access a gameobject from another scene at design-time

Questions & Answers
1

I’ll try to describe my problem as clear as possible.

I have a baseclass that references other monobehaviour scripts attached to a gameobject in my scene.
If I use dontdestroyonload() I can still access that gameobject from my other scenes at run-time since it’s not destroyed upon scene loading.

But at design-time I’d like to be able to playtest my scenes separately, obviously I get a null-reference exception since the gamobject don’t exist in that scene.
I guess I could simply add the same gameobject to each and every of my scenes, and then remove all, but one before run-time.

My question is if there are another way of doing this? like a dontdestroyonload() but for design-time?

Best regards!

2

For testing like this I would have a script in each scene check for the object when the scene loads, if the object isn’t there you instantiate it. So in normal usage the scene uses the existing object from the previous scene, but when play testing the scene the object is there also.

3

Make the object a singleton and have one instance in every scene, but destroy the other instances at runtime in the Awake methods. Something like this:

public class MyBehaviour : MonoBehaviour
{
        private static MyBehaviour _instance = null;
        public static MyBehaviour Instance
        {
            get
            {
                if (_instance == null)
                {
                    _instance = (new GameObject("MyBehaviour")).AddComponent<MyBehaviour>();
                }

                return _instance;
            }
        }

        void Awake()
        {
            if (_instance == null)
            {
                _instance = this;
                DontDestroyOnLoad(this);

                // perform initialization
            }
            else
            {
                // singleton implementation that ensures only one instance in scene
                if (FindObjectsOfType(typeof(MyBehaviour)).Length > 1)
                {
                    DestroyImmediate(gameObject);
                }
            }
        }
}

This way you can start the game from every scene and have the object there.