Storing data in Session

The Phalcon\Session provides object-oriented wrappers to access session data.

Reasons to use this component instead of raw-sessions:

• You can easily isolate session data across applications on the same domain
• Intercept where session data is set/get in your application
• Change the session adapter according to the application needs

Starting the Session

Some applications are session-intensive, almost any action that performs requires access to session data. There are others who access session data casually. Thanks to the service container, we can ensure that the session is accessed only when it’s clearly needed:

//Start the session the first time when some component request the session service
$di->setShared('session', function() {
    $session = new Phalcon\Session\Adapter\Files();
    $session->start();
    return $session;
});

Storing/Retrieving data in Session

From a controller, a view or any other component that extends Phalcon\DI\Injectable you can access the session service and store items and retrieve them in the following way:

class UserController extends Phalcon\Mvc\Controller
{

    public function indexAction()
    {
        //Set a session variable
        $this->session->set("user-name", "Michael");
    }

    public function welcomeAction()
    {

        //Check if the variable is defined
        if ($this->session->has("user-name")) {

            //Retrieve its value
            $name = $this->session->get("user-name");
        }
    }

}

Removing/Destroying Sessions

It’s also possible remove specific variables or destroy the whole session:

class UserController extends Phalcon\Mvc\Controller
{

    public function removeAction()
    {
        //Remove a session variable
        $this->session->remove("user-name");
    }

    public function logoutAction()
    {
        //Destroy the whole session
        $this->session->destroy();
    }

}

Isolating Session Data between Applications

Sometimes a user can use the same application twice, on the same server, in the same session. Surely, if we use variables in session, we want that every application have separate session data (even though the same code and same variable names). To solve this, you can add a prefix for every session variable created in a certain application:

//Isolating the session data
$di->set('session', function(){

    //All variables created will prefixed with "my-app-1"
    $session = new Phalcon\Session\Adapter\Files(
        array(
            'uniqueId' => 'my-app-1'
        )
    );

    $session->start();

    return $session;
});

Session Bags

Phalcon\Session\Bag is a component that helps separating session data into “namespaces”. Working by this way you can easily create groups of session variables into the application. By only setting the variables in the “bag”, it’s automatically stored in session:

$user       = new Phalcon\Session\Bag('user');
$user->setDI($di);
$user->name = "Kimbra Johnson";
$user->age  = 22;

Persistent Data in Components

Controller, components and classes that extends Phalcon\DI\Injectable may inject a Phalcon\Session\Bag. This class isolates variables for every class. Thanks to this you can persist data between requests in every class in an independent way.

class UserController extends Phalcon\Mvc\Controller
{

    public function indexAction()
    {
        // Create a persistent variable "name"
        $this->persistent->name = "Laura";
    }

    public function welcomeAction()
    {
        if (isset($this->persistent->name))
        {
            echo "Welcome, ", $this->persistent->name;
        }
    }

}

In a component:

class Security extends Phalcon\Mvc\User\Component
{

    public function auth()
    {
        // Create a persistent variable "name"
        $this->persistent->name = "Laura";
    }

    public function getAuthName()
    {
        return $this->persistent->name;
    }

}

The data added to the session ($this->session) are available throughout the application, while persistent ($this->persistent) can only be accessed in the scope of the current class.

Implementing your own adapters

The Phalcon\Session\AdapterInterface interface must be implemented in order to create your own session adapters or extend the existing ones.

There are more adapters available for this components in the Phalcon Incubator