symfony - 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:

example: 
    pattern:  /{_locale}/example 
    defaults: { _controller: ExampleBundle:Example:index, _locale: fr } 

It works fine with URLs like:

mysite.com/en/example 
mysite.com/fr/example 

But doesn't work with

mysite.com/example 

Could it be that optional placeholders are permitted only at the end of an URL ?
If yes, what could be a possible solution for displaying an url like :

mysite.com/example  

in a default language or redirecting the user to :

mysite.com/defaultlanguage/example 

when he visits :

mysite.com/example. ? 

I'm trying to figure it out but without success so far.

Thanks.

Answer 1

If someone is interested in, I succeeded to put a prefix on my routing.yml without using other bundles.

So now, thoses URLs work :

www.example.com/
www.example.com//home/
www.example.com/fr/home/
www.example.com/en/home/

Edit your app/config/routing.yml:

ex_example:
    resource: "@ExExampleBundle/Resources/config/routing.yml"
    prefix:   /{_locale}
    requirements:
        _locale: |fr|en # put a pipe "|" first

Then, in you app/config/parameters.yml, you have to set up a locale

parameters:
    locale: en

With this, people can access to your website without enter a specific locale.