PHP event mechanism (2)_PHP tutorial

class Event extends stdClass{
public $target=null;
public $type=null;
/**
* Create event
* @param string $type
*/
public function __construct($type){
$this->type=trim($type);
}
/**
* Get event string
*/
public function __toString(){
return $this->type;
}
}

abstract 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,$method,$class=null){
$eventstr=(string)$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;
}
/**
* dispatch event
* @param Event $event
* @param string $method
* @param string||object $class
* @return void
*/
public function dispatch(Event $event){
$event->target=$this;
$eventstr=(string)$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);
}
}
}
}
/**
* Delete event
* @param Event $event
* @param string $method
* @param string $class
* @return boolean true
*/
public function detact($event,$method,$class=null){
$eventstr=(string)$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;
}
}
/**
* Check whether the event is monitored
* @param Event $event
* @param string $method
* @param string $class
* @return boolean
*/
public function has($event,$method,$class=null){
$eventstr=(string)$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;
}
/**
* Check whether the specified method exists in the specified class
* @param string $class
* @param string $method
* @exception Exception_Event
* @return void
*/
private function _check_method($class,$method){
if(!method_exists($class,$method)){
throw new Exception(get_class($class)." not exist ".$method." method",1);
}
}
/**
* Check whether the specified function exists
* @param string $function
* @return void
*/
private function _check_function($function){
if(!function_exists($function)){
throw new Exception($function." function not exist ",2);
}
}
/**
* Detect whether there is a listening function for the specified event
* @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;
}
/**
* Create an array of listening functions
* @param string $eventstr
* @param string $function
* @return array
*/
private function _create_listener_fn($eventstr,$function){
return array(
"object"=>false,
"function"=>$function,
);
}
/**
* Create listening class array
* @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,
);
}
}



class myevent extends Event{
const aa='aaa';
}
class ball extends EventDispatcher{
public function aa(){
$event=new myevent(myevent::aa);
$this->dispatch($event);
}
}

class mytest {
public function test(){
$ball=new ball();
$ball->attach(myevent::aa,'kk');
$ball->aa();
}
public function kk($e){
print_r($e);
}
}


try{
$t=new mytest();
$t->test();
}catch (Exception $e){
echo $e->getmessage();
}