PHP event example

event.php

<?php

class Event
{
    public function fire($event, $params = NULL)
    {
        return call_user_func($this->{"on".ucfirst($event)});
    }
}

$event = new Event;

// define events
$event->onLogin = function()
{
    return "Yes logged in";
};

// define events
$event->onLogOut = function()
{
    return "Yes logged out";
};


// fire the event
echo $event->fire("login");
echo $event->fire("logOut");