Symfony 2 - Load security configuration depending on parameter

AppKernel.php

<?php

use Symfony\Component\Config\Loader\LoaderInterface;
use Symfony\Component\DependencyInjection\ContainerBuilder;
use Symfony\Component\HttpKernel\Kernel;
use Symfony\Component\Yaml\Yaml;

class AppKernel extends Kernel
{
    public function registerBundles()
    {
      // ...
    }

    public function registerContainerConfiguration(LoaderInterface $loader)
    {
        // Load common configuration except security.yml.
        $loader->load($this->getRootDir().'/config/config_'.$this->getEnvironment().'.yml');

        // Security has to be added in one go and can't be overwritten. So it has to be loaded after the common
        // configuration and manipulated before injecting into the loader.
        $loader->load(function (ContainerBuilder $container) {
            // Load security configuration
            $security = Yaml::parse(file_get_contents(
                __DIR__.'/config/security.yml'
            ));

            // Just make life easier
            $security = $security['security'];

            // Setup security configuration depending on the login type
            // The configuration is not parsed yet, but we can access parameters set in parameters.yml.dist
            switch ($container->getParameter('app_login_type')) {
                case 'form_login':
                    unset($security['firewalls']['secured_area']['http_basic']);
                    unset($security['firewalls']['secured_area']['switch_user']);
                    unset($security['firewalls']['secured_area']['remote_user']);
                    break;
                case 'shibboleth':
                    unset($security['firewalls']['login_firewall']);
                    unset($security['firewalls']['register_firewall']);
                    unset($security['firewalls']['secured_area']['anonymous']);
                    unset($security['firewalls']['secured_area']['http_basic']);
                    unset($security['firewalls']['secured_area']['switch_user']);
                    unset($security['firewalls']['secured_area']['form_login']);
                    break;
                case 'dev':
                    // Do nothing, but make sure we can output an exception in case of a wrong parameter value
                    break;
                default:
                    // Inform an invalid parameter value is found
                    throw new Exception('Invalid login type parameter.');
                    break;
            }

            // Inject the security configuration
            $container->loadFromExtension('security', $security);
        });
    }
}