Setting Object Library References Dynamically possible?

Question

So I have an MS Access application originally in a 2002-2003 format. Developed on a production network image, and when the image pushed the office upgrade, it became office 2007. So this is used in a very non traditional way...reps take it with them on company laptops enter data, and it automates complex ppt presentations, and excel worksheet for them (they love it....they need it). Data is not held in this like a database repository, just long enough to produce the automation they need and it works....saves them time. So Access is limited, and in the use case, really limited since i am using it in a way it certainly wasn't intended to be used. I get that, but like I said so far, its working pretty well.....

The one bump I have run into is if someone has to use another computer for whatever reason (doesn't happen often but it got me thinking), and say they have a version of 2002-2003 access, the tool will run, but once we get to the code routines/modules for ppt & outlook, the object libraries show MISSING because working on this tool seems to automatically cause the libraries to go up to the next available version, but not down to find the version.....

so originally when I made this....it used MS PowerPoint 11.0, and MS Outlook 11.0, and then when I had to start working in 2007 it became 12.0 for both, some instances I see it bumped up to 14.0, and none of the ups are a problem, but now since I have an image with Office 2007 out, and new files version I try to give them has the libraries defaulted to 12.0 and if they run into a scenario where they would take the file on a disc and use it on a computer that has office 2003, those libraries just come up missing and it doesn't recognize the appropriate 11.0 object libraries anymore.

So finally my question....any suggesions (save the obvious and build a real app...lol...would love to....no $) to handling this? Is there code that can/will evaluate what libraries need to be set on opening the file using vba? Is that possible?

Answer 1

There is Remove Method which you could use to remove a reference, then AddFromFile Method or AddFromGuid Method to add a reference.

The AddFromFile approach was offered in answers to this recent StackOverflow question: Add references programatically However, make sure to read Tony's answer ... if you're distributing your application as an MDE, you're SOL.

Consider switching to late binding for your PowerPoint and Outlook stuff. That way you won't have to fiddle with references (no reference required for late binding). A drawback from late binding is you lose the benefit of IntelliSense during development. However, you can develop with early binding, then switch to late binding for deployment. Substitute the values where you used any named constants from the referenced library ... debug will highlight any you overlook.

A frequent counter-argument is that late binding imposes a "performance penalty". However, I've yet to encounter a use case where the "slow-down" was large enough to be noticeable by a human observer.

In any case I've been using late binding for years specifically to avoid the type of deployment issue you're struggling with now.

Edit: Here is an example which uses the Excel type library. I have it set to use early binding. To convert it to late binding, comment out the declarations under '* early binding ... , and uncomment those under '* late binding ...

Also notice the 2 lines which include the named constant, xlAutomatic.

Public Sub EarlyVsLateBinding()
    Dim strFullPath As String
    '* early binding requires reference to Excel type library *'
    Dim objExcel As Excel.Application
    Set objExcel = New Excel.Application
    Dim objBook As Excel.Workbook
    Dim objSheet As Excel.Worksheet
    '* late binding; no reference required *'
'    Dim objExcel As Object '
'    Dim objBook As Object '
'    Dim objSheet As Object '
'    Set objExcel = CreateObject("Excel.Application") '

    strFullPath = CurrentProject.Path & Chr(92) & "foo.xls"

    Set objBook = objExcel.Workbooks.Open(strFullPath)
    Set objSheet = objBook.Worksheets("bar")
    objSheet.Range("B1").Select
    With objExcel.Selection.Font
        .Name = "Arial"
        .FontStyle = "Regular"
        .Size = 10
        .ColorIndex = xlAutomatic 'named constant available with reference set '
        '.ColorIndex = -4105 'substitute xlAutomatic value so we drop reference
    End With
    objBook.Close SaveChanges:=True
    objExcel.Quit
    Set objSheet = Nothing
    Set objBook = Nothing
    Set objExcel = Nothing
End Sub