parsing Accept-Language and setting Content-Language headers in Silex

silex-language-codes.php

<?php

require_once __DIR__ . '/../vendor/autoload.php';

use Symfony\Component\HttpFoundation\JsonResponse;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;

$app = new Silex\Application();

$app->before(function (Request $request) use ($app) {
    $locale = $request->getPreferredLanguage([
        'ko', 'en', 'de', 'pt', 'pt_BR', 'fr', 'ja', 'zh', 'zh-Hans-CH',
    ]);

    $app['locale'] = $locale;
    $app['contentLanguage'] = str_replace('_', '-', $locale);
});

$app->after(function (Request $request, Response $response) use ($app) {
    $response->headers->set('Content-Language', $app['contentLanguage']);
});

$app->get('/', function () use ($app) {
    return new JsonResponse(
        [
            'locale' => $app['locale'],
            'contentLanguage' => $app['contentLanguage']
        ]
    );
});

$app->run();