PHP watcher pattern - good practice for different events

Question

I would like to know if my implementation of the Observer template is correctly implemented for different events, such as ' userLoggedOut', ' userRegistered', ' userLoggedIn'. Below is my simplified code:

index.php

$login = new \Observer\Observable\Login;
$userData = $login->getData();

$login->attach( new \Observer\Observer\Email );

$login->notify( 'userLoggedIn' );
$login->notify( 'userLoggedOut', $userData );
$login->notify( 'userRegistered' );

login.php

namespace Observer\Observable;
use Observer\Interfaces;

class Login implements Interfaces\Observable {

    private $observers = array();

    function attach( Interfaces\Observer $object ) {

        $this->observers[] = $object;

    }

    function getObservers() {

        return $this->observers;

    }

    function notify( $action, $data = null ) {

        foreach( $this->observers as $observer ) :

            if( method_exists( $observer, $action ) ) $observer->$action( $data );

        endforeach;

    }

}

email.php

namespace Observer\Observer;
use Observer\Interfaces;

class Email implements Interfaces\Observer {

    function userLoggedIn( $data = null ) {

        echo "email user logged in";

    }

    function userLoggedOut( $data = null ) {

        echo "email user logged out";

    }

    function userRegistered( $data = null ) {

        echo "email user registered";

    }

}

My question is, are there any better ways to implement the Observer pattern when working with multiple actions.

Answer 1

, , . Observable ( - , , . , , , , Login, , , . Login , .

, , - , :

class Observable {
    protected static $event_names = array();
    protected $observers = array();

    function __construct() {
        foreach (static::$event_names as $event_name) {
            $this->observers[$event_name] = array();
        }
    }

    function register($event, $object, $handler) {
        if (array_key_exists($event, $this->observers)) {
            $this->observers[$event][] = array($object, $handler);
        } else {
            echo "Invalid event \"$event\"!";
        }
    }

    function trigger($event, $data = null) {
        foreach ($this->observers[$event] as $observer) {
            $observer[0]->$observer[1]($data);
        }
    }
}

class Login extends Observable {
    protected static $event_names = array("userLoggedIn", "userLoggedOut", "userRegistered");
}

:

class SomeListener {
    function __construct() {
        $login_instance->register("userLoggedIn", $this, "myLoggedInHandler");
    }

    function myLoggedInHandler($data = null) {
        echo "User Logged In.";
    }
}

, , , ( , Observable IMO).