Observer Design Pattern

The observer is an architectural pattern, where objects register to get notified when events happen to a specific object. It is also known as the listener pattern.

There is a native interface call SplObserver, coupled with the SplSubject, to implement such pattern.

Documentation

See also SplSubject, Events and Event Listeners and Observer Pattern In PHP 8+.

Related : Design Pattern, Listener, Observer Pattern, Pub/Sub, SplObserver