localeForLanguage example

// Set global variables $app->view()->setData('version', $container->offsetGet('shopware.version'));
$app->view()->setData('t', $translationService);
$app->view()->setData('menuHelper', $menuHelper);
$app->view()->setData('selectedLanguage', $selectedLanguage);
$app->view()->setData('translations', $translations);
$app->view()->setData('baseUrl', Utils::getBaseUrl($app));
$app->view()->setData('app', $app);
$app->view()->setData('error', false);
$app->view()->setData('parameters', $_SESSION['parameters']);

$app->setCookie('installed-locale', localeForLanguage($selectedLanguage), time() + 7200, '/');

$app->add(new XssMiddleware());

$app->error(function DException $e) use ($app) {
    if (!$app->request()->isAjax()) {
        throw $e;
    }

    $response = $app->response();
    $data = [
        'code' => $e->getCode(),