I have a repository demonstrating the standalone usage of the Form component for Symfony 2.1+ with both Twig and PHP as templating engine (check the branches): https://github.com/bschussek/standalone-forms/blob/2.1%2Btwig/src/setup.php
The crucial part is that you shouldn't instantiate FormFactory
objects manually anymore (to give us core developers more flexibility in changing its constructor), but use the Forms
class instead:
$formFactory = Forms::createFormFactoryBuilder()
->addExtension(new CsrfExtension($csrfProvider))
->addExtension(new ValidatorExtension($validator))
->getFormFactory();
A nice side benefit is that your IDE will list you the setters of the form factory builder, showing you what you can configure and how.