PHP/Class/ wakeup

Using __sleep() and __wakeup() for Objects

 
<?php
     class UserClass {
          public $sessionID;
          public $username;
          public function __sleep() {
               session_destroy();
               return array("username");
          }
          public function __wakeup() {
               session_start();
               $this->sessionId = session_id();
          }
     }
     session_start();
     $user = new UserClass;
     $user->sessionId = session_id();
     $seralized_user = serialize($user);
     unset($user);
     $user = unserialize($serialized_user);
?>

__wakeup() is called by unserialize().

 
<?
class apple {
  var $frozen = 0;
  function ___sleep( ) {
    $this->frozen++;
    return array_keys( get_object_vars( $this) );
  }
  function __wakeup( ) {
      print $this->frozen." time(s)";
  }
}
$app = new apple ( );
$stored = serialize( $app );
print $stored;
$new_app = unserialize( $stored );
?>