php框架中常用的设计模式

1.单例模式

 //单例模式
 class Demo
 {
     private static $obj;

     private function __construct()
     {

     }

     private function __clone()
     {

     }

     public static function OBJ()
     {
         if(!isset(self::$obj))
         {
             self::$obj = new self;
         }
         return self::$obj;
     }

 }

2.工厂模式

//简单工厂模式
//抽象方法
abstract  class  operation
{
    abstract public function getValue($one,$two);
}

//jia  fa  lei
class operationAdd extends operation
{
    public function getValue($one, $two)
    {
        return $one + $two;
    }
}

class operationSub extends operation
{
    public function getValue($one, $two)
    {
        return $one - $two;
    }
}

class factory
{
    public static function getObject($name)
    {
        switch($name){
        case '+': return new operationAdd(); break;
        case '-': return new operationSub(); break;
        default:
            break;    

        }
    }

}

$demo = factory::getObject('+');
$value = $demo->getValue(2,1);
echo $value;

3.注册器模式（把每次new的对象放到一个静态数组中）

4. 观察者模式

把每个需要通知的类，实例化后的对象交给观察者类中的静态数组保存，然后调用观察者类的方法，方法的作用是便利静态数组，调用每个对象中的通知方法

　

 <?php
 //guan cha zhe lei
 class Server
 {
     private static $objList = array();

     public function add($obj)
     {
         self::$objList[] = $obj;
     }

     public function notify()
     {
         foreach(self::$objList as $obj)
         {
             $obj->notify();
         }
     }
 }

 abstract class client
 {
     abstract public function notify();
 }

 class one extends client
 {
     public function notify()
     {
         echo "one<br>";
     }
 }

 class two extends client
 {
     public function notify()
     {
         echo "two<br>";
     }
 }

 $server = new Server(); 

 $one = new one();
 $two = new two();

 $server->add($one);
 $server->add($two);

 $server->notify();