1 <?php
2 //定义观察者调用接口
3 class transfer{
4 protected $_observers = array();
5
6 //注册对象
7 public function register($sub){
8 $this->_observers[] = $sub;
9 }
10
11 //外部统一调用
12 public function trigger(){
13 if(!empty($this->_observers)){
14 foreach($this->_observers as $observer){
15 $observer->update();
16 }
17 }
18 }
19 }
20
21 //观察者接口
22 interface obserable{
23 public function update();
24 }
25
26 //实现观察者
27 class listen implements obserable{
28 public function update(){
29 echo 'now first time you need to do listen<br/>';
30 }
31 }
32
33 class read implements obserable{
34 public function update(){
35 echo 'now first time you need to read<br/>';
36 }
37 }
38
39 class speak implements obserable{
40 public function update(){
41 echo 'now first time you need to speak<br/>';
42 }
43 }
44
45 class write implements obserable{
46 public function update(){
47 echo 'now first time you need to write<br/>';
48 }
49 }
50
51 $transfer = new transfer();
52 $transfer->register(new listen());
53 $transfer->register(new read());
54 $transfer->register(new speak());
55 $transfer->register(new write());
56 $transfer->trigger();
