Update LibFileTools.bas

[smartini87]

Added cancel handler in case the user cancels the operation while selecting file(s) in Sub "BrowseForFiles".

[smartini87]

The collection now returns "nothing" when user cancels the operation. Otherwise the users gets an error because the function wouldn't return a Collection as expected.

[cristianbuse]

Hi @smartini87 ,

The current method returns an Collection with zero items if the user cancels.

The line If .Show = actionButton Then specifically checks if the user cancelled and the If statement is only entered if the user did not cancel. However, because the Set BrowseForFiles = New Collection line is immediately before the If statement, then the function never returns Nothing. Instead it will always return an instantiated collection with either zero items (user cancelled) or one/multiple files based on the allowMultiFiles parameter.

I had the option to choose of these 2 options: 1) to return Nothing if the user cancelled, which is what you are proposing 2) to return a zero-item collection if the user cancelled, which is what I went for

At first glance, you might wonder why I did not return Nothing because it's the obvious choice. Well, since this is a general-purpose library, I wanted something that minimizes the risk of runtime errors and I wanted to give more flexibility to the potential user.

Consider the following snippet:

With BrowseForFiles(initialPath:=previousPath _
                  , dialogTitle:="Choose Test File" _
                  , filterDesc:="Excel Files" _
                  , filterList:="*.xlsx;*.xlsm;*.xlsb" _
                  , allowMultiFiles:=False)
    If .Count = 0 Then Exit Function
    path_ = .Item(1)
End With

With your change, the above would become:

Dim coll As Collection
Set coll = BrowseForFiles(initialPath:=previousPath _
                        , dialogTitle:="Choose Test File" _
                        , filterDesc:="Excel Files" _
                        , filterList:="*.xlsx;*.xlsm;*.xlsb" _
                        , allowMultiFiles:=False)
If coll Is Nothing Then Exit Function
path_ = coll.Item(1)

As you can see we cannot use a With construct because within the construct we cannot check for Nothing. It would be nice if the Collection class had a method like .Self or .Me or .This but unfortunately it does not.

So, I will keep the current form of the method. Thank you for your feedback!