Symfony - Cookies and Session Management

Symfony HttpFoundation component provides cookie and session management in an object-oriented manner. Cookie provides cpent-side data storage and it only supports a small amount of data. Usually, it is 2KB per domain and it depends on the browser. Session provides server-side data storage and it supports a large amount of data. Let us see how to create a cookie and session in a Symfony web apppcation.

Cookie

Symfony provides Cookie class to create a cookie item. Let us create a cookie color, which expires in 24 hours with value blue. The constructor parameter of the cookie class is as follows.

name (type: string) - cookie name

value (type: string) - cookie value

expire (type: integer / string / datetime) - expiry information

path (type: string) - the server path in which the cookie is available

domain (type: string) – the domain address in which the cookie is available

secure (type: boolean) - whether the cookie needs to be transmitted in HTTPS connection

httpOnly (type: boolean) - whether the cookie is available only in HTTP protocol

use SymfonyComponentHttpFoundationCookie;  
$cookie = new Cookie( color ,  green , strtotime( tomorrow ),  / , 
    somedomain.com , true, true);

Symfony also provides the following string-based cookie creation option.

$cookie = Cookie::fromString( color = green; expires = Web, 4-May-2017 18:00:00 +0100; 
path=/; domain = somedomain.com; secure; httponly );

Now, the created cookie needs to be attached to the http response object s header as follows.

$response->headers->setCookie($cookie);

To get the cookie, we can use Request object as follows.

$cookie = $request->cookie->get( color ); 

Here, request->cookie is of type PropertyBag and we can manipulate it using PropertyBag methods.

Session

Symfony provides a Session class implementing SessionInterface interface. The important session API are as follows,

start − Starts the session.

Session $session = new Session(); 
$session->start(); 

invapdate − Clears all session data and regenerates the session ID.

set − Stores data in the session using a key.

$session->set( key ,  value );

We can use any data in the session value, be in simple integer to complex objects.

get − Gets data from the session using the key.

$val = $session->get( key );

remove − Removes a key from the session.

clear − Removes a session data.

FlashBag

Session provides another useful feature called FlashBag. It is a special container inside the session holding the data only during page redirection. It is useful in http redirects. Before redirecting to a page, data can be saved in FlashBag instead of a normal session container and the saved data will be available in the next request (the redirected page). Then, the data will be invapdated automatically.

$session->getFlashBag()->add( key ,  value );  
$session->getFlashBag()->get( key );