Re: Application modernization - any experieence

[pluta@xxxxxxxxxxxxxxxxxx]

Hey all,

I have a vell constructed big ile rpg application. The logic and the
presentation are seperated  .

My goal is to use java to modernize the application with the following
principles:

1. Maximum reuse of current logic is a must.(budget :))
2. The presentation layer should match the current
   display files BUT only with items not with behaviour. (Use the same
fields on the screen but with "field mode" and not block mode).
3. Can be done in stages. That is, on first stage can we change some
presentation and use current "green screens" for other parts(i know is
sounds weird..).
4. Since the logic is RPG based portability is not a requirment.
5. Should be ready for future distributed object technology ??

Where do i start from ? i read the papers describing several pardigms
but i'll be glad to get some reponses from people with the same
problem.

TIA for any input on this issue.
---------

Shahar, this is exactly what I taught when I was in Israel with you, with the
exception of the "field mode" vs. "block mode" issue.  First, what exactly do
you mean by field mode, and why is it important?  Even in block mode, you can
write field-level validation routines by simply subclassing the text fields used
in JbuiEntryField.  But if you're looking to do validation against the host on a
field-by-field basis, then I think your design approach is wrong.  Let's say
there are 20 fields to be edited, and some have relationships to 2 or 3 others.
You would have to code a server for each of those fields and relationships.
Instead, with block mode you edit the entire screen at once.  Block mode is MUCH
less network-intensive.

And as I said, other than that, you've basically laid out step by step the
redeployment model I spoke of when I was in Tel Aviv, except that since then
I've begun to look at WebSphere as the Internet graphical interface.


Joe


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