RE: DDS Screens To Java

Nathan asked

>Are you saying that scrolling through a
>Webfaced subfile would take 30+ seconds
>per page on a model 620?

Exactly.  Almost all of that is Websphere performance.  The 620 is marginal
on memory at 1 gig and it has no L2 cache.  The only break I get is that it
isn't CPU bound (it mostly does communications.)

>I wonder what maintenance is like after
>the initial conversion?  Do you still
>maintain the original display file?

Yes.  This is one of the slicks part of WebFacing.  Change the DDS, run that
one through the converter, export the conversion to the IFS and you're in
business.  The green screen and the Java stay in synch.

>Support both GUI and 5250?

By definition, once the DDS gets converted you're automatically supporting
DDS and GUI, and only touching the DDS.  That's the "I don't know anything
about the Web" type of operation that gets us green screen guys going.

>What if you'd like to add script to
>the generated JSP?

Don't tell the WF guys, but I modified the .jsp on the IFS after generation.
That's a maintenance hassle because you have to re-do the changes after
every export.  There is a better way if you use Code Designer.  There's a
tab there that lets you do HTML things to the DDS.  This is stored as
comments in the DDS source.  These comments are interpreted by the
conversion tool to generate the appropriate HTML.  I have NOT gone far into
this; the scripting I wanted to do was one of those "changes during a demo"
thing, and I just wanted to get something going in a second, which is
literally all it took.

>For example, to support Function Keys?

I don't know how to directly support F keys.  The browser 'owns' the
physical PC F keys.  The DDS F keys get mapped to browser buttons.

>For record formats that overlay other formats,
>do you have to change multiple JSPs?

I haven't had to.  The key to the whole thing is that RPG passes an output
buffer to WF and reads an input buffer back.  WF 'pretends' it is a 5250
device.  As long as you don't monkey with those buffers you are good to go
with the caveat that it's hard to tell what screen you're on.  In other
words, RPG does WRITE MSGSFL, WRITE FOOTER, EXFMT SFLCTL.  That's three
output buffers that go to 3 beans.  The jsps do the formatting on the screen
(mostly tables.)  If your script moves you to another HTML page you have to
be very careful to feed the correct buffers back to the RPG program that's
still waiting on the EXFMT.  If it expects a subfile full of data and you
pass back a single customer number, the RPG will die (basically a level
check.)

>Is the conversion tool a one time procedure,
>afterwhich you maintain JSPs and Beans manually?

No, the conversion would be used day-to-day by 'real' programmers who also
use Code Designer to implement their DDS source level changes.  That's the
intent anyway.  I still need to do more tinkering, which I'll do Real Soon
Now.

  --buck