Values added during editor mode are removed when starting playmode

Questions & Answers
1

I have nodes in my game, that have a List filled with connected nodes. I don’t want to manually add nodes to each other with drag and drop, but I want to connect all nodes that are currently selected in the editor. I wrote this script:

	[MenuItem("Node Tools/Connect Selected Nodes %g")]
	static void ConnectSelectedNodes() {
		List<AbstractNode> selectedNodes = new List<AbstractNode>();

		foreach (GameObject n in Selection.gameObjects) {
			if (n.GetComponent<AbstractNode>() != null) {
				selectedNodes.Add(n.GetComponent<AbstractNode>());
			}
		}

		Debug.Log(selectedNodes.Count);

		foreach (AbstractNode n in selectedNodes) {
			foreach (AbstractNode c in selectedNodes) {
				if (n.gameObject != c.gameObject) {
					Undo.RecordObject(n, "Added connection");
					n.AddConnection(c);
				}
			}
		}
	}

The connection gets added in the inspector, but when I press play, every field in the array switches to “null” and stays like that after stopping the game.

I hope you guys can help me with this problem.

2

It would be good to see your AbstractNode class.

When calling n.AddConnection(c), are you changing any private variables, say, adding the other node to a list? Any fields you change must have an attribute [SerializeField] in front of it, or the changes won’t be saved for runtime.

If AbstractNode is a struct or a class instead of a MonoBehaviour script, it might also need to have the attribute [System.Serializable]. This makes the values appear in the Inspector, and I think it allows changes to be saved.

3

Does the object in question come from a prefab with values of its own?