app/Http/Middleware/UseLanguage.php
<?php
/**
* webtrees: online genealogy
* Copyright (C) 2023 webtrees development team
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <https://www.gnu.org/licenses/>.
*/
declare(strict_types=1);
namespace Fisharebest\Webtrees\Http\Middleware;
use Fisharebest\Localization\Locale;
use Fisharebest\Localization\Locale\LocaleInterface;
use Fisharebest\Webtrees\I18N;
use Fisharebest\Webtrees\Module\LanguageEnglishUnitedStates;
use Fisharebest\Webtrees\Module\ModuleLanguageInterface;
use Fisharebest\Webtrees\Services\ModuleService;
use Fisharebest\Webtrees\Session;
use Fisharebest\Webtrees\Site;
use Generator;
use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use Psr\Http\Server\MiddlewareInterface;
use Psr\Http\Server\RequestHandlerInterface;
use function is_string;
/**
* Middleware to select a language.
*/
class UseLanguage implements MiddlewareInterface
{
private ModuleService $module_service;
/**
* @param ModuleService $module_service
*/
public function __construct(ModuleService $module_service)
{
$this->module_service = $module_service;
}
/**
* @param ServerRequestInterface $request
* @param RequestHandlerInterface $handler
*
* @return ResponseInterface
*/
public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
{
foreach ($this->languages($request) as $language) {
if ($language instanceof ModuleLanguageInterface) {
I18N::init($language->locale()->languageTag());
Session::put('language', $language->locale()->languageTag());
break;
}
}
return $handler->handle($request);
}
/**
* The language can be chosen in various ways.
* Language module names have the form "language-<code>>".
*
* @param ServerRequestInterface $request
*
* @return Generator<ModuleLanguageInterface|null>
*/
private function languages(ServerRequestInterface $request): Generator
{
$languages = $this->module_service->findByInterface(ModuleLanguageInterface::class, true);
// Last language used
yield $languages
->first(static fn (ModuleLanguageInterface $module): bool => $module->locale()->languageTag() === Session::get('language'));
// Browser negotiation
$locales = $this->module_service->findByInterface(ModuleLanguageInterface::class, true)
->map(static fn (ModuleLanguageInterface $module): LocaleInterface => $module->locale());
$default = Locale::create(Site::getPreference('LANGUAGE'));
$locale = Locale::httpAcceptLanguage($request->getServerParams(), $locales->all(), $default);
yield $languages
->first(static fn (ModuleLanguageInterface $module): bool => $module->locale()->languageTag() === $locale->languageTag());
// No languages enabled? Use en-US
yield new LanguageEnglishUnitedStates();
}
}