PHP设计模式实例之（观察者模式、策略模式、简单工厂模式）

/**
* 定义观察接口
*/
interface Subject
{
public function Attach($Observer); //添加观察者
public function Detach($Observer); //踢出观察者
public function Notify(); //满足条件时通知观察者
public function SubjectState($Subject); //观察条件
}

/**
* 观察类的具体实现
*/
class Boss Implements Subject
{
public $_action;

private $_Observer;

public function Attach($Observer)
{
$this->_Observer[] = $Observer;
}

public function Detach($Observer)
{
$ObserverKey = array_search($Observer, $this->_Observer);

if($ObserverKey !== false)
{
unset($this->_Observer[$ObserverKey]);
}
}

public function Notify()
{
foreach($this->_Observer as $value )
{
$value->Update();
}
}

public function SubjectState($Subject)
{
$this->_action = $Subject;
}
}

/**
* 抽象观察者
*
*/
abstract class Observer
{
protected $_UserName;

protected $_Sub;

public function __construct($Name,$Sub)
{
$this->_UserName = $Name;
$this->_Sub = $Sub;
}

public abstract function Update(); //接收通过方法
}

/**
* 观察者
*/
class StockObserver extends Observer
{
public function __construct($name,$sub)
{
parent::__construct($name,$sub);
}

public function Update()
{
echo $this->_Sub->_action.$this->_UserName." 你赶快跑...";
}
}

$huhansan = new Boss(); //被观察者

$gongshil = new StockObserver("三毛",$huhansan); //初始化观察者

$huhansan->Attach($gongshil); //添加一个观察者
$huhansan->Attach($gongshil); //添加一个相同的观察者
$huhansan->Detach($gongshil); //踢出基中一个观察者

$huhansan->SubjectState("警察来了"); //达到满足的条件

$huhansan->Notify(); //通过所有有效的观察者

/**
* 定义支持算法的接口
* 省略模式
*/
abstract class Strategy
{
abstract public function AlgorithmInterface();
}

class ConcreateStratA extends Strategy
{
public function AlgorithmInterface()
{
echo "算法A";
}
}

class ConcreateStratB extends Strategy
{
public function AlgorithmInterface()
{
echo "算法B";
}
}

class ConcreateStratC extends Strategy
{
public function AlgorithmInterface()
{
echo "算法C";
}
}

class Context
{
private $_StrObj;

public function __construct($strobj)
{
$this->_StrObj = $strobj;
}

public function ContextInterface()
{
$this->_StrObj->AlgorithmInterface();
}
}

$context = new Context(new ConcreateStratA);
$context->ContextInterface();
$context = new Context(new ConcreateStratC);
$context->ContextInterface();
$context = new Context(new ConcreateStratB);
$context->ContextInterface();

/**
* 定义运算类
* 简单工厂模式
*/
abstract class Operation
{
//存储第一个数字
protected $_NumberA = 0;

//存储第二个数字
protected $_NumberB = 0;

//存储运算结果
protected $_Result = 0;

public function __construct()
{
//empty
}

/**
* 设定需要运行的二个数字
*
* @param 第一个数字 $A
* @param 第二个数字 $B
*/
public function SetNumber($A=0,$B=0)
{
$this->_NumberA = $A;
$this->_NumberB = $B;
}

/**
* 清除所有数据
*
*/
protected function ClearResult()
{
$this->_Result = 0;
}

abstract function GetResult();
}

/**
* 数据相加
*/
class OperactionAdd extends Operation
{
public function GetResult()
{
$this->_Result = $this->_NumberA + $this->_NumberB;

return $this->_Result;
}
}

/**
* 数据相减
*/
class OperactionSub extends Operation
{
public function GetResult()
{
$this->_Result = $this->_NumberA - $this->_NumberB;

return $this->_Result;
}
}

/**
* 数据相乘
*/
class OperactionMul extends Operation
{
public function GetResult()
{
$this->_Result = $this->_NumberA * $this->_NumberB;

return $this->_Result;
}
}

/**
* 数据相除
*/
class OperactionDiv extends Operation
{
public function GetResult()
{
$this->_Result = $this->_NumberA / $this->_NumberB;

return $this->_Result;
}
}

class OperactionFactory
{
private static $_Obj;

public static function CreateOperaction($type)
{
switch($type)
{
case "+":
self::$_Obj = new OperactionAdd;
break;
case "-":
self::$_Obj = new OperactionSub;
break;
case "*":
self::$_Obj = new OperactionMul;
break;
case "/":
self::$_Obj = new OperactionDiv;
break;
}

return self::$_Obj;
}
}

$Obj = OperactionFactory::CreateOperaction("*");
$Obj->SetNumber(6,4);
$num = $Obj->GetResult();
var_dump($num);