Gets a string that represents the name of the action that will be performed when a call to the undo method is made. The property's value is null if there is no action that can be undone.
<void> TXTextControl.getUndoActionName(<RequestStringCallback> callback, [<ErrorCallback> errorCallback])
|callback||The callback function that receives the requested value.|
||Optional. Is called when the operation failed with an error.|