Re: Visual Basic and ADA95

["Vladimir Olensky" <vladimir_olensky@yahoo.com>]

Mike Biedronski wrote in message <380CBFA4.BB241336@fmr.com>...

>Does anyone have info on how to link VB & ADA applications?  Working on
>a single client PC application and would like to use VB for the front
>end, and ADA for backend.


I would prefer to use  Delphi for front end instead of VB for
single PC application. I find Delphi much more convenient
and better  than VB in many respects.

Additional advantage is that Delphi is based on Turbo Pascal
(Borland Pascal OOP extensions) so it is much more closer
to Ada in syntax. It is rather straightforward to translate
TP to Ada and backwards.
Delphi 5 produces fast executables and has a lot of things for
low level programming. It comes with excellent Borland
database engine (BDE) and CORBA components.
There are huge number of ready to use components.
So considering all that  Delphi is much better choice than VB.

As for communicating between front  end and Ada core
system there are several options:

1. "Tight" integration.
   To build either part (Ada or front end) as DLL and call it from
 the other part of the system.  This was already mentioned
 by Ed Falis.

2. "Loose" integration:
Build both parts as separate applications and communicate
between them using sockets, named pipes, or CORBA.
Last option has  been successfully used in many applications.
Using "loose" integration both parts of the system can run
 independently on  the same or on different machines.
 Such approach may be compared with the monitor  and system
 block of the PC.   You may turn of and turn on your monitor
 but  the core system   will continue  to perform it's  functions
 regardless of that.

2.1. Use Java for front end and use sockets ("loose") or JNI ("tight")
 to communicate between core system and user interface.
 In this case your application could be designed to be portable
 across many platforms. You may use any browser
 on any PC to run you user interface to core system if user interface
 part was built as Java applet.

I think that the last approach is the best choice. It allows to combine
all the best form Ada and Java  technologies and has great future.
Please also note that some Ada compilers are able directly produce
Java byte code (Averstar Applet Magic and soon ??? GNAT).
Using last ones you can do Java part using  Ada.


Regards,
Vladimir Olensky