Is there a way to automatically prevent redundant monobehaviours (a la colliders?)

When you try to add a Collider to a GameObject that already has one, Unity won't let you. Is there any way to put the same restrictions on a custom MonoBehaviour? Right now I'm doing some pretty hacky stuff in the MonoBehaviour's Awake() to work around it in play mode, but it'd be nice if I could just stop it from ever happening, especially within edit mode. There really ought to be an attribute for it (maybe something for the wish list.)

 

well, i got my hack good enough that i'm happy with it, although it will only work if you can get away with using [ExecuteInEditMode]. here it is, if anyone wants it:

Code (csharp):

1.  
2.  
3. [ExecuteInEditMode]
4. public class MyMonoBehaviour : MonoBehaviour {
5.  
6. void Awake ()
7.     {
8.         MyMonoBehaviour[] localInstances = gameObject.GetComponents<MyMonoBehaviour>();
9.        
10.         if (localInstances.Count() > 1) {
11.                 Debug.Log ("Can't add component 'MyMonoBehaviour' to " + this.gameObject.name + "because such a component is already added to the game object!");
12.             StartCoroutine(DestroyNextFrame());
13.            
14.         }
15.         else
16.         {
17.             //whatever you'd do otherwise
18.         }
19.     }
20.    
21.     IEnumerator DestroyNextFrame ()
22.     {
23.         yield return 1;
24.         DestroyImmediate (this);
25.     }

the use of a coroutine seems necessary to prevent this apparently harmless but annoying error that obscures the Debug message:

Code (csharp):

1. m_InstanceID == 0
2. UnityEditorInternal.InternalEditorUtility:InspectorWindowDrag(Object, Boolean)
3. UnityEditor.DockArea:OnGUI()