Traffic Signal System: observer design pattern improper usage

[siddharthmagadum16]

Hi Ashish, I was going through LLD of Traffic Signal System. The design uses observer pattern, but I think that this is slightly misimplemented.


The Code here, i.e. notifyObservers() should not be present in TrafficLight entity.

Rather, it should be called in TrafficController entity, as it has the list of Roads (indirectly TrafficLights) and acts as a subject to infrom all TrafficLights about the signal color update of each of them.

In short, `notifyObservers()` method should be a part of TrafficController and `listenTrafficEvent()/changeColor()` should be part of TrafficLight.