<?php /** * TSessionPageStatePersister class file * * @author Qiang Xue <qiang.xue@gmail.com> * @link http://www.pradosoft.com/ * @copyright Copyright © 2005 PradoSoft * @license http://www.pradosoft.com/license/ * @version $Id$ * @package System.Web.UI */ /** * TSessionPageStatePersister class * * TSessionPageStatePersister implements a page state persistent method based on * sessions. Page state are stored in user sessions and therefore, this persister * requires session to be started and available. * * TSessionPageStatePersister keeps limited number of history states in session, * mainly to preserve the precious server storage. The number is specified * by {@link setHistorySize HistorySize}, which defaults to 10. * * There are a couple of ways to use TSessionPageStatePersister. * One can override the page's {@link TPage::getStatePersister()} method and * create a TSessionPageStatePersister instance there. * Or one can configure the pages to use TSessionPageStatePersister in page configurations * as follows, * <code> * <pages StatePersisterClass="System.Web.UI.TSessionPageStatePersister" /> * </code> * The above configuration will affect the pages under the directory containing * this configuration and all its subdirectories. * To configure individual pages to use TSessionPageStatePersister, use * <code> * <pages> * <page id="PageID" StatePersisterClass="System.Web.UI.TSessionPageStatePersister" /> * </pages> * </code> * * @author Qiang Xue <qiang.xue@gmail.com> * @version $Id$ * @package System.Web.UI * @since 3.1 */ class TSessionPageStatePersister extends TComponent implements IPageStatePersister { const STATE_SESSION_KEY='PRADO_SESSION_PAGESTATE'; const QUEUE_SESSION_KEY='PRADO_SESSION_STATEQUEUE'; private $_page; private $_historySize=10; /** * @param TPage the page that this persister works for */ public function getPage() { return $this->_page; } /** * @param TPage the page that this persister works for. */ public function setPage(TPage $page) { $this->_page=$page; } /** * @return integer maximum number of page states that should be kept in session. Defaults to 10. */ public function getHistorySize() { return $this->_historySize; } /** * @param integer maximum number of page states that should be kept in session * @throws TInvalidDataValueException if the number is smaller than 1. */ public function setHistorySize($value) { if(($value=TPropertyValue::ensureInteger($value))>0) $this->_historySize=$value; else throw new TInvalidDataValueException('sessionpagestatepersister_historysize_invalid'); } /** * Saves state in hidden fields. * @param mixed state to be stored */ public function save($state) { $session=$this->_page->getSession(); $session->open(); $data=serialize($state); $timestamp=(string)microtime(true); $key=self::STATE_SESSION_KEY.$timestamp; $session->add($key,$data); if(($queue=$session->itemAt(self::QUEUE_SESSION_KEY))===null) $queue=array(); $queue[]=$key; if(count($queue)>$this->getHistorySize()) { $expiredKey=array_shift($queue); $session->remove($expiredKey); } $session->add(self::QUEUE_SESSION_KEY,$queue); $this->_page->setClientState(TPageStateFormatter::serialize($this->_page,$timestamp)); } /** * Loads page state from hidden fields. * @return mixed the restored state * @throws THttpException if page state is corrupted */ public function load() { if(($timestamp=TPageStateFormatter::unserialize($this->_page,$this->_page->getRequestClientState()))!==null) { $session=$this->_page->getSession(); $session->open(); $key=self::STATE_SESSION_KEY.$timestamp; if(($data=$session->itemAt($key))!==null) return unserialize($data); } throw new THttpException(400,'sessionpagestatepersister_pagestate_corrupted'); } } ?>