Re: IBM i "Open I/O" Architecture

Hans,

Regarding Open I/O encouraging programmers to embed user interface, database, and business logic together, I can see your point, to a degree. Like with traditional design patterns, it would be a trivial matter to read from a database file and write to an Open I/O file - and visa versa.

On the other hand, it would't take much discipline to separate your Open I/O files into one service program, and your database files into another, and use exported data structures to link both together, so that related logic is separate too. Hopefully, we've learned enough from the past to have some self-motivated discipline. We don't need overbearing language constraints to enforce good design.

Also, it would be really good design to have "generic" Open I/O handlers encapsulate parsing and formatting logic according to the type of device that the RPG program might be interfacing with.

-Nathan.




----- Original Message ----
From: Hans Boldt <hans@xxxxxxxxxx>
To: midrange-l@xxxxxxxxxxxx
Sent: Thu, October 22, 2009 11:17:44 AM
Subject: Re: IBM i "Open I/O" Architecture

Jon: You've accused me of negativity in the recent past. But reading this
doesn't help make me feel more optimistic about RPG's future.

I'm sure you can't comment in any great detail since I'm sure you're under
NDA. But the rest of us are left to speculate on what "Open I/O" means for
RPG. The suggestion that this is all within RPG dampens my own over-active
imagination. This could have real potential with the right support from
the O/S, in my opinion.

The way I see it, if people expect this to be some sort of "magic bullet",
I suspect they will be disappointed. Here's one scenario I envision for
web apps: I see Open I/O as a means of abstracting the presentation layer
from the business logic. Rather than outputting raw HTML, you pass buffers
of data via an I/O-like interface to the program that formats the data.
This doesn't really make things any easier. It's just a different way to
structure the application.

My thoughts are still wavering back and forth on this, but I can't help
feeling this "Open I/O" is a bad direction for RPG. Look, for decades,
we've been telling people to restructure their apps to separate I/O from
business logic to prepare for new forms of UI. (You know, the old MVC
model.) This kind of thing may well encourage the embedding of user
interface logic with business logic.

Will this have any impact on the ~70% of shops that haven't even adopted
procedures? The current hype may get some of them to learn a bit more,
which would be good. Will it be enough to encourage them to embrace more
current RPG programming techniques? I suspect most of these programmers
will be doing RPG III programming until the end of their careers.

Cheers! Hans