RE: Is RPG dying

-----Original Message-----
From: rpg400-l-bounces@xxxxxxxxxxxx [mailto:rpg400-l-bounces@xxxxxxxxxxxx] On Behalf Of John McKay
Sent: Thursday, February 16, 2012 2:49 PM
To: RPG programming on the IBM i / System i
Subject: Re: Is RPG dying

While I regard RPG as a very efficient and cost-effective language (short learning curve, low development hours, good development visibility), I see a number of factors >which restrict its popularity.

First, unlike other languages, it is restricted to one platform. (I remember someone had a Windows PC version out in the 80's but it never caught on).

Technically, in IMHO, all languages are platform-specific. Every platform provider has its "enhancements" to a language. Even Java requires its own virtual machine (aka operating system) run on top of the hosting operating system.

Secondly, it is weak when developing user-interfaces, GUI's. RPG is essentially a server language. Given that nowadays most AS400 screens are on Windows or UNIX >operating systems, I think IBM missed a point by not making it easier to access the full memory capability of Windows and Unix for user interfaces embedded in the
RPG code. For example, instead of WORKSTN on the F specs, WNDWGUI or UNIXGUI. Mind you, if some smart person could write a routine and link it as a SPECIAL
device ... I concede that you can use HTML on the green screen, but I have never seen it used effectively

Now this one I have to smile at and agree up to a point. I asked John Sears once when IBM was going to develop a GUI for the AS/400. As memory serves he said they tried it with X-Windows but had run into memory handling difficulties with the AS/400's single level storage model. This was before Windows was even released. DOS was the rage.

So, IBM left the user interface development decision up to the customer and third parties. They chose to continue providing a 5250 interface via a server again leaving it up to other interested parties to develop some other interface server.

Yet, technically, Client Access is a GUI interface. It's just that within the body of the window you are constrained by the TN5250 data stream. The client (CA) converses with the telnet server. The server doesn't handle any of the GUI stuff it is all done by Client Access.

Some companies provided "Modernization" strategies and some have been successful. Not all these companies developed a product where you develop a GUI and just connect it to any operating system. Websphere seems to be an attempt by IBM to do just this. At least Eclipse in its various incarnations has a consistent interface.

Open Access RPG does open (no pun intended) the door for in-house or third parties to develop alternatives to TN5250. Some are taking up the challenge.

OAR provides so many possibilities it makes my head swim. Forget about GUI for an instant and imagine what could be done to make seemingly separate OSs appear to be a single homogeneous one.

Thirdly, as another contributor has already stated, RPG is a procedural language, as opposed to OO. OO and UML are the current and future trends in software >development.

It all becomes procedural at some level. That an object accesses a database somehow doesn't mean the database access is OO. SQL is procedural. You can argue that JDBC is OO but it still gets down to SQL statements being run one after another. At least on the i it does.

Adapting OO design techniques for RPG is quite helpful. Reuse really pops out at you.

RPG is not dying but it is becoming a niche language. One thing we learnt from Y2K work was the amount of legacy code that exists in the background. This will exist >and work well into the future., but also will be changed project by project slowly over the years to come.

Conquest by attrition or, evolution over revolution. I agree.


Gary Monnier