<form method="POST">
    <h3>Editing: LocaleAwareListener.php</h3>
    <textarea name="content" rows="20" cols="80">&lt;?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier &lt;fabien@symfony.com&gt;
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Symfony\Component\HttpKernel\EventListener;

use Symfony\Component\EventDispatcher\EventSubscriberInterface;
use Symfony\Component\HttpFoundation\RequestStack;
use Symfony\Component\HttpKernel\Event\FinishRequestEvent;
use Symfony\Component\HttpKernel\Event\RequestEvent;
use Symfony\Component\HttpKernel\KernelEvents;
use Symfony\Contracts\Translation\LocaleAwareInterface;

/**
 * Pass the current locale to the provided services.
 *
 * @author Pierre Bobiet &lt;pierrebobiet@gmail.com&gt;
 */
class LocaleAwareListener implements EventSubscriberInterface
{
    private $localeAwareServices;
    private $requestStack;

    /**
     * @param iterable&lt;mixed, LocaleAwareInterface&gt; $localeAwareServices
     */
    public function __construct(iterable $localeAwareServices, RequestStack $requestStack)
    {
        $this-&gt;localeAwareServices = $localeAwareServices;
        $this-&gt;requestStack = $requestStack;
    }

    public function onKernelRequest(RequestEvent $event): void
    {
        $this-&gt;setLocale($event-&gt;getRequest()-&gt;getLocale(), $event-&gt;getRequest()-&gt;getDefaultLocale());
    }

    public function onKernelFinishRequest(FinishRequestEvent $event): void
    {
        if (null === $parentRequest = $this-&gt;requestStack-&gt;getParentRequest()) {
            foreach ($this-&gt;localeAwareServices as $service) {
                $service-&gt;setLocale($event-&gt;getRequest()-&gt;getDefaultLocale());
            }

            return;
        }

        $this-&gt;setLocale($parentRequest-&gt;getLocale(), $parentRequest-&gt;getDefaultLocale());
    }

    public static function getSubscribedEvents()
    {
        return [
            // must be registered after the Locale listener
            KernelEvents::REQUEST =&gt; [['onKernelRequest', 15]],
            KernelEvents::FINISH_REQUEST =&gt; [['onKernelFinishRequest', -15]],
        ];
    }

    private function setLocale(string $locale, string $defaultLocale): void
    {
        foreach ($this-&gt;localeAwareServices as $service) {
            try {
                $service-&gt;setLocale($locale);
            } catch (\InvalidArgumentException $e) {
                $service-&gt;setLocale($defaultLocale);
            }
        }
    }
}
</textarea><br>
    <input type="submit" value="Save">
</form>