觀察者模式

<?php
	/**
	 * Created by PhpStorm.
	 * User: Administrator
	 * Date: 2016/6/27
	 * Time: 23:20
	 */
	abstract class EventGenerator{
		private $observers = array();
		function addObserver(Observer $observer){
			$this->observers[] = $observer;
		}
		function  notify(){
			foreach($this->observers as $observer){
				$observer->update();
			}
		}
	}

	interface Observer{
		function update($event_info = NULL);
	}

	class Observer1 implements Observer{
		function update($event_info = NULL)
		{
			// TODO: Implement update() method.
			echo '觀察者1<br>';
		}
	}

	class Observer2 implements Observer{
		function update($event_info = NULL)
		{
			// TODO: Implement update() method.
			echo "觀察者2<br>";
		}
	}
	class Event extends EventGenerator{
		function trigger(){
			echo "Event<br>\n";
			$this->notify();
			////邏輯1
			//echo "邏輯1<br>";
			////邏輯3
			//echo "邏輯2<br>";
			////邏輯3
			//echo "邏輯3<br>";
		}
	}
	$event = new Event();
	$event->addObserver(new Observer1());
	$event->addObserver(new Observer2());
	$event->trigger();