Reply-To: erik.wachtmeester@bighole.iaf.nl
Markus Wiederstein wrote in a message to All:
 MW> i would like to start a small-talk for porting clipper apps
 MW> to windows.
 MW> I know there are different ways to do this and there are
 MW> lots of tools around.
 MW> - Clip4Win
 MW> - FiveWin
 MW> - Alaska X-Base++ (OS/2 and Windows 95/NT)
 MW> - CLWINDOW
 MW> - VisualObjects (i liked the ASPEN working title)
 MW> Is there any clipperhead around who can show me
 MW> the right way .... 
I guess it depends on the kind of applications you are dealing with. Most
existing Clipper apps are menu driven / procedure driven (the user selects a
procedure from some kind of menu and doesn't return to that menu until the
procedure has finished), and I personally don't think that way of handling
things will work in an event driven environment like Windows, OS/2, X11, etc.
Even if you could port some or most of the core functions of the program, you
still have to rethink almost every part of the program in order to get the 
most
out of the GUI.
Anyway, we've decided not to port our project (a hotel property management
suite, about 150,000 lines of Clipper code), but to rewrite it from scratch 
n
Delphi. It looks like a lot of extra work, but in fact it's not that hard to
port your Clipper implementations of procedures, functions and algorithms to
Delphi's Object Pascal by hand. And you don't really rewrite it from scratch,
because the hardest part of programming (developing algorithms, database
structures and functionality) is already done for the Clipper project, so a
large part is "just" a question of recoding these things in another 
environment
(both design time and runtime) and another language. But then again, recoding
known code is a great way to become familiar with a new language (I progammed
quite a lot in Pascal in the past, but Object Pascal was new to me).
And it's a great opportunity to cut out dead, obsolete or 
not-that-well-written
code from your application! And believe me, any substantial project that has
been developing over a couple of years contains pieces of ugly code all over 
the
place... (q'n'd patches, hacks for that special compiler or library version,
things like that)
In our case the decision not to port was also based on the fact that we 
anted
to go 'client/server' in the Windows version. And to be honest, I haven't 
seen a
real client/server solution for Xbase yet. Advantage comes close, but it 
till
is far apart from Oracle, Interbase, Informix, etc., especially when stored
procedures and server-based rollback are concerned.
Regards,
Erik 
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