Changing text in a contentcontrol is very slow - vba

Question

I have a big table in ms-word that contains 85 contentcontrols (combo boxes). I want to change the content using a vba loop (see below). It takes longer than one minute for it to complete...
Are there other options?
Private Sub Btn_Clear1_Click()
Dim a
Dim c As ContentControl
a = FindTable(ActiveDocument.Name, "myTableName")(1) 'returns an array(Long) with number of table found
For Each c In ActiveDocument.Tables(a).Range.ContentControls
c.Range.text = "MY CHANGED TEXT"
Next c
End Sub
Thanks in advance for any hint!

Answer 1

Here, turning off screenupdating reduces the time from about 6 seconds to less than 1 second. e.g.
On Error Goto turnscreenon
Application.Screenupdating = False
For Each c In ActiveDocument.Tables(a).Range.ContentControls
c.Range.text = "MY CHANGED TEXT"
Next c
turnscreenon:
Application.Screenupdating = True
That may only work on the Windows version of Word.
If you know exactly how many combo boxes there are going to be, you could consider creating a custom xml part containing an array of XML Elements to contain the values. Map each content control to one of those elements. Then instead of writing the values to the content control ranges, write them to the XML Part and let Word do the work. That works almost instantaneously here.
e.g. in a simple scenario where you just have those 85 content controls in the table, you could set up the Custom XML Part like this (I leave you to write any code that you need to delete old versions). You should only need to run this once.
Sub createCxpAndLink()
' You should choose your own Uri
Const myNamespaceUri As String = "mycbcs"
Dim a
Dim i As Long
Dim s As String
Dim cxp As Office.CustomXMLPart
With ActiveDocument
a = FindTable(.Name, "myTableName")(1)
s = ""
s = s & "<?xml version='1.0' encoding='UTF-8'?>" & vbCrLf
s = s & "<cbcs xmlns='" & myNamespaceUri & "'>" & vbCrLf
For i = 1 To .Tables(a).Range.ContentControls.Count
s = s & " <cbc/>" & vbCrLf
Next
s = s & "</cbcs>"
Set cxp = .CustomXMLParts.Add(s)
With .Tables(a).Range.ContentControls
For i = 1 To .Count
.Item(i).XMLMapping.SetMapping "/x:cbcs[1]/x:cbc[" & Trim(CStr(i)) & "]", "xmlns:x='" & myNamespaceUri & "'", cxp
Next
End With
Set cxp = Nothing
End With
End Sub
Then to update the contents you need something like this
Sub testsetxml()
Const myNamespaceUri As String = "mycbcs"
Dim i As Long
'our start time...
Debug.Print Now
With ActiveDocument.CustomXMLParts.SelectByNamespace(myNamespaceUri)(1)
For i = 1 To 85
.SelectNodes("/ns0:cbcs[1]/ns0:cbc[" & Trim(CStr(i)) & "]")(1).Text = "my changed text "
' or if you want to put different texts in different controls, you can test using e.g.
.SelectNodes("/ns0:cbcs[1]/ns0:cbc[" & Trim(CStr(i)) & "]")(1).Text = "my changed text " & Cstr(i)
Next
End With
'our end time...
Debug.Print Now
End Sub
(NB you cannot do it by mapping all the controls to a single XML element because then all the dropdowns will all be updated to the same value whenever you change the value of one of them.)
Apologies for any typos - I've changed the code to be more in line with what you have already and have not tested the changes.