Issues in Error handling sub in VB Script - vbscript

Question

I have written an error handling sub in my vb script
errorNumber = DoAllWork
Sub ErrorHandling (Number, Description, i)
If Number <> 0 Then
WriteLogFileLine logfile, "Error No : " & Number & " - " & Description & " has occurred !"
Else
WriteLogFileLine logfile, "Success copying files as Err.Number : " & Err.Number & "Total " & i & " files were copied ! " & vbcrlf
End If
Err.Clear
End Sub
And I am calling it in my vb script like this
Function DoAllWork
On Error Resume Next
Err.Clear
Do Until CopyFiles.AtEndOfStream
line = CopyFiles.ReadLine
For Each line In CopyFiles
If objFSO.GetFolder(line).Files.Count <> 0 then
WriteLogFileLine logfile, "Copying files FromLocation " & Chr(34) & line & Chr(34) & " to ToLocation " & Chr(34) & ToLocation & Chr(34)
Else
WriteLogFileLine logfile, "No files present in the folder " & Chr(34) & line & Chr(34) & vbcrlf
End if
i=0
For Each File In objFSO.GetFolder(line).Files
objFSO.GetFile(File).Copy ToLocation & "\" & objFSO.GetFileName(File),True
i=i+1
Next
ErrorHandling Err.Number, Err.Description, i
Next
Loop
End Function
Now the log file which is getting created has this error messages logged in it even though the files has got copied successfully. Can someone please suggest what is wrong with this error handling technique ??
2015-12-15 15:03:47 - Copying files FromLocation "\\srv10219\archive\Article\20151116_073104" to ToLocation "C:\Users\TEMPPAHIR\LearnVB\ICCdata\Article"
2015-12-15 15:03:47 - Error No : 438 - Object doesn't support this property or method has occurred !
when I place this error handling directly after the File.copy statement, it gives me such log..
2015-12-15 16:31:55 - Error No : 438 - Object doesn't support this property or method has occurred !
2015-12-15 16:31:55 - Success copying files as Err.Number : 0
2015-12-15 16:31:55 - Total 2 files were copied !
that means for the first file which is being copied it throws an error and for the second one it gives success even though both the files has been copied successfully

Answer 1

I implemented this to do pretty much what you asked. What the script needed to do was take a folder and its contents that was dropped into a directory, and then copy the contents to a new folder formatted correctly where there was a poller that picked up the files and entered them in our system. I needed the script to quit on any error, especially for the last thing to do. That was to delete the folder from the source directory, but I had to make sure it got copied correctly. (You could clear the error and continue as well.)
So after each important line like a folder create or a file copy I did this check. This worked for me to do error handling. Passing the Err object itself is the best way to go.
Set FolderCreate = FSO.CreateFolder(PreStagingDirectory + "\" + FolderCreateName)
ReportErrors Err,"Error creating folder: " + PreStagingDirectory + "\" + FolderCreateName
FSO.CopyFile objFile.Path, FolderCreate.Path + "\", true
ReportErrors Err,"Error copying file: " + objFile.Path + " to location: " + FolderCreate.Path
Sub ReportErrors(ErrorObject, strExtraInformation)
'This will log any errors if they happen and the script will then quit
If ErrorObject.Number <> 0 Then
OutPutFile.WriteLine(DateTimeString + " Error Number: " & ErrorObject.Number)
OutPutFile.WriteLine(DateTimeString + " Error (Hex): " & Hex(ErrorObject.Number))
OutPutFile.WriteLine(DateTimeString + " Source: " & ErrorObject.Source)
OutPutFile.WriteLine(DateTimeString + " Description: " & ErrorObject.Description)
OutPutFile.WriteLine(DateTimeString + " Other Information: " + strExtraInformation)
OutPutFile.WriteLine(DateTimeString + " Script is quitting due to the Error Condition.")
wscript.quit
End If
End Sub
I have also done code like this. In this case I needed to catch if null was returned from a SQL query to the database. If null was returned and I try to cast the value, it caused an error.
To answer the question of should you check for errors in a sub and clear them, or check for errors all through your script really depends what you need to accomplish.
First I have to say error handling in vbscipt just sucks. Using 'On Error Resume Next', is absolutely needed but be careful where you place it. I found it is not best to place it in main, at the top, just within each function. Most important is to remember the scope, if you put it in a function, you catch the error there, and can handle it. If you only have it at as the first line of your script, you can only handle an error in main. It is needed in main, sometimes.
Also to debug any vbscript, comment out any call to that, or you will never know the problem.
ExecutionString = "select Sum(cast(Frame_Count as int)) from Sop_Instance_T"
Set objRecordSet = objConnection.Execute(ExecutionString)
TotalFrames = cdbl(objRecordSet(0))
'In case null is returned catch the exception
'that happens on the above line
If Err.Number <> 0 Then
TotalFrames = 0
Err.Clear ()
End If