MS-Word: How to work around oddity in Range.WordOpenXML?

Question

Retrieving the value of property Range.WordOpenXML (VBA, interop) ruins the recording of a custom undo record and also the undo stack:

Public Sub Test()
  Dim xml As String

  ShowState                                       ' 0
  
  Selection.Font.StrikeThrough = wdToggle
  ShowState                                       ' 0
  
  Application.UndoRecord.StartCustomRecord "Foo"
  ShowState                                       ' 1 Foo
  
  Selection.Font.Bold = wdToggle
  ShowState                                       ' 1 Foo
  
  xml = Selection.Range.WordOpenXML
  ShowState                                       ' 1
  
  Selection.Font.Italic = wdToggle
  ShowState                                       ' 1

  Application.UndoRecord.EndCustomRecord
  ShowState                                       ' 0
End Sub

Private Sub ShowState()
  Debug.Print Application.UndoRecord.CustomRecordLevel; _
              Application.UndoRecord.CustomRecordName
End Sub

Consequences of running Test() are:

• Okay: The reported custom record levels seem to be correct.
• Okay: There is an undo record for the StrikeThrough.
• Wrong: The custom record name is dropped by retrieving WordOpenXML.
• Okay: Both italic and bold font settings have been toggled, too.
• Wrong: As far as visible the undo stack seems to contain only the entry for the StrikeThrough, but nothing for the actions collected in the custom record.
• Wrong: Clicking the undo button once(!) undoes all changes, i.e. all three actions, both undo records.
• Okay: The undo button is deactivated after the aforementioned click, obviously because there are no further undoable actions.

If you comment out the line toggling the StrikeThrough, things become even more weird:

• Okay: The reported custom record levels seem to be correct.
• Wrong: The custom record name is dropped by retrieving WordOpenXML.
• Okay: Both italic and bold font settings have been toggled, too.
• Wrong: the undo stack seems to not contain any entry even though the undo button is not deactivated (as it would be if the undo stack was empty).
• Wrong: Clicking the undo button then undoes only the toggling of the italics, i.e. the two font toggles cannot have been gathered in the custom undo record even though the nesting levels seem to state this.
• Wrong: The undo button is deactivated after the aforementioned click, obviously because there are no further undoable actions. -> The toggling of the bold font cannot be undone anymore.

If, however, you uncomment the line retrieving the WordOpenXML, everything works as expected.

Note: In a VSTO / Interop environment I also had the case that - unlike this example - the CustomRecordLevel was reset to 0 by WordOpenXML.

We'd be grateful for suggestions on how to avoid this odd behaviour or how to work around / correct it.

Best regards,

J.K.

Answer 1

Stopping then restarting the recording worked for me in VSTO, didn't tried on VBA but something like this should do the trick :

  Dim xml As String
  Dim recordName As String

  recordName = Application.UndoRecord.CustomRecordName
  Application.UndoRecord.EndCustomRecord

  xml = Selection.Range.WordOpenXML

  Application.UndoRecord.StartCustomRecord recordName

After this we still have 1 record