Detect if an object has been disconnected from its clients - vba

Question

I am having an issue with automating an Excel file. The VBA script within Excel first opens a Word application and Word document:
Dim wordApp As Object
Set wordApp = CreateObject("Word.Application")
vPath = Application.ActiveWorkbook.Path
Set wordDoc = wordApp.Documents.Open(vPath & "\test.doc")
And then I call a subroutine within the Word document passing some data from the Excel file:
Call wordApp.Run("StartWithData", variable1, variable2)
If Excel detects that an error occurs in that subroutine, I close the Word document and Word application from Excel in a label I call Err1:
On Error Goto Err1
'all the code from above
Exit Sub
Err1:
wordDoc.Close wdCloseWithoutSaving
wordApp.Quit SaveChanges:=wdDoNotSaveChanges
Set wordDoc = Nothing
Set wordApp = Nothing
This works perfectly fine under normal circumstances; however, if the Word document or application are closed before the Err1 label executes (such as the user manually closing the document), I get the following error:
Run-time error '-2147417848 (80010108)':
Automation error The object invoked has disconnected from its clients.
which makes perfect sense because the wordApp and/or wordDoc variables still reference the Application and Document objects and those objects do not exist anymore (yet are also not considered to be Nothing).
So here is my inquiry: Is there a way to check if an object has been disconnected from its client before the run-time error occurs so as to avoid having to rely on on error resume next?
Such as:
If Not isDisconnected(wordDoc) Then
wordDoc.Close wdCloseWithoutSaving
End If
If Not isDisconnected(wordApp) Then
wordApp.Quit SaveChanges:=wdDoNotSaveChanges
End If
Update 1:
After looking at omegastripes' answer, I realized that the error given above only occurs when the document (wordDoc) was the object that got disconnected. If the Word application (wordApp) is what got disconnected, I get the following error:
Run-time error '462':
The remote server machine does not exist or is unavailable

Answer 1

Consider the below example:
Sub Test()
Dim wordApp As Object
Dim wordWnd As Object
Dim wordDoc As Object
Set wordApp = CreateObject("Word.Application")
Set wordWnd = wordApp.Windows ' choose any object property as indicator
wordApp.Visible = True ' debug
Set wordDoc = wordApp.Documents.Open(Application.ActiveWorkbook.Path & "\test.doc")
MsgBox IsObjectDisconnected(wordWnd) ' False with opened document
wordDoc.Close
MsgBox IsObjectDisconnected(wordWnd) ' False with closed document
wordApp.Quit ' disconnection
MsgBox IsObjectDisconnected(wordWnd) ' True with quited application
End Sub
Function IsObjectDisconnected(objSample As Object) As Boolean
On Error Resume Next
Do
IsObjectDisconnected = TypeName(objSample) = "Object"
If Err = 0 Then Exit Function
DoEvents
Err.Clear
Loop
End Function
Seems any type detection of the variable, which references to the intrinsic Word objects, like .Documents, .Windows, .RecentFiles, etc., made immediately after document close or application quit commands have been invoked, may throw the error 14: Out of string space, while Word application processing the command. The same detection on the Applicationobject , may also hang Excel application.
In the example TypeName() call is wrapped into OERN loop, that should skip irrelevant results to get explicit disconnection feedback, relying on the type name, but not on the error number. To avoid hanging, .Windows property is being checked instead of Application.