使用 session 存储数据（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

启动会话（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:

<?php

use Phalcon\Session\Adapter\Files as Session;

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

会话数据的存储与读取（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:

<?php

use Phalcon\Mvc\Controller;

class UserController extends 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");
        }
    }

}

会话数据的删除和销毁（Removing/Destroying Sessions）¶

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

<?php

use Phalcon\Mvc\Controller;

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

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

隔离不同应用的会话数据（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:

<?php

use Phalcon\Session\Adapter\Files as Session;

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

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

    $session->start();

    return $session;
});

Adding a unique ID is not necessary.

会话袋（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:

<?php

use Phalcon\Session\Bag as SessionBag;

$user       = new SessionBag('user');
$user->setDI($di);
$user->name = "Kimbra Johnson";
$user->age  = 22;

组件的持久数据（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.

<?php

use Phalcon\Mvc\Controller;

class UserController extends 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:

<?php

use Phalcon\Mvc\Controller;

class Security extends 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.

会话适配器（Session Adapters）¶

这些适配器封装特定的数据存储方式的详细操作，下面是我们支持的数据存储方式：

名称	描述	API
Files	将会话数据存储在文本文件	Phalcon\Session\Adapter\Files
memcached	利用 Memcached 扩展，将会话数据存储在 Memcached	Phalcon\Session\Adapter\Memcached
Memcached	使用缓存组件，将会话数据存储在缓存组件对应的存储服务器中	Phalcon\Session\Adapter\Memcached

自定义适配器（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.

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