[ Posted by Fillano ] simple Event Facilities.

fiddle_032932.php

<?php
class Event {
    private static $events = [];
    public static function Regist($eventName, Callable $callback) {
        if(!is_callable($callback)) return false;
        if(!array_key_exists($eventName, self::$events)) {
            self::$events[$eventName] = [];
        }
        self::$events[$eventName][] = $callback;
        return true;
    }
    public static function Trigger($eventName, $eventData) {
        if(!array_key_exists($eventName, self::$events)) return false;
        foreach(self::$events[$eventName] as $c) {
            call_user_func($c, $eventData);
        }
    }
}

class Test001 {
    private $name;
    function __construct($name) {
        $this->name = $name;
    }
    public function greeting($data) {
        echo $data . " " . $this->name . "<br>\n";
    }
}

$a = new Test001("Fillano");
$b = new Test001("Hildegard");
Event::Regist("event1", [$a, "greeting"]);
Event::Regist("event1", [$b, "greeting"]);
Event::Trigger("event1", "Hello World");
?>