Indentation of Error Handler in Excel VBA - excel

Question

This is a very fussy question: I am inserting an Error Handler in a For To loop in Excel VBA; I want the content of the loop indented, such that:
For i = 0 to n
On Error GoTo ErrorHandler:
'~~> code here
ErrorHandler:
'~~> code here
Resume NextLoop
NextLoop:
Next
However, Excel VBA automatically cancels indentation of Error Handlers:
For i = 0 to n
On Error GoTo ErrorHandler:
'~~> code here
ErrorHandler:
'~~> code here
Resume NextLoop
NextLoop:
Next
I have tried to unselect option "Auto Indent" in "Tools" > "Options" > "Editor" but this hasn't worked.
How can I avoid this?

Answer 1

Edit There was a careless mistake in the original code. Thank you user2426679 for giving me the opportunity to fix it.
Original post
Code that uses GoTo Label can be a nightmare to understand and get error free. The only situation I know off in which GoTo Label might be appropriate is a fatal error exit where there is no intention to return. Jumping out of an error and trying to jump back is very difficult to get right and very difficult to understand when you return to it in a few months.
Is there more than one statement in your code that can throw an error? If so, how does the error handler know which error it is handling?
I favour:
On Error Resume Next ' Suspend normal error handling
Statement that might throw an error
On Error GoTo 0 ' Restore normal error handling
If Err.Number <> 0 then
' Code to handle error
End If
The value of Err.Number and Err.Description will tell what the error is and allow to write specific error handling code.
Some argue that taking error handling out of the main code keeps the main code clean. There is some merit in this argument. If there are dozens of potential errors, the analysis can become complicated and make the normal path difficult to isolate. But, in my experience, this is very unusual. Perhaps, you have a list of files some of which might not open. There are lots of reasons why a file does open but your code can do nothing about them. All it can do is display Err.Description and move onto the next file.
New text and code
Apart from the mistake in the code there is nothing in my original post that I now consider incorrect. However, I do not think the original post was as complete as it should be.
If you search for “VBA Err.Number” you will find sites that list VBA’s error handling codes. Since these sites come and go, I will not recommend my favourite. However, I try to generate errors to see what happens. Consider this code:
Option Explicit
Sub DemoErrorHandling()
Dim ErrDesc As String
Dim ErrNum As Long
Dim FileNum As Long
Dim PathFile As Variant
FileNum = FreeFile
For Each PathFile In Array("", "X:", "C:\Program Files\Common Files\Intel\" & _
"WirelessCommon\libeay32.dll")
On Error Resume Next
Open PathFile For Input As FileNum
ErrNum = Err.Number
ErrDesc = Err.Description
Close FileNum
On Error GoTo 0
Debug.Print """" & PathFile & """ gives error:"
Debug.Print " A " & Err.Number & " " & Err.Description
Debug.Print " B " & ErrNum & " " & ErrDesc
Next
End Sub
Which, on my system, outputs:
"" gives error:
A 0
B 75 Path/File access error
"X:" gives error:
A 0
B 76 Path not found
"C:\Program Files\Common Files\Intel\WirelessCommon\libeay32.dll" gives error:
A 0
B 0
Note, as user2426679 pointed out, On Error GoTo 0has cleared Err.Number and Err.Description. Only by saving these values in variables are they available for testing. Note, attempting to open an empty file name and a non-existent disc give different errors.
My code demonstrates that you can loop trying different files until one opens successfully. You could keep asking the user for a file until one opened without an error.