# OnOpenAssetAttributeMode

> Indicates whether OnOpenAssetAttribute decorated method is a validation function that checks if asset opening is handled by Unity or a custom script.

## Definition

* **Type:** Enum
* **Namespace:** [UnityEditor.Callbacks](/engine/6000.7/script-reference/unityeditor/callbacks.md)
* **Assembly:** UnityEditor.CoreModule

```csharp
public enum OnOpenAssetAttributeMode
```

## Fields

| Value                                                                                                  | Description                                                                                                                                                     |
| ------------------------------------------------------------------------------------------------------ | --------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [Execute](/engine/6000.7/script-reference/unityeditor/callbacks/onopenassetattributemode/execute.md)   | Indicates that [OnOpenAssetAttribute](/engine/6000.7/script-reference/unityeditor/callbacks/onopenassetattribute.md) decorated method is an opening function.   |
| [Validate](/engine/6000.7/script-reference/unityeditor/callbacks/onopenassetattributemode/validate.md) | Indicates that [OnOpenAssetAttribute](/engine/6000.7/script-reference/unityeditor/callbacks/onopenassetattribute.md) decorated method is a validation function. |