[AccessD] Framework book - was caption from code

(Jim Dettman)
<<There was a discussion long ago on this very point; why there were not
more frameworks available for Access . . . I see that other developers
have come up with things to solve the very same problems (PK generation,
pick lists, calendars, etc).  I'm still scratching my head as to why.>>

A fundamental barrier is the lack of an easy way to distribute true
components for use in Access. Any framework library built entirely in
Access lacks a reliable way to share objects with its clients. For
Office 2000 and later, the Office Add-In was touted by Microsoft as a
way of building components for the Office Suite. But it suffers from the
same object-sharing drawbacks as libraries, and because of its extremely
limited distribution, has generated very little interest from the Access
developer community. 

The core technical limitation centers around Access and its use of COM.
Access uses Project Compatibility for generating the GUIDs required for
identifying objects and their interfaces. Project Compatibility means
the object IDs are private to the project, and are re-generated each
time you fully-compile the project. That produces behavior noted before
in this group: when you reference the library in an MDB, and compile
them together, you can share objects, because Project Compatibility
enforces consistency between the two. But, if you open the library
separately, and save changes, the MDB referencing it will break, because
all the old object IDs have been replaced in the new library.

The way out of this dilemma is to build a Type Library, or TLB file. The
TLB is a separate file which provides a stand-alone, unchanging
definition of the objects and interfaces to be shared between the MDB
and the library. Both the MDB and library reference the TLB, and use it
when declaring shared objects. This way, the library can be updated
independently of the MDB, shared between multiple MDBs, and distributed
to third parties. The TLB is the key ingredient that enables reliable
object sharing. 

The catch is, you can't make a Type Library in Access. You would need a
copy of Visual Basic or Visual Studio to get the utilities required do
that task. Because a large number of Access developers don't have these
tools, you have not seen any significant number of distributed
frameworks built entirely in Access. 

-Ken