<?php

/*
 * This file is part of the Symfony package.
 *
 * (c) Fabien Potencier <fabien@symfony.com>
 *
 * 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\Request;
use Symfony\Component\HttpFoundation\RequestStack;
use Symfony\Component\HttpKernel\Event\FinishRequestEvent;
use Symfony\Component\HttpKernel\Event\KernelEvent;
use Symfony\Component\HttpKernel\Event\RequestEvent;
use Symfony\Component\HttpKernel\KernelEvents;
use Symfony\Component\Routing\RequestContextAwareInterface;

/**
 * Initializes the locale based on the current request.
 *
 * @author Fabien Potencier <fabien@symfony.com>
 *
 * @final
 */
class LocaleListener implements EventSubscriberInterface
{
    public function __construct(
        private RequestStack $requestStack,
        private string $defaultLocale = 'en',
        private ?RequestContextAwareInterface $router = null,
        private bool $useAcceptLanguageHeader = false,
        private array $enabledLocales = [],
    ) {
    }

    public function setDefaultLocale(KernelEvent $event): void
    {
        $event->getRequest()->setDefaultLocale($this->defaultLocale);
    }

    public function onKernelRequest(RequestEvent $event): void
    {
        $request = $event->getRequest();

        $this->setLocale($request);
        $this->setRouterContext($request);
    }

    public function onKernelFinishRequest(FinishRequestEvent $event): void
    {
        if (null !== $parentRequest = $this->requestStack->getParentRequest()) {
            $this->setRouterContext($parentRequest);
        }
    }

    private function setLocale(Request $request): void
    {
        if ($locale = $request->attributes->get('_locale')) {
            $request->setLocale($locale);
        } elseif ($this->useAcceptLanguageHeader) {
            if ($request->getLanguages() && $preferredLanguage = $request->getPreferredLanguage($this->enabledLocales)) {
                $request->setLocale($preferredLanguage);
            }
            $request->attributes->set('_vary_by_language', true);
        }
    }

    private function setRouterContext(Request $request): void
    {
        $this->router?->getContext()->setParameter('_locale', $request->getLocale());
    }

    public static function getSubscribedEvents(): array
    {
        return [
            KernelEvents::REQUEST => [
                ['setDefaultLocale', 100],
                // must be registered after the Router to have access to the _locale
                ['onKernelRequest', 16],
            ],
            KernelEvents::FINISH_REQUEST => [['onKernelFinishRequest', 0]],
        ];
    }
}

.NET Framework

Project Request

ProjectC

Vehicle Maintenance

Movie Navigator

Customers Exchange

ATM

.NET Core

Mail Daemon

Custom

Buns of code

PHP

Mediabox

Loan Castle

Content Management

Laravel

Phone Check

Frontend

Forex Wall

Business projects

Certification Center

Amerikas Auto

Pet projects

Geolocation Assistant

Web Dynamics

Blackball

Good old times

DOS Clock

BrainOut

Airport Administrator

Atomizer

Mediabox