Losing references made in editor script

Questions & Answers
1

Hi

I am trying to learn editor scripting, and I am experiencing stuff that I find weird, which probably because I don’t understand how Unity works.

I am trying to create a grid of GameObjects. I would like to store references to the created GameObjects in a Dictionary (or a two dimensional array), but it seems like I lose the references when going from editor mode to game mode/running the game.

I have tried to make a small code example to show my problem:

using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class GridHandler : MonoBehaviour {

    public GameObject gameObject;
    public List<GameObject> list = new List<GameObject>();
    public Dictionary<string, GameObject> dictionary = new Dictionary<string, GameObject>();
	
    void Start(){
        //Using Start() to test in "game mode"
        //I would like to use the references to the gameObjects that I generated in createGrid.
        Debug.Log("Start");
        Debug.Log(gameObject.transform.name);
        Debug.Log(list[0].transform.name);
        Debug.Log(dictionary["a"].transform.name); //This call gives error "KeyNotFoundException"
    }
     
    //This function is called from an editor script in "editor mode"
    public void createGrid(){
        //Clearing just for testing
        list.Clear();
        dictionary.Clear();
        
        gameObject = new GameObject();
        gameObject.transform.name = "1 - gameObject";
       
        list.Add(new GameObject());
        list[0].transform.name = "2 - list";

        dictionary.Add("a", new GameObject());
        dictionary["a"].transform.name = "3 - dictionary";

        Debug.Log(gameObject.transform.name);
        Debug.Log(list[0].transform.name);
        Debug.Log(dictionary["a"].transform.name);
    }
}

In the Console i get:

(createGrid called)

1 - gameObject

2 - list

3 - dictionary

(running program)

1 - gameObject

2 - list

Error (KeyNotFound)

I could store the grid in a list and let each gameObject know its position, it just doesn’t seem optimal, and I would like to understand why I can’t use a Dictionary.
It seems like I have the same problem when using dynamically generated two-dimensional arrays.

Please ask if I havn’t explained my problem precisely.

Best wishes
Hans Larsen

2

Dictionaries aren’t serialized when changing play modes. There are ways around it, either transform your dictionary to two lists (which are serialized by Unity) and rebuilding the dictionary on entry to Game Mode (like explored in this question) or create a custom serializer that handles your data. The asset store has a few of those.