Client observer

gistfile1.aw

<?php

class ServiceClient implements SplSubject {
    
    private $service;
    private $http;
    private $observers;
    
    public function __construct(Service $service, Http $http) {
        $this->service = $service;
        $this->http = $http;
    }
    
    public function getService() {
        return $this->service;
    }

    public function setService(Service $service) {
        $this->service = $service;
    }
    
    public function call() {
        $this->http->setUrl($this->service->getUrl());
        $this->http->setMethod($this->service->getMethod());
        $this->http->setBody($this->service->getBody());
        $this->http->send();
        $this->notify();
        return $this->http->getResponseBody();
    }
    
    public function attach(SplObserver $observer) {
        $this->observers[spl_object_hash($observer)] = $observer;
    }
    
    public function detach(SplObserver $observer) {
        unset($this->observers[spl_object_hash($observer)]);
    }
    
    private function notify() {
        foreach ($this->observers as $observer) {
            $observer->update($this);
        }
    }
}

In the example the call to the logging method was at that point, that is why I left the notify() call in the same place. However you are completely right, the later on we put the call to notify(), the more information is available to the observer. I've updated the example, thanks.