PHP一个类AOP的实现

<?php

/**
 * 包装器(Wrapper).
 * Wrapper是一个AOP_LIKE的实现. 也可以看作监听者模式的实现.
 * 一个Wrapper报装了一个对象(source). source可以是任意对象(不包括数组及原子类型),甚至是一个Wrapper.
 *
 * 包装器可以任意添加饰品(Decoration).通过Wrapper调用source的函数的流程将是:
 *	unpacking --> teardown --> open --> setup --> packing.
 *
 *	例如调用source->doXX(),各个流程将是:
 *	unpacking: 	解包. 这是调用任意source的函数都会调用的方法;
 *	teardown: 	撕掉饰品. 对于Wrapper中的每个Decoration,调用其before()函数;
 *	open: 		真正调用source->doXX()函数;
 *	setup: 		重新贴上饰品. 对于Wrapper中的每个Decoration,调用其after()函数;
 *	packing:	重新打包.  这是调用任意source的函数都会调用的方法;
 *
 */
class Wrapper{
	private $source;

	/**
	 * @var bool
	 */
	private $undecorated;

	/**
	 * @var array[Decoration]
	 */
	private $decorations=array();

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

	public function __call($name,$parameters){
		$this->unpacking($name,$parameters);
		$this->tearDown($name,$parameters);

		// opening
		if(method_exists($this->source, $name)){
			$retval = call_user_func_array(array($this->source,$name),$parameters);
		}

		$this->setup($retval,$name,$parameters);
		$this->packing($retval,$name,$parameters);

		return $retval;
	}

	public function unpacking($name,$parameters){
	}

	public function packing($name,$parameters){
	}

	public function tearDown($name,$parameters){
		if($this->undecorated){
			return;
		}
		foreach ($this->decorations as $d){
			$d->before($name,$parameters);
		}
	}

	public function setup($retval,$name,$parameters){
		if($this->undecorated){
			return ;
		}
		foreach ($this->decorations as $d){
			$d->after($retval,$name,$parameters);
		}
	}

	public function decarate($decoration){
		$this->decorations[] = $decoration;
	}



	public static function wrap($source){
		//  wrap the source
		$wrapperConfig = app()->wrappers[get_class($source)];
		if($wrapperConfig){
			$wrapperClass = $wrapperConfig['class'];
			$wrapper = new $wrapperClass($source);

			foreach ($wrapperConfig['decorations'] as $item){
				$decoration = new $item;
				$wrapper->decarate($decoration);
			}
		}
		return $wrapper?$wrapper:$source;
	}

}

?>

	'wrappers'=>array(
			'ContentService'=>array(
					'class'=>'ContentWrapper',
					'decorations'=>array(
							'DasaiContentDecoration',
					)
			),
			'AOPWorker'=>array(//for test
				'class'=>'DiagnosisWrapper',
				'decorations'=>array(
					'DasaiDiagnosisDecoration'
				),
			),
	),

class AOPWorker{
	public function testAOP(){
		Debugger::print_r(
			"\n工人:我要做一大堆操作了
				\n工人:... ...
				\n工人:好了 做完了\n");
		return 'OK';
	}

}


public function testAOP(){// test aop  测试入口
		$aop = Wrapper::wrap(new AOPWorker());
		$aop->testAOP(33347);
}



class DiagnosisWrapper extends Wrapper{

	public function unpacking($name, $parameters){
		echo "\nDiagnosisWrapper:喂,有人调用$name,我要解包了.\n";
	}


	public function packing($retval,$name, $parameters){
		echo "\nDiagnosisWrapper:喂,调用$name,结果为$retval,重新打包好了.\n";
	}
}



class DasaiDiagnosisDecoration extends Decoration {
	public function before($name,$parameters){
		echo "\r\nDasaiDiagnosisDecoration:开始调用$name,已经告诉张三李四了.\n";
	}

	public function after($retval,$name,$parameters){
		echo "\nDasaiDiagnosisDecoration:结束调用$name,告诉霍金和Sheldon了.\n";
	}
}