The OnUndo event notifies a client when an undo operation is being performed.
| Name | Type | Description |
| TransactionObject | Transaction | The Transaction object being undone. |
| Context | NameValueMap | Input object that can be used to determine the context of why the event fired. No context information is provided for this event. |
| BeforeOrAfter | EventTimingEnum | Input indicating when the event is being fired. Notification is sent before and after the transaction is undone. |
| HandlingCode | HandlingCodeEnum | Output that indicates how you are handling the event. This argument is ignored for this event. |