# 使用 Session 存儲數據（Storing data in Session） 會話組件組件提供了一種面向對象的方式訪問session數據。 使用這個組件替代原生session的原因如下: * 在相同域名下的不同應用程序之間，你可以非常容易的隔離session數據 * Intercept where session data is set/get in your application * 根據應用程序的需要，可以非常方便的更換session適配器 ## 啟動會話（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; } ); ~~~ ## Session 的存儲與讀取（Storing/Retrieving data in Session） 控制器，視圖或者任何繼承于[Phalcon\\Di\\Injectable](http://docs.iphalcon.cn/api/Phalcon_Di_Injectable.html)的組件，都可以訪問session服務。 如下示例介紹了session的存儲與讀取操作: ~~~ <?php use Phalcon\Mvc\Controller; class UserController extends Controller { public function indexAction() { // 設置一個session變量 $this->session->set("user-name", "Michael"); } public function welcomeAction() { // 檢查session變量是否已定義 if ($this->session->has("user-name")) { // 獲取session變量的值 $name = $this->session->get("user-name"); } } } ~~~ ## Sessions 的刪除和銷毀（Removing/Destroying Sessions） 你也可以刪除某個session變量，或者銷毀全部session會話: ~~~ <?php use Phalcon\Mvc\Controller; class UserController extends Controller { public function removeAction() { // 刪除session變量 $this->session->remove("user-name"); } public function logoutAction() { // 銷毀全部session會話 $this->session->destroy(); } } ~~~ ## 隔離不同應用的會話數據（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( [ "uniqueId" => "my-app-1", ] ); $session->start(); return $session; } ); ~~~ Adding a unique ID is not necessary. ## 會話袋（Session Bags） [Phalcon\\Session\\Bag](http://docs.iphalcon.cn/api/Phalcon_Session_Bag.html)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; ~~~ ## 組件的持久數據（Persistent Data in Components） Controller, components and classes that extends[Phalcon\\Di\\Injectable](http://docs.iphalcon.cn/api/Phalcon_Di_Injectable.html)may inject a[Phalcon\\Session\\Bag](http://docs.iphalcon.cn/api/Phalcon_Session_Bag.html). 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. ## 自定義適配器（Implementing your own adapters） The[Phalcon\\Session\\AdapterInterface](http://docs.iphalcon.cn/api/Phalcon_Session_AdapterInterface.html)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](https://github.com/phalcon/incubator/tree/master/Library/Phalcon/Session/Adapter)