Sessions#

Session support in PHP consists of a way to preserve certain data across subsequent accesses such as logged in user information and security tokens.

In order to support things like testing, the session is associated with a particular Controller. In normal usage, this is loaded from and saved to the regular PHP session, but for things like static-page-generation and unit-testing, you can create multiple Controllers, each with their own session.

Getting the session instance#

If you're in a controller, the Session object will be bound to the HTTPRequest for your controller.

namespace App\Control;

use SilverStripe\Control\Controller;

class MyController extends Controller
{
    public function getSession()
    {
        return $this->getRequest()->getSession();
    }
}

Otherwise, if you're not in a controller, get the request as a service.

use SilverStripe\Control\HTTPRequest;
use SilverStripe\Core\Injector\Injector;

$request = Injector::inst()->get(HTTPRequest::class);
$session = $request->getSession();

Set#

$session->set('MyValue', 6);

Saves the value of to session data. You can also save arrays or serialized objects in session (but note there may be size restrictions as to how much you can save).

// saves an array
$session->set('MyArrayOfValues', ['1','2','3']);

// saves an object (you'll have to unserialize it back)
$object = new Object();
$session->set('MyObject', serialize($object));

Get#

Once you have saved a value to the Session you can access it by using the get function. Like the set function you can use this anywhere in your PHP files.

echo $session->get('MyValue');
// returns 6

$data = $session->get('MyArrayOfValues');
// $data = [1,2,3]

$object = unserialize($session->get('MyObject', $object));
// $object = Object()

GetAll#

You can also get all the values in the session at once. This is useful for debugging.

$session->getAll();
// returns an array of all the session values.

Clear#

Once you have accessed a value from the Session it doesn't automatically wipe the value from the Session, you have to specifically remove it.

$session->clear('MyValue');

Or you can clear every single value in the session at once. Note Silverstripe CMS stores some of its own session data including form and page comment information. None of this is vital but clear_all will clear everything.

$session->clearAll();

Cookies#

Samesite attribute#

The session cookie is handled slightly differently than most cookies on the site, which provides the opportunity to handle the samesite attribute separately from other cookies. You can change the samesite attribute for session cookies like so:

SilverStripe\Control\Session:
  cookie_samesite: 'Strict'

Secure session cookie#

In certain circumstances, you may want to use a different session_name cookie when using the https protocol for security purposes. To do this, you may set the cookie_secure parameter to true on your config.yml

SilverStripe\Control\Session:
  cookie_secure: true

This uses the session_name SECSESSID for https connections instead of the default PHPSESSID. Doing so adds an extra layer of security to your session cookie since you no longer share http and https sessions.

Note that if you set cookie_samesite to None (which is strongly discouraged), the cookie_secure value will always be true.

Relaxing checks around user agent strings#

Out of the box, Silverstripe CMS will invalidate a user's session if the User-Agent header changes. This provides some supplemental protection against session high-jacking attacks.

It is possible to disable the user agent header session validation. However, it is not recommended.

To disable the user agent session check, add the following code snippet to your project's YAML configuration.

SilverStripe\Control\Session:
  strict_user_agent_check: false

API documentation#

• Session