This is extended version of Phalcon\Validation\Validator\PresenceOf with Validator Trait implemented.
namespace Foo\Forms;
use Phalcon\Forms\Element\Text;
use Vegas\Validation\Validator\PresenceOf;
class Bar extends \Vegas\Forms\Form
{
public function initialize()
{
$username = new Text('username');
$username->addValidator(new PresenceOf());
$this->add($username);
// ...
}
}