hopefully i didn’t mix up too much :P
but might be slightly more understandable than google translate.

btw:
http://dict.leo.org/forum/viewUnsolvedquery.php?idThread=176140&idForum=1&lp=ende&lang=de

Max was kind enough translating the article, thanks for the effort! Feel free to reuse it in any way, and thanks for your inquiry :)

The Security Bundle is a bit magical. You have to define a HTML-Form, the rest gets configured somehow elsewhere (post-parameter names like “_username”, “_password” etc., the referrer redirect, Remember-Me functionality etc., all that is handled by the firewall. You just have to define a Login-Route, a Stub-Controller + Action-Callable (which actually never gets executed, as the firewall comes first), done.

Very comfortable – as long as you don’t start asking questions. But how do you execute functions directly after the login, without altering the Security-Bundle Code?

Most of the time you’ll try to find a Hook, Entry-Point or Config-Variable.
In Symfony 2 of course, you’ll be looking for events, but the Documentation does not say anything about that.
So back to the source-code.
There has to be a possibility – and there is. It’s to be found in the AbstractAuthentificationListener:

vendorsymfonysrcSymfonyComponentSecurityHttpFirewallAbstractAuthentificationListener.php

namespace SymfonyComponentSecurityHttpFirewall;

//...

abstract class AbstractAuthenticationListener implements ListenerInterface
{
    // ...
    private function onSuccess(GetResponseEvent $event, Request $request, TokenInterface $token)
    {
        if (null !== $this->logger) {
            $this->logger->info(sprintf('User "%s" has been authenticated successfully', $token->getUsername()));
        }

        $this->securityContext->setToken($token);

        $session = $request->getSession();
        $session->remove(SecurityContextInterface::AUTHENTICATION_ERROR);
        $session->remove(SecurityContextInterface::LAST_USERNAME);

        if (null !== $this->dispatcher) {
            $loginEvent = new InteractiveLoginEvent($request, $token);
            $this->dispatcher->dispatch(SecurityEvents::INTERACTIVE_LOGIN, $loginEvent);
        }

        if (null !== $this->successHandler) {
            $response = $this->successHandler->onAuthenticationSuccess($request, $token);
        } else {
            $response = $this->httpUtils->createRedirectResponse($request, $this->determineTargetUrl($request));
        }

        if (null !== $this->rememberMeServices) {
            $this->rememberMeServices->loginSuccess($request, $response, $token);
        }

        return $response;
    }

The class is just printed as an excerpt here, interesting are lines 233 and 238 in the original source.

line 233 and the following notifies all AbstractAuthentificationListener which listen to SecurityEvents::INTERACTIVE_LOGIN, if a Event-Dispatcher is defined. (Which can be expected in the sf2 standard distribution)

line 238 is something special, a “Security-Bundle-specific” Event.
there’s a possibility to set a DIC-Service in the firewall settings in the security.yml via “success_handler”.

Man hat die Möglichkeit, in der jeweiligen Firewall-Einstellung für den Form-Login in der security.yml mit success_handler which implements SymfonyComponentSecurityHttpAuthenticationAuthenticationSuccessHandlerInterface.

This looks like this:

      secured_area:
            pattern:    ^/demo/secured/
            form_login:
                check_path: /demo/secured/login_check
                login_path: /demo/secured/login
                success_handler: dvlp_core.login_success_handler

Implementation of the Callback Method onAuthenticationSuccess(Request $request, TokenInterface $token) of the Interface is not that easy though, as it expects an instance of SymfonyComponentHttpFoundationResponse as return value,
which you have to configure by yourself (including Redirect-Adress, referrer-logic and processing of the user config)

That’s why we’ll leave that alone for the moment and use the Event-Dispatcher, to hook into the login.
Therefor we define a new Server in one of our Bundles and tag it as Eventlistener:

Resourcesconfigservices.xml:

    <parameters>
        <parameter key="dvlp_core.event_listener.class">DvlpCoreBundleEventListener</parameter>
    </parameters>
    <service id="dvlp_core.event_listener" class="%dvlp_core.event_listener.class%">
        <tag name="kernel.event_listener" event="security.interactive_login" method="onSecurityInteractiveLogin" />
    </service>

Now implement the listener. The listener should set the Session-Locale “on login” in the locale-settings of the current (DB)-User.

DvlpCoreBundleEventListener.php:

class EventListener
{
    public function onSecurityInteractiveLogin(InteractiveLoginEvent $event)
    {
        $token = $event->getAuthenticationToken();
        $session = $event->getRequest()->getSession();
        $session->setLocale($token->getUser()->getLocale());
    }
}

And That’s that -Events to the Rescue.
Unfortunately there seems to be not so much documentation on that atm.
But I’ll be happy to be proven wrong.

Have fun trying that at home.