_ajax_username')) {
    echo form_error('username');
} 


Best regards,
José Postiga
Senior Backend Developer