symfony 2 set locale based on user preferences stored in DB - php

Question

I am trying to set the locale based on the current user's preferences which are stored in the DB.
Our User class therefore has a getPreferredLanguage which returns a locale identify ('en', 'fr_FR', etc.).
I've considered the following approach:
register a "locale" listener service that subscribes to the KernelEvents::REQUEST event.
this service has access to the security context (via its constructor)
this service's onKernelRequest method attempts to get the user from the security context, get the user's preferred locale, and set it as the request's locale.
Unfortunately, this doesn't work. When the "locale" listener service's onRequestEvent method is invoked, the security context does not have a token. It seems that the context listener is invoked at a very late stage (with a priority of 0), and it is impossible to tell my "locale" listener to run before the security context.
Does anyone know how to fix this approach, or suggest another one?

Answer 1

You may be interested in the locale listener, which I posted in this answer: Symfony2 locale detection: not considering _locale in session
Edit: If a user changes his language in the profile, it's no problem. You can hook into profile edit success event if you're are using FOSUserBundle (master). Otherwise in your profile controller, if you're using a self made system. Here is a example for FOSUserBundle:
<?php
namespace Acme\UserBundle\EventListener;
use FOS\UserBundle\Event\FormEvent;
use FOS\UserBundle\FOSUserEvents;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
class ChangeLanguageListener implements EventSubscriberInterface
{
public static function getSubscribedEvents()
{
return array(
FOSUserEvents::PROFILE_EDIT_SUCCESS => 'onProfileEditSuccess',
);
}
public function onProfileEditSuccess(FormEvent $event)
{
$request = $event->getRequest();
$session = $request->getSession();
$form = $event->getForm();
$user = $form->getData();
$lang = $user->getLanguage();
$session->set('_locale', $lang);
$request->setLocale($lang);
}
}
and in the services.yml
services:
acme.change_language:
class: Acme\UserBundle\EventListener\ChangeLanguageListener
tags:
- { name: kernel.event_subscriber }
for multiple sessions in multiple browser is no problem, as every new session requires a new login. Hmm, ok, not after changing the language, as only the current session would be updated. But you can modify the LanguageListener to support this.
And the case if an admin changes the language should be insignificant.

Answer 2

If you reach this answer through Google, I am currently using this solution.
<?php
namespace App\EventSubscriber;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpKernel\KernelEvents;
use Symfony\Component\HttpKernel\Event\ControllerEvent;
use Symfony\Component\Security\Core\Security;
use Symfony\Contracts\Translation\TranslatorInterface;
class SetLocaleEventSubscriber implements EventSubscriberInterface
{
private Security $security;
private TranslatorInterface $translator;
public function __construct(Security $security, TranslatorInterface $translator)
{
$this->security = $security;
$this->translator = $translator;
}
public static function getSubscribedEvents()
{
return [
KernelEvents::CONTROLLER => [
['setLocale', 1]
]
];
}
public function setLocale(ControllerEvent $event)
{
if (!$event->isMasterRequest()) {
return;
}
$request = $event->getRequest();
/**
* #var \App\Entit\User
*/
$user = $this->security->getUser();
if ($user) {;
$request->setLocale($user->getLocale());
$this->translator->setLocale($user->getLocale());
}
}
}

Answer 3

In order to achieve this, you need to setup an event subscriber on the Kernel::REQUEST event with a higher priority than the default Locale listener as indicated in the documentation
At this time, you will unfortunately not be able to access to the current logged in user because this is something set in another Symfony event triggered after the Locale listener.
However, you can access to the session.
The solution is to save the user's locale in the session just after a successful login, and then set the locale in the request from the session.
// src/EventSubscriber/UserLocaleSubscriber.php
namespace App\EventSubscriber;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpFoundation\RequestStack;
use Symfony\Component\Security\Http\Event\InteractiveLoginEvent;
use Symfony\Component\Security\Http\SecurityEvents;
/**
* Stores the locale of the user in the session after the
* login. This can be used by the LocaleSubscriber afterwards.
*/
class UserLocaleSubscriber implements EventSubscriberInterface
{
private $requestStack;
public function __construct(RequestStack $requestStack)
{
$this->requestStack = $requestStack;
}
public function onInteractiveLogin(InteractiveLoginEvent $event)
{
$user = $event->getAuthenticationToken()->getUser();
if (null !== $user->getLocale()) {
$this->requestStack->getSession()->set('_locale', $user->getLocale());
}
}
public static function getSubscribedEvents()
{
return [
SecurityEvents::INTERACTIVE_LOGIN => 'onInteractiveLogin',
];
}
}
// src/EventSubscriber/LocaleSubscriber.php
namespace App\EventSubscriber;
use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpKernel\Event\RequestEvent;
use Symfony\Component\HttpKernel\KernelEvents;
class LocaleSubscriber implements EventSubscriberInterface
{
public function onKernelRequest(RequestEvent $event)
{
$request = $event->getRequest();
if ($request->getSession()) {
// Set user's locale from session
if ($locale = $request->getSession()->get('_locale')) {
$request->setLocale($locale);
}
}
}
public static function getSubscribedEvents()
{
return [
// must be registered before (i.e. with a higher priority than) the default Locale listener
KernelEvents::REQUEST => [['onKernelRequest', 20]],
];
}
}