gistfile1.php

<?php

class SmsNotificationObserver implements SplObserver
{
    public function update(SplSubject $subject)
    {
        $this->sendSms($subject->getNews());
    }

    private function sendSms($news)
    {
        echo "wysylam sms z nowa wiadomoscia $news<br>";
    }
}

class EmailNotificationObserver implements SplObserver
{
    public function update(SplSubject $subject)
    {
        $this->sendEmail($subject->getNews());
    }

    private function sendEmail($news)
    {
        echo "wysylam email z nowa wiadomoscia $news<br>";
    }
}

class NewsModelObserver implements SplObserver
{
    public function update(SplSubject $subject)
    {
        $this->addToDb($subject->getNews());
    }

    private function addToDb($news)
    {
        echo 'dodaje newsy do bazy danych<br>';
    }
}

class NewsDownloader implements SplSubject
{
    private $observers = array();

    public function attach(SplObserver $observer)
    {
        $this->observers[spl_object_hash($observer)] = $observer;
    }

    public function detach(SplObserver $observer)
    {
        unset($this->observers[spl_object_hash($observer)]);
    }

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

    public function updateNews($news)
    {
        $this->news = $news;
        $this->notify();
    }

    public function getNews()
    {
        return $this->news;
    }
}

$newsDownloader = new NewsDownloader();

$smsNotification = new SmsNotificationObserver();
$emailNotification = new EmailNotificationObserver();
$dbModel = new NewsModelObserver();

$newsDownloader->attach($dbModel);
$newsDownloader->attach($emailNotification);
$newsDownloader->attach($smsNotification);

$newsDownloader->updateNews('Zamknieto baze w USA');
$newsDownloader->updateNews('Polska jest mocarstwem');
$newsDownloader->detach($smsNotification);
$newsDownloader->updateNews('Reprezentacja Polski w pilce noznej wygrywa');