Managing Laravel 4 Localization (Language)

Here is a quick tutorial on how to set and manage session localization in Laravel 4.

The Laravel documentation explains that you create a directory in app/lang representing each language you wish to support. For example, for the English language you may have app/lang/en directory and for the Spanish language you may have app/lang/es. 

I use controllers because I like how it organizes my code. Therefore, this article will be using controllers.

First, I set the applications default locale (i.e. language) and add a list of supported locales to the app/config/app.php file.
NOTE: the locales parameter is not in the default Laravel distribution. You will need to add this parameter.

....
      /*
      |--------------------------------------------------------------------------
      | Application Locale Configuration
      |--------------------------------------------------------------------------
      |
      | The application locale determines the default locale that will be used
      | by the translation service provider. You are free to set this value
      | to any of the locales which will be supported by the application.
      |
     */
    'locale' => 'en',
    /*

      |--------------------------------------------------------------------------
      | Application Supported Locales
      |--------------------------------------------------------------------------
      |
      | Locales supported by this application.
      |
     */
    'locales' => array(
        'en', // English
        'es', // Spanish
    ),
....

Next, I use the app/controller/BaseController.php for my locale logic because this controller is usually extended from my other controllers.

class BaseController extends Controller
{
    public function __construct()
    {
        $this -> configureLocale();
    }

    /**
     * Action used to set the application locale.
     * 
     */
    public function setLocale()
    {
        $mLocale = Request::segment( 2, Config::get( 'app.locale' ) ); // Get parameter from URL.
        if ( in_array( $mLocale , Config::get( 'app.locales' ) ) )
        {
           App::setLocale( $mLocale );
           Session::put( 'locale', $mLocale );
           Cookie::forever( 'locale', $mLocale );
        }
        return Redirect::back();
    }

    /**
     * Detect and set application localization environment (language).
     * NOTE: Don't foreget to ADD/SET/UPDATE the locales array in app/config/app.php!
     *
     */
    private function configureLocale()
    {
        // Set default locale.
        $mLocale = Config::get( 'app.locale' );

        // Has a session locale already been set?
        if ( !Session::has( 'locale' ) )
        {
            // No, a session locale hasn't been set.
            // Was there a cookie set from a previous visit?
            $mFromCookie = Cookie::get( 'locale', null );
            if ( $mFromCookie != null && in_array( $mFromCookie, Config::get( 'app.locales' ) ) )
            {
                // Cookie was previously set and it's a supported locale.
                $mLocale = $mFromCookie;
            }
            else
            {
                // No cookie was set.
                // Attempt to get local from current URI.
                $mFromURI = Request::segment( 1 );
                if ( $mFromURI != null && in_array( $mFromURI, Config::get( 'app.locales' ) ) )
                {
                    // supported locale
                    $mLocale = $mFromURI;
                }
                else
                {
                    // attempt to detect locale from browser.
                    $mFromBrowser = substr( Request::server( 'http_accept_language' ), 0, 2 );
                    if ( $mFromBrowser != null && in_array( $mFromBrowser, Config::get( 'app.locales' ) ) )
                    {
                        // browser lang is supported, use it.
                        $mLocale = $mFromBrowser;
                    } // $mFromBrowser
                } // $mFromURI
            } // $mFromCookie

            Session::put( 'locale', $mLocale );
            Cookie::forever( 'locale', $mLocale );
        } // Session?
        else
        {
            // session locale is available, use it.
            $mLocale = Session::get( 'locale' );
        } // Session?

        // set application locale for current session.
        App::setLocale( $mLocale );

    }
}

Now that my controller is configured to detected and set the application's locale, I now need to provide an action for the user to change their locale. I typically do it via a menu option like so.

app/view/plugin/navbar.blade.php
NOTE: I'm using twitter bootstrap for my navbar.

....
  <li class="dropdown">
   <a href="#" class="dropdown-toggle" data-toggle="dropdown">{{ Lang::get( 'navbar.locale.label' ) }} <b class="caret"></b></a>
    <ul class="dropdown-menu">
     @foreach( Lang::get( 'navbar.locale.option' ) as $mKey => $mLanguage )
      <li>{{ HTML::linkAction( 'BaseController@setLocale', $mLanguage, $mKey ) }}</li>
     @endforeach
    </ul>
   </li>
....

Next, we need to make sure our app/routes.php can handle the routing

....
Route::get( '/locale/{locale}', 'BaseController@setLocale' );
....

And finally, we need to update composer

$ composer dump-autoload

You can test it directly my entering into your browser the URL to your site like this:

http://mysite/locale/en
or
http://mysite/locale/es