Re: "Webulating" RPG

[David Duerr <dduerr@xxxxxxxxxxxxx>]

Having gone through the learning curve of OO concepts over the past year,  I 
think
many RPG shops will find the transition to OO painful for a one main reason.
Having come from a non-AS/400 background with a heavy emphasis on design and
modeling tools, it has been my experience that design skills and the use of 
modern
design and modeling tools are somewhat lacking in the many AS/400 shops.

The success of a project using an object oriented language is completely 
dependent
on the upfront design and modeling work that must be done prior to writing one
line of code.  Many RPG programmers code first and ask questions later.  This
approach will simply not work with an OO language.

Before beginning a project written in an object-oriented language, the first 
step
should be the development of a complete  model of the system you are developing,
including class diagrams, use case diagrams, data models, and other object
oriented modeling diagrams.  We have been using the tool Rational Rose to model
our systems in UML for approximately 9 months and it has revolutionized our
development--even projects written in RPG ILE.  Is requires some additional
methodology to apply UML models to construction in RPG ILE but it is easily
doable.

Also, we have been using the data modeling tool ERwin for years.  We do 
absolutely
no database design in DDS.  Designing a database with a data modeling tool is
infinitely more efficient than pounding out DDS and adding constraints to files
one by one. Also, having experience with another PC based modeling tool was
helpful in learning Rational Rose, so I would recommend to any AS/400 shop to at
least investigate the use of a data modeling tool, which are relatively easy to
learn compared to OO modeling tools,  that supports reverse and forward
engineering of DBS/400 databases.

My recommendation to any RPG shop that is planning a transition to an object
oriented language should invest in an OO modeling tool to do their design work
immediately while continuing to code in RPG ILE.  This will teach two very
important concepts, system design and modeling, and OO concepts themselves.
Without these skills and knowledge under your belt, learning an OO language will
be a waste of time.  Actually, as many people has said Java itself is very easy 
to
learn.  But OO requires a completely different approach to software development.
I would recommend to not even begin learning an OO language until you have 
become
somewhat proficient in an OO modeling tools.  It will reduce your learning curve
by months, if not years.

Jon Paris wrote:

> >> "I disagree Jon. I think it is easier to just dive in to the OO concepts
> and "learn to swim". However, I agree that the gradual migration across
> the ILE facilities smooths out the "down time" over a longer period by
> allowing developers to still remain productive while picking up new
> concepts. This should be easier for the stock holders to swallow." <<
>
> I think we agree in practical terms Chris, as you note in the second part of
> your note, those faced with a river full of aligators may find it less painful
> to learn to swim in the backyard pool before diving in completely.  If you can
> spare the 3 to 6 months it takes most people to unlearn all they know about
> designing and coding in a procedural world, then "diving in" works fine.  My
> experience has been that most people don't have that sort of time.  Of course
> some are lucky and just tended to design in an OO fashion anyway (even if they
> didn't know that's what they were doing!)
>
> Jon Paris - AS/400 AD Market Support - paris@ca.ibm.com
> Phone: (416) 448-4019   -   Fax: (416) 448-4414
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