仿AS3实现PHP 事件机制实现代码

代码如下：

<?php 
/** 
* 事件异常 
* 
* @author lonely 
* @create 2010-10-21 
* @version 0.1 
* @lastupdate lonely 
* @package Event 
*/ 
class Exception_Event extends Exception {} 
/** 
* 事件对象 
* 
* @author lonely 
* @create 2010-10-21 
* @version 0.1 
* @lastupdate lonely 
* @package Event 
*/ 
class Event extends stdClass{ 
public $target=null; 
public $type=null; 
/** 
* 创建事件 
* @param string $type 
*/ 
public function __construct($type){ 
$this->type=trim($type); 
} 
/** 
* 得到事件字符串 
*/ 
public function __toString(){ 
return $this->type; 
} 
} 
/** 
* 事件派发 
* 
* @author lonely 
* @create 2010-10-21 
* @version 0.1 
* @lastupdate lonely 
* @package Event 
*/ 
class EventDispatcher{ 
private $_callback_method; 
/** 
* 添加事件 
* @param Event $event 
* @param string $method 
* @param string||object $class 
* @return boolean true 
*/ 
public function attach(Event $event,$method,$class=null){ 
$event->target=$this; 
$eventstr=$this->_create_event_str($event); 
if($this->has($event,$method,$class)) 
return true; 
if($class!=null){ 
$this->_check_method($class,$method); 
$this->_callback_method[$eventstr][]=$this->_create_listener_method($eventstr,$class,$method); 
}else{ 
$this->_check_function($method); 
$this->_callback_method[$eventstr][]=$this->_create_listener_fn($eventstr,$method); 
} 
return true; 
} 
/** 
* 派发事件 
* @param Event $event 
* @param string $method 
* @param string||object $class 
* @return void 
*/ 
public function dispatch(Event $event){ 
$eventstr=$this->_create_event_str($event); 
if($this->_check_callback($eventstr)){ 
foreach ($this->_callback_method[$eventstr] as $v){ 
if($v['object']){ 
if(is_object($v['class'])){ 
$v['class']->$v['method']($event); 
}else{ 
call_user_func(array($v['class'], $v['method']),$event); 
} 
}else{ 
$v['function']($event); 
} 
} 
} 
} 
/** 
* 删除事件 
* @param Event $event 
* @param string $method 
* @param string $class 
* @return boolean true 
*/ 
public function detact(Event $event,$method,$class=null){ 
$eventstr=$this->_create_event_str($event); 
if(!$this->_check_callback($eventstr)) 
return true; 
if(!$this->has($event,$method,$class)) 
return true; 
if($class!=null){ 
$this->_check_method($class,$method); 
foreach ($this->_callback_method[$eventstr] as $k=>$v) { 
if(($v==$this->_create_listener_method($eventstr,$class,$method))){ 
unset($this->_callback_method[$eventstr][$k]); 
return true; 
} 
} 
return true; 
}else{ 
$this->_check_function($method); 
foreach ($this->_callback_method[$eventstr] as $k=>$v) { 
if(($v==$this->_create_listener_fn($eventstr,$method))){ 
unset($this->_callback_method[$eventstr][$k]); 
return true; 
} 
} 
return true; 
} 
} 
/** 
* 检测事件是否监听 
* @param Event $event 
* @param string $method 
* @param string $class 
* @return boolean 
*/ 
public function has(Event $event,$method,$class=null){ 
$eventstr=$this->_create_event_str($event); 
if(($class!=null)){ 
$this->_check_method($class,$method); 
if($this->_check_callback($eventstr)){ 
foreach($this->_callback_method[$eventstr] as $v){ 
if(is_object($v['class'])){ 
$v_class=get_class($v['class']); 
}else{ 
$v_class=$v['class']; 
} 
if(is_object($class)){ 
$s_class=get_class($class); 
}else{ 
$s_class=$class; 
} 
$temp_v=array( 
"class"=>$v_class, 
"method"=>$method, 
); 
$temp_s=array( 
"class"=>$s_class, 
"method"=>$method, 
); 
if($temp_v==$temp_s){ 
return true; 
} 
} 
} 
}else{ 
$this->_check_function($method); 
if($this->_check_callback($eventstr)){ 
foreach($this->_callback_method[$eventstr] as $v){ 
if($method==$v['function']){ 
return true; 
} 
} 
} 
} 
return false; 
} 
/** 
* 检测指定类是否存在指定方法 
* @param string $class 
* @param string $method 
* @exception Exception_Event 
* @return void 
*/ 
private function _check_method($class,$method){ 
if(!method_exists($class,$method)){ 
throw new Exception_Event(get_class($class)." not exist ".$method." method",1); 
} 
} 
/** 
* 检测指定函数是否存在 
* @param string $function 
* @return void 
*/ 
private function _check_function($function){ 
if(!function_exists($function)){ 
throw new Exception_Event($function." function not exist ",2); 
} 
} 
/** 
* 检测指定事件是否存在监听函数 
* @param string $eventstr 
* @return boolean 
*/ 
private function _check_callback($eventstr){ 
if(isset($this->_callback_method[$eventstr]) 
&&is_array($this->_callback_method[$eventstr]) 
){ 
return true; 
} 
return false; 
} 
/** 
* 创建监听函数数组 
* @param string $eventstr 
* @param string $function 
* @return array 
*/ 
private function _create_listener_fn($eventstr,$function){ 
return array( 
"object"=>false, 
"function"=>$function, 
); 
} 
/** 
* 创建监听类数组 
* @param string $eventstr 
* @param string $class 
* @param string $method 
* @return array 
*/ 
private function _create_listener_method($eventstr,$class,$method){ 
return array( 
"object"=>true, 
"class"=>$class, 
"method"=>$method, 
); 
} 
/** 
* 创建事件字符串 
* @param Event $event 
* @return string 
*/ 
private function _create_event_str(Event $event){ 
$classstr=strtolower(get_class($event)); 
$eventstr=(string)$event; 
return $classstr.$eventstr; 
} 
} 
class test extends EventDispatcher{ 

} 
function t($e){ 
print_r($e->a); 
} 
$v=new test(); 
$e=new Event("test"); 
$v->attach($e,"t"); 
$v->detact($e,"t"); 
echo $v->has($e,"t"); 
$e->a="dd"; 
$v->dispatch($e);