gistfile1.aw

<?php

class SomeController
{
    public function checkoutAction(){
        $user = $this->get('security.context')->getToken()->getUser();
        $errors = $this->get('validator')->validate($user, 'ticket_checkout');
        if(count($errors) > 0) {
            // Add a warning message to the session
            // Redirect user to a profile edit page where he can setup the missing info
            return new RedirectResponse('http://mywebsite.com/update_your_profile');
        }

        // proceed to checkout
    }

}