ChainedDependency.php 2.91 KB
Newer Older
Qiang Xue committed
1 2 3
<?php
/**
 * @link http://www.yiiframework.com/
Qiang Xue committed
4
 * @copyright Copyright (c) 2008 Yii Software LLC
Qiang Xue committed
5 6 7
 * @license http://www.yiiframework.com/license/
 */

Qiang Xue committed
8 9
namespace yii\caching;

Qiang Xue committed
10
/**
Qiang Xue committed
11
 * ChainedDependency represents a dependency which is composed of a list of other dependencies.
Qiang Xue committed
12
 *
Qiang Xue committed
13 14 15
 * When [[dependOnAll]] is true, if any of the dependencies has changed, this dependency is
 * considered changed; When [[dependOnAll]] is false, if one of the dependencies has NOT changed,
 * this dependency is considered NOT changed.
Qiang Xue committed
16 17 18 19
 *
 * @property boolean $hasChanged Whether the dependency is changed or not.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
Qiang Xue committed
20
 * @since 2.0
Qiang Xue committed
21
 */
Qiang Xue committed
22
class ChainedDependency extends Dependency
Qiang Xue committed
23 24
{
	/**
25 26
	 * @var Dependency[] list of dependencies that this dependency is composed of.
	 * Each array element must be a dependency object.
Qiang Xue committed
27
	 */
28
	public $dependencies;
Qiang Xue committed
29 30 31 32 33 34 35
	/**
	 * @var boolean whether this dependency is depending on every dependency in [[dependencies]].
	 * Defaults to true, meaning if any of the dependencies has changed, this dependency is considered changed.
	 * When it is set false, it means if one of the dependencies has NOT changed, this dependency
	 * is considered NOT changed.
	 */
	public $dependOnAll = true;
Qiang Xue committed
36 37

	/**
Qiang Xue committed
38
	 * Constructor.
39 40
	 * @param Dependency[] $dependencies list of dependencies that this dependency is composed of.
	 * Each array element should be a dependency object.
Qiang Xue committed
41
	 * @param array $config name-value pairs that will be used to initialize the object properties
Qiang Xue committed
42
	 */
Qiang Xue committed
43
	public function __construct($dependencies = array(), $config = array())
Qiang Xue committed
44
	{
Qiang Xue committed
45
		$this->dependencies = $dependencies;
Qiang Xue committed
46
		parent::__construct($config);
Qiang Xue committed
47 48 49
	}

	/**
Qiang Xue committed
50
	 * Evaluates the dependency by generating and saving the data related with dependency.
51
	 * @param Cache $cache the cache component that is currently evaluating this dependency
Qiang Xue committed
52
	 */
53
	public function evaluateDependency($cache)
Qiang Xue committed
54
	{
Qiang Xue committed
55
		foreach ($this->dependencies as $dependency) {
56
			$dependency->evaluateDependency($cache);
Qiang Xue committed
57 58 59 60
		}
	}

	/**
Qiang Xue committed
61 62
	 * Generates the data needed to determine if dependency has been changed.
	 * This method does nothing in this class.
63
	 * @param Cache $cache the cache component that is currently evaluating this dependency
Qiang Xue committed
64
	 * @return mixed the data needed to determine if dependency has been changed.
Qiang Xue committed
65
	 */
66
	protected function generateDependencyData($cache)
Qiang Xue committed
67
	{
Qiang Xue committed
68
		return null;
Qiang Xue committed
69 70 71 72 73 74
	}

	/**
	 * Performs the actual dependency checking.
	 * This method returns true if any of the dependency objects
	 * reports a dependency change.
75
	 * @param Cache $cache the cache component that is currently evaluating this dependency
Qiang Xue committed
76 77
	 * @return boolean whether the dependency is changed or not.
	 */
78
	public function getHasChanged($cache)
Qiang Xue committed
79
	{
80
		foreach ($this->dependencies as $dependency) {
81
			if ($this->dependOnAll && $dependency->getHasChanged($cache)) {
Qiang Xue committed
82
				return true;
83
			} elseif (!$this->dependOnAll && !$dependency->getHasChanged($cache)) {
Qiang Xue committed
84 85
				return false;
			}
Qiang Xue committed
86
		}
Qiang Xue committed
87
		return !$this->dependOnAll;
Qiang Xue committed
88 89
	}
}