abstract class FormHandler extends Nette\Object
{
    public function attach(Form $form)
    {
        $that = $this;
        if (method_exists($this, 'handleSuccess')) {
            $form->onSuccess[] = function (Form $form) use ($that) {
                if (!$form->isValid()) return;
                try {
                    $that->handleSuccess($form->getValues());

                } catch (ValidationError $e) {
                    foreach ($e->errors as $error) {
                        $control = $error['control'] ? $form->getComponent($error['control']) : $form;
                        $control->addError($error['message']);
                    }
                }
            };
        }
        if (method_exists($this, 'handleError')) {
            $form->onError[] = function (Form $form) use ($that) {
                $that->handleError($form->getValues());
            };
        }
    }

    public function attachButton(SubmitButton $button)
    {
        $that = $this;
        if (method_exists($this, 'handleClick')) {
            $button->onClick[] = function (SubmitButton $button) use ($that) {
                $form = $button->form;
                try {
                    $that->handleClick($form->getValues());

                } catch (ValidationError $e) {
                    foreach ($e->errors as $error) {
                        $control = $error['control'] ? $form->getComponent($error['control']) : $form;
                        $control->addError($error['message']);
                    }
                }
            };
        }
        if (method_exists($this, 'handleError')) {
            $button->onInvalidClick[] = function (SubmitButton $button) use ($that) {
                $that->handleError($form->getValues());
            };
        }
    }
}

class RegistrationHandler extends FormHandler
{
    public $onFoo = array();
    public $onBar = array();

    public function handleSuccess($values)
    {
        $error = new ValidationError;

        if ($values->name != "Valid") {
            $error->addError("Name is invalid", 'name');
        }

        $error->assertValid();
        $this->model->save($values);
    }
}


class ValidationError extends \Exception
{
    public $errors = array();

    public function addError($error, $controlName = NULL)
    {
        $this->errors[] = array('message' => $error, 'control' => $controlName);
        return $this;
    }

    public function assertValid()
    {
        if ($this->errors) { throw $this; }
    }
}

$form = new Form;
$handler = new RegistrationHandler();
$handler->attach($form);
$handler->attachButton($form->addSubmit('send', "Odeslat"));