Laravel 5 Route filter regex

Question

I'm trying to implement a laravel website that supports two languages (pt and en with pt fallback already implemented). The desired url's should be www.example.com/pt/list for portuguese and www.example.com/en/list for english. When no language is inserted, should work with pt for default. I have the following code: [routes.php]

Route::filter('localization', function() {
    App::setLocale(Route::input('lang'));
});
Route::group(['prefix' => '{lang?}', 'before' => 'localization'], function() {
    Route::get('/', 'HomeController@index');
    Route::get('/list','ListController@index');
});

When language is defined all works well, but otherwise it will always redirect to the homepage even when there is no router to this URL. How can I avoid this behaviour? Is it possible to do a regex on a group? Guess the Jason Lewis' Enhanced Router only works in Laravel 4

EDIT 1: I could fix it using redirects in htaccess (if no language prefix, then redirect using /pt/ prefix but there must be another way I guess)

EDIT 2: Can fix it using the following piece of code but it also involves using redirects, which I guess it could be prevented and the url will always have the language parameter

Route::filter('localization', function() {
    $accepted_language = array("pt","en");

    $first_segment = Route::input("lang");
    if(in_array($first_segment,$accepted_language))
    {
        /*ALL GOOD, Language in URL*/
        App::setLocale(Route::input('lang'));
    }
    else
    {
        /*REDIRECT WITH LANGUAGE*/
        $segments   = Request::segments();
        $imploded   = implode("/",$segments);
        $url        = "/pt/".$imploded;
        return Redirect::to($url, 301);
    }

});

Answer 1

In my recent project I had the same problem. You can do it like this:

$languages = array('en', 'pt');
$locale = Request::segment(1);

if (in_array($locale, $languages))
{
    App::setLocale($locale);
}
else
{
    redirect('pt')->send();
}

Route::group(['prefix' => $locale], function()
{
    Route::get('/', 'HomeController@index');
    Route::get('list','ListController@index');
});

Or move locales check into the separate middleware.