www.gusucode.com > 24Beta 虚拟主机版 1.0.0 Beta源码程序 > 24Beta 虚拟主机版 1.0.0 Beta源码程序/24Beta-1.0.0-vhost/library/framework/caching/dependencies/CExpressionDependency.php
<?php /** * CExpressionDependency class file. * * @author Qiang Xue <qiang.xue@gmail.com> * @link http://www.yiiframework.com/ * @copyright Copyright © 2008-2009 Yii Software LLC * @license http://www.yiiframework.com/license/ */ /** * CExpressionDependency represents a dependency based on the result of a PHP expression. * * CExpressionDependency performs dependency checking based on the * result of a PHP {@link expression}. * The dependency is reported as unchanged if and only if the result is * the same as the one evaluated when storing the data to cache. * * @author Qiang Xue <qiang.xue@gmail.com> * @version $Id: CExpressionDependency.php 883 2009-03-23 20:52:35Z qiang.xue $ * @package system.caching.dependencies * @since 1.0 */ class CExpressionDependency extends CCacheDependency { /** * @var string the PHP expression whose result is used to determine the dependency. */ public $expression; /** * Constructor. * @param string the PHP expression whose result is used to determine the dependency. */ public function __construct($expression='true') { $this->expression=$expression; } /** * Generates the data needed to determine if dependency has been changed. * This method returns the result of the PHP expression. * @return mixed the data needed to determine if dependency has been changed. */ protected function generateDependentData() { return @eval('return '.$this->expression.';'); } }