How to Exit a For Each Loop within a Function? - vbscript

Question

I've got the following Function that is designed to recursively read all WMI namespaces on a machine depending on the namespace that's been passed (by default the script calls for ReadWMI("root"). If a WMI namespace contains the name sms or ccm, I want to test writing to that namespace to validate writing works. If Writing to WMI fails in that function, I want to exit the For Loop and completely exit the function.
What I'm noticing is that when I exit the for or exit the function (using either Exit For or Exit Function) I go back to Next instead of exiting the function completely. This causes a number of issues where other namespaces can successfully be written to.
Function ReadWMI(strNameSpace)
Dim oWMI, colNameSpaces, objNameSpace, sFullNamespace
'ReadWMI = "True"
WMI_ReadRepository = "Healthy"
On Error Resume Next
'Verify all namespaces
Set oWMI = GetObject("winmgmts:\\" & sComputer & "\" & strNameSpace)
If Err.Number <> 0 Then
ReadWMI = "False"
WMI_ReadRepository = "Unhealthy"
oLog.WriteLine Now()& " - " & "ReadWMI(): Failed to bind to WMI namespace " & strNamespace & ". Stopping WMI Verification"
oLog.WriteLine Now()& " - " & "ReadWMI(): Error Code: " & Err.Number
'oLog.WriteLine Now()& " - " & "ReadWMI(): Error Description: " & Err.Description
Err.Clear
Exit Function
Else
oLog.WriteLine Now()& " - " & "ReadWMI(): Successfully connected to WMI namespace " & strNamespace
End If
Set colNameSpaces = oWMI.InstancesOf("__NAMESPACE")
For Each objNameSpace In colNameSpaces
sFullNamespace = LCase(strNamespace & "\" & objNamespace.Name)
If InStr(sFullNamespace,"ccm") Or InStr(sFullNamespace,"sms") > 0 Then
oLog.WriteLine Now()& " - " & "ReadWMI(): Writing to " & sFullNamespace & " WMI Namespace if WMIWriteRepository set to TRUE"
If WMIWriteRepository = True Then
If WriteWMI(sFullNamespace) = "False" Then
oLog.WriteLine Now()& " - " & "ReadWMI(): Failed to write to namespace " & sFullNamespace
WMI_ReadRepository = "Unhealthy"
'ReadWMI = "False"
Exit Function
End If
Else
oLog.WriteLine Now()& " - " & "ReadWMI(): WMIWriteRepository set to False or OS is a Server. Will not write to repository."
End If
End If
'Call VerifyWMI again to run through the next namespace
Call ReadWMI(sFullNamespace)
Next
'ReadWMI = "True"
'WMI_ReadRepository = "Healthy"
Set oWMI = Nothing
On Error Goto 0
End Function

Answer 1

If something goes wrong and you want to jump out of the recursive function call, make the return value False (uncomment the 'ReadWMI = "False" in your script).
Your last statement before the next must test if the reading of the WMI was correct, so instead of
Call ReadWMI(sFullNamespace)
use
If ReadWMI(sFullNamespace) = "False" Then
Exit For
End If
Protip: Stop using "string booleans", they are slow and errors are luring around the corner to bite you in the back ("True" <> "true" <> "Treu" <> "True "). Just use True and False. Whenever you want to output a boolean to a string, it is automatically converted to the correct string value:
MsgBox True & " / " & False
' Output: "True / False"