Editor Scripting Object added to scene

Unity Engine
1

Hi I am trying to find out if there is a function that is called when an object is dragged and dropped into a scene in the editor.

I need to run some code once when each object is added.

The editor scripting documentation is pretty thin.

2

ok i found a rather horrible way of doing what I wanted. I created a script that goes through every item in every scene and assigns them a unique ID. I’m still interested in the answer to my original question though.

using UnityEngine;
using UnityEditor;
using System.Collections;

public class SetUI : MonoBehaviour 
{
	static int id = 1;
	
	[MenuItem ("GameObject/Assign All Items Unique IDS")]
	static void SetItemUIS()
	{
		
		UnityEditor.EditorBuildSettingsScene[] allScenes = EditorBuildSettings.scenes;
		
		// loop through all the scenes
		foreach(UnityEditor.EditorBuildSettingsScene scene in allScenes)
		{
		
			// open scenes 
			 EditorApplication.OpenScene(scene.path);
			
			//find all Items in each scene
			GameObject[] items = GameObject.FindGameObjectsWithTag("Item");
			 foreach (GameObject item in items) 
			{
				// assign each a unique ID
				Item itemScript = item.GetComponent<Item>() as Item;

				itemScript.itemID = id;
				
				Debug.Log(item.name + " " + id.ToString());
				
				// increment id
				id++;
			}
		}
	}
}