---
title: willUndoChange
framework: foundation
role: symbol
role_heading: Type Property
path: foundation/notificationcenter/messageidentifier/willundochange
---

# willUndoChange

An identifier for a message about an undo manager preparing to perform an undo.

## Declaration

```swift
static var willUndoChange: NotificationCenter.BaseMessageIdentifier<UndoManager.WillUndoChangeMessage> { get }
```

## Discussion

Discussion Use this identifier with NotificationCenter’s addObserver(of:for:using:) or messages(of:for:bufferSize:) methods to observe messages of type UndoManager.WillUndoChangeMessage.

## See Also

### Identifying undo manager messages

- [didUndoChange](foundation/notificationcenter/messageidentifier/didundochange.md)
- [willRedoChange](foundation/notificationcenter/messageidentifier/willredochange.md)
- [didRedoChange](foundation/notificationcenter/messageidentifier/didredochange.md)
- [checkpoint](foundation/notificationcenter/messageidentifier/checkpoint.md)
- [didOpenUndoGroup](foundation/notificationcenter/messageidentifier/didopenundogroup.md)
- [willCloseUndoGroup](foundation/notificationcenter/messageidentifier/willcloseundogroup.md)
- [didCloseUndoGroup](foundation/notificationcenter/messageidentifier/didcloseundogroup.md)