ExecuteInEditMode

Description

Makes all instances of a script execute in Edit Mode.

By default, MonoBehaviours are only executed in Play Mode. By adding this attribute, any instance of the MonoBehaviour will have its callback functions executed while the Editor is in Edit Mode too.

This attribute is being phased out since it does not take Prefab Mode into account. If a Prefab with a MonoBehaviour with this attribute on is edited in Prefab Mode, and Play Mode is entered, the Editor will exit Prefab Mode to prevent accidental modifications to the Prefab caused by logic intended for Play Mode only.

To indicate that a MonoBehaviour correctly takes Prefab Mode into account and is safe to have open in Prefab Mode while in Play Mode, the attribute ExecuteAlways can be used instead of the attribute here.

The functions are not called constantly like they are in Play Mode.
- Update is only called when something in the Scene changed.
- Awake is only called when the script is instanced.
- OnGUI is called when the Game View receives a non-editor-only Event that it does not use (e.g., EventType.ScrollWheel) and does not forward to the Editor's keyboard shortcut system (e.g., EventType.KeyDown, EventType.KeyUp). Events forwarded to the Game View are enqueued and are not guaranteed to be processed immediately.
- OnRenderObject and the other rendering callback functions are called on every repaint of the Scene View or Game View.

See Also: ExecuteAlways, Application.IsPlaying, runInEditMode, EditorApplication.QueuePlayerLoopUpdate.

// The PrintAwake script is placed on a GameObject.  The Awake function is usually
// called when the GameObject is started at runtime.  Due to the ExecuteInEditMode
// attribute, the script is also called by the Editor.  The Awake() function will be called,
// for example, when the Scene is changed to a
// different Scene in the Project window.
// The Update() function is called, for example, when the GameObject transform
// position is changed in the Editor.

using UnityEngine;

[ExecuteInEditMode]
public class PrintAwake : MonoBehaviour
{
    void Awake()
    {
        Debug.Log("Editor causes this Awake");
    }

    void Update()
    {
        Debug.Log("Editor causes this Update");
    }
}