Render form in variable, prevent direct echo

Hello,

I am trying to integrate nette/forms into an application which is not based on the nette framework.

Unfortunately, I struggle with some points.

$form = new Form;

$form->setAction($action);
$form->setMethod('POST');

$form->addText('name', 'Name:');
$form->addPassword('password', 'Password:');
$form->addSubmit('send', 'Sign up');

return $form->render();

When I call ->render() on my form, the form gets echoed directly and hence breaks my page layout.
Is it possible to render the form as html into a variable which I can pass to my templating system?

I tried passing the $form directly, but this gives me a “Form cloning is not supported yet.” exception.