Symfony2 default locale in routing

Question

I have a problem with routing and the internationalization of my site built with Symfony2.
If I define routes in the routing.yml file, like this:

exampl         


        

Answer 1

I have a full solution to this that I discovered after some research. My solution assumes that you want every route to have a locale in front of it, even login. This is modified to support Symfony 3, but I believe it will still work in 2.

This version also assumes you want to use the browsers locale as the default locale if they go to a route like /admin, but if they go to /en/admin it will know to use en locale. This is the case for example #2 below.

So for example:

1. User Navigates To ->  "/"         -> (redirects)    -> "/en/"
2. User Navigates To ->  "/admin"    -> (redirects)    -> "/en/admin"
3. User Navigates To ->  "/en/admin" -> (no redirects) -> "/en/admin"

In all scenarios the locale will be set correctly how you want it for use throughout your program.

You can view the full solution below which includes how to make it work with login and security, otherwise the Short Version will probably work for you:

Full Version

Symfony 3 Redirect All Routes To Current Locale Version

Short Version

To make it so that case #2 in my examples is possible you need to do so using a httpKernal listner

LocaleRewriteListener.php

router = $router;
        $this->routeCollection = $router->getRouteCollection();
        $this->defaultLocale = $defaultLocale;
        $this->supportedLocales = $supportedLocales;
        $this->localeRouteParam = $localeRouteParam;
    }

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

    public function onKernelRequest(GetResponseEvent $event)
    {
        //GOAL:
        // Redirect all incoming requests to their /locale/route equivlent as long as the route will exists when we do so.
        // Do nothing if it already has /locale/ in the route to prevent redirect loops

        $request = $event->getRequest();
        $path = $request->getPathInfo();

        $route_exists = false; //by default assume route does not exist.

        foreach($this->routeCollection as $routeObject){
            $routePath = $routeObject->getPath();
            if($routePath == "/{_locale}".$path){
                $route_exists = true;
                break;
            }
        }

        //If the route does indeed exist then lets redirect there.
        if($route_exists == true){
            //Get the locale from the users browser.
            $locale = $request->getPreferredLanguage();

            //If no locale from browser or locale not in list of known locales supported then set to defaultLocale set in config.yml
            if($locale==""  || $this->isLocaleSupported($locale)==false){
                $locale = $request->getDefaultLocale();
            }

            $event->setResponse(new RedirectResponse("/".$locale.$path));
        }

        //Otherwise do nothing and continue on~
    }

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

To understand how that is working look up the event subscriber interface on symfony documentation.

To activate the listner you need to set it up in your services.yml

services.yml

# Learn more about services, parameters and containers at
# http://symfony.com/doc/current/book/service_container.html
parameters:
#    parameter_name: value

services:
#    service_name:
#        class: AppBundle\Directory\ClassName
#        arguments: ["@another_service_name", "plain_value", "%parameter_name%"]
     appBundle.eventListeners.localeRewriteListener:
          class: AppBundle\EventListener\LocaleRewriteListener
          arguments: ["@router", "%kernel.default_locale%", "%locale_supported%"]
          tags:
            - { name: kernel.event_subscriber }

Finally this refers to variables that need to be defined in your config.yml

config.yml

# Put parameters here that don't need to change on each machine where the app is deployed
# http://symfony.com/doc/current/best_practices/configuration.html#application-related-configuration
parameters:
    locale: en
    app.locales: en|es|zh
    locale_supported: ['en','es','zh']

Finally, you need to make sure all your routes start with /{locale} for now on. A sample of this is below in my default controller.php

get('translator')->trans('Symfony is great');

        // replace this example code with whatever you need
        return $this->render('default/index.html.twig', [
            'base_dir' => realpath($this->container->getParameter('kernel.root_dir').'/..'),
            'translated' => $translated
        ]);
    }

    /**
     * @Route("/admin", name="admin")
     */
    public function adminAction(Request $request)
    {
        $translated = $this->get('translator')->trans('Symfony is great');

        // replace this example code with whatever you need
        return $this->render('default/index.html.twig', [
            'base_dir' => realpath($this->container->getParameter('kernel.root_dir').'/..'),
            'translated' => $translated
        ]);
    }
}
?>

Note the requirements requirements={"_locale" = "%app.locales%"}, this is referencing the config.yml file so you only have to define those requirements in one place for all routes.

Hope this helps someone :)