[AccessD] Access 2010 or later - storing and referencing code in libraries

[John Colby]

BTW I ran across the "helper function" thing decades ago but never used it
because I never had to.  I just used the "Export, Modify, Import" trick.

On Thu, Jun 17, 2021 at 12:50 PM Jim Dettman via AccessD <
accessd at databaseadvisors.com> wrote:

> John,
>
>  Don't know the answer to this right off, but the docs/comments I find all
> say that the VB_Creatable attribute is ignored with VBA.  I know you said
> you've done this in the past, but all these docs/comments are more recent
> and I wonder if a change might have been made, or if something else that
> was
> done cut the ability to do that off.
>
>  But I did find this, which I think you'll find interesting and may be of
> help:
>
> How to use a class (object) from outside of the VBA project in which it is
> declared
>
>
> https://docs.microsoft.com/en-us/previous-versions/office/troubleshoot/offic
> e-developer/set-up-vb-project-using-class
> <https://docs.microsoft.com/en-us/previous-versions/office/troubleshoot/office-developer/set-up-vb-project-using-class>
>
>   Using a helper function, it shows how to instantiate a class in another
> project.
>
> Jim.
>
> -----Original Message-----
> From: AccessD On Behalf Of John Colby
> Sent: Thursday, June 17, 2021 12:16 PM
> To: Access Developers discussion and problem solving
> <accessd at databaseadvisors.com>
> Subject: [AccessD] Access 2010 or later - storing and referencing code in
> libraries
>
> I need assistance creating a library file, using Access 2010, which
> contains CREATABLE classes.
>
> If you export a class made in Access 2010 using the 2007 file format, in
> the header it will have a set of properties looking like this:
>
> VERSION 1.0 CLASS
> BEGIN
>   MultiUse = -1  'True
> END
> Attribute VB_Name = "dclsFrm"
> Attribute VB_GlobalNameSpace = False
> Attribute VB_Creatable = False
> Attribute VB_PredeclaredId = False
> Attribute VB_Exposed = True
> Option Compare Database
> Option Explicit
>
> Back in the day, I would change vb_Creatable as follows:
>
>   Attribute VB_Creatable = True
>
> What this does is allows the class to be stored in an MDS file, then
> reference the MDA and use the class from there.  The vb_Creatable
> propert specifically allows the class to be instantiated using "Dim MyCls
> as new clsXYZ"
>
> Without the file having the VB_Creatable = true, the class can be seen
> but cannot be instantiated.
>
> So... I export the class, I edit the file in a text editor setting
> vb_Creatable = true, I reimport it back into the file.  If I export it back
> out, the property has been changed back to VB_Creatable=False.
>
> And of course, if I reference the library, and try to instantiate the class
> it fails to compile.
>
> Understand that I have the exact same code in an old MDA file.  If I open
> that mda file WITH Access 2010 and export the class to a text file the
> vb_Creatable is in fact True.
>
> I am utterly failing to create an MDA file in 2007 file format which allows
> me to do this thing.  I am unable to even truly create an MDA file.  I can
> call it .MDA but the lock file will be .Accdb.
>
> I can create an Accda file but it too fails to retain the vb_Creatable =
> true, and any file stored in said file will not instantiate.
>
> This is really basic stuff.  I used it for a decade to store my framework
> and dozens of classes in C2DbFramework, reference the mda file and used "as
> new" syntax.  I no longer can do this.I can't find any reference out on
> google to doing this.  Lots of stuff about these hidden properties of
> classes, most of it wrong, none of it discussing using classes from a
> library file.
>
> Help me Obi Wan...  Is there an Obi Wan left amongst us?
>
> --
> John W. Colby
> Colby Consulting
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-- 
John W. Colby
Colby Consulting