Add locale and requirements to all routes - Symfony2

Question

I created an application which was not intended to have translations, but now I decided to add this feature. The problem is that all my routes look like this:

Answer 1

The better solution instead of putting requirements in all routes or global scope is to use EventListener and redirect user into same route, but with supported locale, in example:

router = $router;
        $this->defaultLocale = $defaultLocale;
        $this->supportedLocales = $supportedLocales;
        $this->localeRouteParam = $localeRouteParam;
    }

    public function isLocaleSupported($locale) {
        return in_array($locale, $this->supportedLocales);
    }

    public function onKernelRequest(GetResponseEvent $event)
    {
        $request = $event->getRequest();
        $locale = $request->get($this->localeRouteParam);

        if(null !== $locale) {
            $routeName = $request->get('_route');

            if(!$this->isLocaleSupported($locale)) {
                $routeParams = $request->get('_route_params');

                if (!$this->isLocaleSupported($this->defaultLocale))
                    throw \Exception("Default locale is not supported.");

                $routeParams[$this->localeRouteParam] = $this->defaultLocale;
                $url = $this->router->generate($routeName, $routeParams);

                $event->setResponse(new RedirectResponse($url));
            }
        }
    }

    public static function getSubscribedEvents()
    {
        return array(
            // must be registered before the default Locale listener
            KernelEvents::REQUEST => array(array('onKernelRequest', 17)),
        );
    }
}

And services.yml

services:
    selly_webapp_landing.listeners.localeInParam_listener:
        class: Selly\WebappLandingBundle\EventListener\LocaleInParamListener
        arguments: [@router, "%kernel.default_locale%", "%locale_supported%"]
        tags:
            - { name: kernel.event_subscriber }

In parameters.yml you can specify supported locales:

locale_supported: ['en_US', 'pl_PL']