PHP オブザーバー パターンの例を使ってみる

class DemoSubject は SplSubject を実装します{
 private $observers, $value;

 public function __construct(){
 $this->observers = array();
 }

 public functionattach(S plObserver $observer) {
 $this->observers[] = $observer;
 }

 public function detach(SplObserver $observer){
 if($idx = array_search($observer, $this->observers, true)){
 unset($this->observers[$idx]);
 }
 }

 public function Notice(){
 foreach($this->observers as $observer){
 $observer->update($this );
 }
 }

 public function setValue($value){
 $this->value = $value;
 $this->notify();
 }

 public function getValue(){
 $を返すthis->value;
 }
}

class DemoObserverimplements SplObserver{
 public function update(SplSubject $subject){
 echo '新しい値は ' です。 $subject->getValue();
 }
}

$subject = new DemoSubject();
$observer = new DemoObserver();
$subject->attach($observer);
$subject-> setValue(5);