[AccessD] Framework Discussion - Dependent Objects

John W. Colby jwcolby at colbyconsulting.com
Sat Mar 13 19:43:09 CST 2004


Jim,

What I think that you are forgetting is that VFP. like .NET is a system with
true inheritance.  Access is not.  Thus with VFP or .Net you can get bogged
down with classes inheriting classes inheriting classes inheriting classes
inheriting..  And of course all that inheritance has to be "built up" as the
classes load.

Access has none of that.  Nothing inherits anything.  What a framework in
Access really provides is nothing more than objects (classes) written for a
specific purpose, to perform specific processing.  Often they are wrappers
around objects that have no classes of their own allowing us to "simulate"
in a very crude sense inheriting the object, but the "inheritance chain"
comes to a screeching halt immediately unless of course you were to write a
wrapper to a wrapper to a wrapper.  Our wrapper allows us to do nothing more
than add custom functionality to THAT wrapped object.  Of course a class can
instantiate another class to obtain encapsulated services that it needs but
that is hardly the same thing as what you are referring to.

In the end, my current framework has... 45 classes (I just went and counted
them).  Of that number, 17 are wrappers to the various controls and the
form.  The rest are "services" of one type or another - FTP, HTTP, Zip,
Unzip, Enigma, MD5, Sysvars, Timer, AuditTrail, DependentObjects etc.

Access is NOT a true OO environment.  It has objects, of which you
manipulate methods and properties, however true inheritance is virtually
nonexistent.  The issues that you refer to with VFP and .NET simply cannot
occur in Access because of that.

Believe me, given my druthers I'd take true inheritance and deal with the
speed issue that might occur.

John W. Colby
www.ColbyConsulting.com

-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com]On Behalf Of Jim Dettman
Sent: Saturday, March 13, 2004 5:38 PM
To: Access Developers discussion and problem solving
Subject: RE: [AccessD] Framework Discussion - Dependent Objects


John,

<<I have a usable framework already, in fact I am looking at my old to find
subjects for these articles.>>

  "Useable" was probably a poor choice of words on my part.  I was really
thinking in terms of features.  I slid into "useable" in the sense that by
the time you add everything that everyone might want, you've got everything
except the kitchen sink<g>.

<< Would you notice an additional 1/50th of a second for
the framework to do it's thing?>>

  I only mention it because as you get further down the road and into
composite classes, there gets to be a design decision in regards to how a
framework should be structured for what offers.  The out come of that can
have a large impact on performance.  This is one of the hot button issues
with VFP frameworks, which you know are quite a bit farther down the
framework road.  Considering that VFP is a true compile and it's an issue
there, I don't see how it could not be an issue at some point with VBA.

Jim
(315) 699-3443
jimdettman at earthlink.net






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