Re: What do I use?

On Apr 15, 2007, at 10:18 AM, Joe Pluta wrote:

From: Paul Raulerson

The comparison in terms of "thick" client is something on the order
of Visual Age Developer, which isn't something most RPG programmers
are going to come in contact with. This is pretty much were EGL
descended from. It can generate a full fledged application, including
all the UI interfaces, and runs through CICS. It's getting a bit long
in the tooth, and Rational is now grafted on to it with an Eclipse
front end. I used VA/GEN pretty much in the late 90's and very early
part of this decade.

Uh... you haven't kept up with the tool at all. It's now a fully functional
Java-based generation tool. It is actually the focus of a significant
portion of IBM's development strategy, and the enhancements you'll see over
the next few years will be quite impressive.

One thing: to call EGL long in the tooth and then promote Citrix, which was
created back around 1989 or 1990, is pretty funny :).

It doesn't even exist anymore Joe - it is now part of the Rational Suite. It has *always* generated Java or COBOL code, even back in the days when it was knows as CSP. ;)

Heck, I don't complain about anything just because it is old - I program in Assembler on a regular basis, as well as RPG and COBOL and C. But IBM often will get on the train for the "latest and greatest" technology, and then abandon it not too many years down the road. Rather they will for this kind of technology.

Citrix, or the other application servers that replace it are really *really* good at what they do now.

It doesn't take much, if any, longer to get someone able to do the
same with VARPG, or indeed, even with Visual Basic or any of the
other applications languages out there.

There's a huge difference between page-oriented and event-driven screens.
It's very difficult to teach someone the way to properly design a
multi-panel, widget-rich environment. You can teach someone how to do
thick-client 5250 panels, but to teach them to build the rich, interactive
graphic applications you're talking about takes a long, long, long time.

A standalone GUI app is far closer to event driven than it is to a green screen of course, while web screens are much closer to green screens. The fact that they use shadow pages and JSP technology (and AJAX and all the real new stuff too) to make web applications more like a standard GUI application is also telling.

You are stating that it takes someone a "long, long, longm time" to learn to build a proper GUI application - and stating it like a fact graven in stone. It is nothing of the sort.

Sit someone down and you can teach them to write a standalone Visual Basic application to do something useful in about a day. It takes a day to just to cover the multiple technologies needed to write a web application, much less get anyone started writing one. The VB application can be written on a standalone PC, and deployed from the same PC with a high level of confidence that users will be able to install and use it.

A web application requires a pretty extensive infrastructure be in place and setup before you can successfully deploy.

There are toolkits and languages similar to Visual Basic on Macintosh and UNIX platforms as well. All at approximately the same level of difficulty as teaching Visual Basic on a Windows machines.

And deployment using an application server is a snap too- generally not much more than installing the program. Yes, it requires some infrastructure setup and maintenance, even in a tiny deployment, but you can do tiny deployments too.

Few programmers of ANY ilk (and I consider RPG programmers to be some of the
strongest programmers around) find it easy to create intuitive user
interfaces of the level of Microsoft desktop applications. That's why
there's really only one major Open Source competitor.

Huh - the same is true of web applications by the way.

I disagree with your reason why there is no successful challenge to Office by the way; the level of difficulty is not the reason - it is the lack of market that keeps it from happening. If it is worth doing, it is worth getting paid for, and MS has that market locked up. The products are good. The interface - well - the interface is not all that good, especially in the 2007 versions.

The real alternative is application servers - like Citrix or NX.
Deployment takes even less time than the typical deployment time for
a WebSphere application, and screen display is far less dependent
upon network and local processing resources.

Nah. I don't see X-Windows style interfaces flourishing. Too low- level.
You're going to need a standardized widget presentation language patterned
after HTML (something lie XUL) so that the presentation side can format the
stream as it needs.

Ah - you have it already, in things like TCL, Ruby, and other applications. And the idea of widgets came from X11 in the first place. ;) But seriously, HTML is too clunky. A Visual Basic like interface for the web will be what eventually wins. Rational Web Dev is close, very close, but way too overloaded with complexity and piggy performance. It is also too darn expensive to put on a million desktops or so, though IBM would be glad to provide a deep discount there.

Yes, I am aware of the Microsoft web development tools - ASP has problems just like the IBM Java based equivalents.

They will get there eventually, but I really expect what we will see is a thin client Visual Basic at that point. Probably running on top of X or Aqua. :)

And as far as I can tell, the licensing for Citrix is horrendous. How in
the world are you going to support 10,000 users for Citrix? Does everyone
get a CAL? Or do you just run out of CALs during your peak business times?

Yep - Citrix licensing is a PITA, second only to Microsoft licensing.

So use 2X, or Linux, or NX, or some combination. All of those can be obtained for free if you want to support yourself, or at a very reasonable cost from SuSE or Redhat or other places.

It has everything to do with sluggish from our perspective. Can you
send me some links or additional detail on web apps that fast offline
please? (P a u l [at] Raulersons dot com)
We typically cannot even get a browser or Java application to refresh
a display that quickly. That kind of speed would be a big factor in
our evaluations. And that is using the internal gigabit network - lag
and queuing delay over the WAN make it miserable for complex screens.

What's so hard? Write a simple servlet that updates a counter and outputs
it to a JSP. Have the JSP show the counter and a button. When the button
is hit, go back to the servlet.

I rather thought you were talking about a real application, the kinds that have to hit a backend datasource, perform significant edits on the data, and redisplay screens fairly quickly. Hopefully doing things like telling the user what went wrong. You can get subsecond response out of a Palm M100 with the kind of application you describe.

I have not seen a real heavy duty transaction processing application on the web with the kinds of response time you indicate you get - especially on applications distributed over the WAN to multiple remote geographic locations.

I would be quite willing to look at one if you know where one is.

Create a JavaScript function to check for the page down key. When it senses
the page down key, it presses the button. Start the application, hold down
the page down key. Unless you have some serious latency issues, that page
should update the counter many times a second.

I do this with my PSC product. I web-enable subfiles and even over a WAN we
get sub-second response time.

That I would really like to see - especially with some rather complex screens that require updating based upon processing of entered data.

Yours,
-Paul

Joe


--
This is the RPG programming on the AS400 / iSeries (RPG400-L) mailing list
To post a message email: RPG400-L@xxxxxxxxxxxx
To subscribe, unsubscribe, or change list options,
visit: http://lists.midrange.com/mailman/listinfo/rpg400-l
or email: RPG400-L-request@xxxxxxxxxxxx
Before posting, please take a moment to review the archives
at http://archive.midrange.com/rpg400-l.