Observer

Subject.cs

using System.Collections.Generic;
using UnityEngine;

//Invokes the notificaton method
public class Subject : MonoBehaviour
{
    //A list with observers that are waiting for something to happen
    public List<Observer> observers = new List<Observer>();

    private void Start()
    {
        Notify();
    }

    //Send notifications if something has happened
    public void Notify()
    {
        foreach (var observer in observers)
        {
            //Notify all observers even though some may not be interested in what has happened
            //Each observer should check if it is interested in this event
            observer.OnNotify();
        }
    }

    //Add observer to the list
    public void AddObserver(Observer observer)
    {
        observers.Add(observer);
    }

    //Remove observer from the list
    public void RemoveObserver(Observer observer)
    {
    }
}