Generate new CSRF token without reloading the entire form

Question

If a user gets logged out (due to session expiration or for other reasons) in the background while using my Symfony2 application, I have implemented a JS layer appearing on

Answer 1

Assuming that you use default CSRF Provider, in your AJAX controller you can get your CSRF Provider service and "ask" it to regenerate token:

Symfony 2.3 (and prior)

/** @var \Symfony\Component\Form\Extension\Csrf\CsrfProvider\SessionCsrfProvider $csrf */
$csrf = $this->get('form.csrf_provider');
$token = $csrf->generateCsrfToken($intention); 

return new Response($token);

---

Symfony 2.4

/** @var \Symfony\Component\Security\Csrf\CsrfTokenManagerInterface $csrf */
$csrf = $this->get('security.csrf.token_manager');
$token = $csrf->refreshToken($intention);

return new Response($token);