cache:pool:clear command. This command will delete all data from the project storage directory. By default, Symfony comes with 3 cache clearers. They arecache.global_clearercache.system_clearercache.app_clearernamespace FreeTimeLearn\DemoBundle; 
use Symfony\Component\HttpKernel\Bundle\Bundle;  
class FreeTimeLearnDemoBundle extends Bundle { 
}public function registerBundles() { 
   $bundles = array( 
      // ... 
      // register your bundle 
      new FreeTimeLearn\DemoBundle\FreeTimeLearnDemoBundle(), 
   ); 
   return $bundles; 
}php bin/console generate:bundle --namespace = FreeTimeLearn/DemoBundleSensioFrameworkExtraBundle and JMSSecurityExtraBundle which provide better support for annotations. Using these bundles you can use annotations for controller configuration, routing, cache, security, template, etc.                                                                    $session = new Session();  
$session->start();  $session->set('user_id', 200);  $session->get('user_id');  $session->remove('user_id');  $request->get("_route"); //OR with Twig {{ app.request.attributes.get('_route') }};).Directives are used to control Modules and divided into simple directives and block directives.php -r "readfile('https://symfony.com/installer');" > symphony  sudo mkdir -p /usr/local/bin    
sudo curl -LsS https://symfony.com/installer -o /usr/local/bin/symfony    
sudo chmod a+x /usr/local/bin/symfony$request->query->get('paraemeter_name') method is used to get the request parameters in symfony2.                                                                    registerBundles() method is used to enable bundles in Symfony.                                                                    createFromGlobals():use Symfony\Component\HttpFoundation\Request;
$request = Request::createFromGlobals();__construct() call :$request = new Request(
    $_GET,
    $_POST,
    [],
    $_COOKIE,
    $_FILES,
    $_SERVER
);$_POST;$_GET ($request->query->get('name'));$_COOKIE; (see below);$_FILES;$_SERVER;$_SERVER ($request->headers->get('User-Agent')).getPathInfo() method :// for a request to http://example.com/blog/index.php/post/hello-world
// the path info is "/post/hello-world"
$request->getPathInfo();$request = Request::create(
    '/hello-world',
    'GET',
    ['name' => 'Fabien']
);use App\Http\SpecialRequest;
use Symfony\Component\HttpFoundation\Request;
Request::setFactory(function (
    array $query = [],
    array $request = [],
    array $attributes = [],
    array $cookies = [],
    array $files = [],
    array $server = [],
    $content = null
) {
    return new SpecialRequest(
        $query,
        $request,
        $attributes,
        $cookies,
        $files,
        $server,
        $content
    );
});
$request = Request::createFromGlobals();use Symfony\Component\HttpFoundation\Response;
$response = new Response(
    'Content',
    Response::HTTP_OK,
    ['content-type' => 'text/html']
);$response->setContent('Hello World');
// the headers public attribute is a ResponseHeaderBag
$response->headers->set('Content-Type', 'text/plain');
$response->setStatusCode(Response::HTTP_NOT_FOUND);setCharset() method :$response->setCharset('ISO-8859-1');$response->prepare($request);send() :$response->send();public function indexAction()    
    {    
        return $this->render('user/index.html.twig', [ ]);    
    } use Symfony\Component\Form\Extension\Core\Type\EmailType;     
   
$builder->add('token', EmailType::class, array(     
   
'data' => 'abcdef', )); Use Symfony\Component\Validator\Constraints as Assert;
class Student {     
/**   
   * @Assert\Email(   
    * message = "The email '{{ value }}' is not a valid email.",   
     * checkMX = true   
      * )   
*/     
  protected $email;     
}if ($request->isXmlHttpRequest()) {   
   // Ajax request      
} else {      
   // Normal request       
}public function sessionAction(SessionInterface $session)  
{  
    // store an attribute for reuse during a later user request  
    $session->set('user_id', 5);  
   // get the attribute set by another controller in another request  
    $user_id = $session->get('user_id');    
}use Zend\Mvc\Controller\AbstractActionController; 
use Zend\View\Model\ViewModel;      
   
class IndexController extends AbstractActionController {
   public function indexAction() {     
      return new ViewModel();     
   }     
}safe" mode to assist those who don't want to be exposed to content to which they might object. The RFC 8674 specification defines a way for user agents to ask for safe content to a server.preferSafeContent();setContentSafe();if ($request->preferSafeContent()) {
    $response = new Response($alternativeContent);
    // this informs the user we respected their preferences
    $response->setContentSafe();
    return $response;