PHP의 위임 모델 및 이벤트 전달 메커니즘 분석

class Delegate { private $delegate; public function setDelegate($delegate) { $this->delegate = $delegate; } public function performTask() { if ($this->delegate) { $this->delegate->__invoke(); // 使用匿名函数调用委托对象的方法 } else { echo "No delegate set "; } } } $delegate1 = function() { echo "Delegate 1 is performing task "; }; $delegate2 = function() { echo "Delegate 2 is performing task "; }; $delegation = new Delegate(); $delegation->performTask(); // 输出"No delegate set" $delegation->setDelegate($delegate1); $delegation->performTask(); // 输出"Delegate 1 is performing task" $delegation->setDelegate($delegate2); $delegation->performTask(); // 输出"Delegate 2 is performing task"

class EventSubject implements SplSubject { private $observers; // 所有观察者对象 private $data; // 事件的相关数据 public function __construct() { $this->observers = new SplObjectStorage(); } public function attach(SplObserver $observer) { $this->observers->attach($observer); } public function detach(SplObserver $observer) { $this->observers->detach($observer); } public function notify() { foreach ($this->observers as $observer) { $observer->update($this); } } public function setData($data) { $this->data = $data; } public function getData() { return $this->data; } } class EventObserver implements SplObserver { public function update(SplSubject $subject) { $data = $subject->getData(); echo "Event occurred: $data "; } } $subject = new EventSubject(); $observer1 = new EventObserver(); $observer2 = new EventObserver(); $subject->attach($observer1); $subject->attach($observer2); $subject->setData("Event 1"); $subject->notify(); // 输出"Event occurred: Event 1" $subject->detach($observer1); $subject->setData("Event 2"); $subject->notify(); // 输出"Event occurred: Event 2"