Make a gameObject follow another gameObject's behavior? - unity3d

Question

I am controlling a text GameObject. I am performing operations such as SetActive() and changing the text of the gameObject. Now I am duplicating the same object and I want the duplicated object to follow the behaviors of its main gameObject. That is ObjA is parent and ObjB is a clone. If I change the text UI through code of objA, I want objB to automatically change its component. How do I achieve this behavior?

Answer 1

There are multiple ways to do that, but it will always be by code, there is no "authomatism" to do that.
So by code you can make a relation child to parent or parent to child.
One way could be that one:
public class Parent : MonoBehaviour
{
public Child child = null;
public void DoSomething()
{
this.gameObject.SetActive(true);
child.DoSomething();
}
}
public class Child : MonoBehaviour
{
public void DoSomething()
{
this.gameObject.SetActive(true);
}
}
Another fancy way to do that is using delegates, or Actions:
public class Parent : MonoBehaviour
{
public Action OnDoSomething = null;
public Action OnDoSomethingElse = null;
public void DoSomething()
{
this.gameObject.SetActive(false);
OnDoSomething();
}
public void DoSomethingElse()
{
this.gameObject.SetActive(true);
OnDoSomethingElse();
}
}
public class Child : MonoBehaviour
{
public Parent parent = null;
public void Awake()
{
parent.OnDoSomething += ChildDoSometing;
parent.OnDoSomethingElse += ChildDoSometingElse;
}
public void OnDestroy()
{
parent.OnDoSomething -= ChildDoSometing;
parent.OnDoSomethingElse -= ChildDoSometingElse;
}
public void ChildDoSometing()
{
this.gameObject.SetActive(false);
}
public void ChildDoSometingElse()
{
this.gameObject.SetActive(false);
}
}
You can be tempted to pass your own method as Action parameter like Action<Action> but remember that child will call parent method, won't operate on his own. So in this case if you do something like:
public class Parent : MonoBehaviour
{
public Action<Action> OnDoSomething = null;
[ContextMenu("A")]
public void DoSomething()
{
this.gameObject.SetActive(true);
OnDoSomething(this.DoSomething);
}
public void DoSomethingElse()
{
print("Hello");
}
}
public class Child : MonoBehaviour
{
public Parent parent = null;
public void Awake()
{
parent.OnDoSomething += RepeatedAction;
}
public void OnDestroy()
{
parent.OnDoSomething -= RepeatedAction;
}
public void RepeatedAction(Action actionToRepeat)
{
actionToRepeat?.Invoke();
}
}
Will result on StackOverflow exception, cause child will call parent, who calls child, who calls again parent...you can see the problem.
Anyway would be nice to declare an abstract base class that have all the methods, and let both classes inherit from that class, and implement those methods.