Re: Advice about moving to a Web-environment -- WEB400

Several folks have mentioned RPG-CGI, so I thought I'd better drop into the
conversation.  RPG-CGI has real problems.

1. There are no real tools for it.  Unless you end up coding all the HTML
formatting yourself (which is a really bad idea), then you have to rely on a
third-party package, either IBM's CGIDEV2 or one of the commercial toolkits,
to do your work for you, and none of these tools has anything like the tool
support of JavaServer Pages (JSP).  On the other hand, WDSC (which you
already own) allows you to create web applications using WYSIWYG web design
tools.

2. If you code your middleware layer in RPG, then you can't move it off of
your iSeries.  Therefore, if for performance or security reasons you decide
that your web application server should be on another machine, you are
stuck, because RPG-CGI only runs on the iSeries.

Also, there are some people on this list who complain about how hard Java
is, and that's just not true.  If you can learn how to program a subfile,
you can learn enough Java for web applications.  The problem is when you
have people who try to over-engineer the Java code.  Learning advanced
programming techniques is Java is hard.  But that's not required or even
appropriate for web application development.  The amount of Java you need
depends entirely upon you and the approach you take.  You can indeed write
an entire infrastructure in Java, but you don't have to.  Instead, you can
write a very thin layer of Java that does little more than convert between
EBCDIC and ASCII, or you can use EGL and create web applications USING NO
JAVA AT ALL, while still taking advantage of Java Server Faces.


The other language often mentioned is PHP.  I have very little experience
with the P-languages (Perl, PHP, Python), but the experience I do have leads
me to believe that they're not yet industrial strength languages.  You end
up writing a lot of little script files, and if you think learning Java is
hard, try reading someone else's PHP code.  There are lots of calls to
functions, and finding those functions in anything but the smallest
environment means a lot of text searching.  When I first did some Python
work, I remarked jokingly on a mailing list that I couldn't live without
grep (the Unix string search utility) and amazingly, I got nothing but
agreement.

Now, there may be some tools that help you program PHP better.  I don't
know, I haven't seen any.  I haven't used, for example, an integrated PHP
debugger.  But unless they integrate into WDSC that means you need separate
tool sets for developing and debugging your middleware and your business
logic.

The real thing to realize is that scripting languages are more like Basic
than RPG.  And if you're the kind of programmer who prefers Visual Basic to
RPG, you'll probably be more comfortable in a scripting language than in
Java.  PHP and especially Python allow you a lot more flexibility to "design
on the fly" and require less up-front design.  You pay for that flexibility
the same way you pay for complexity in Basic programs: extra debugging and
design time on the back end.


My .02

Joe

From: Ewout N Boter

I post this message because I would like to get some advice of other
people who have made the transition from a traditional
5250/RPG-environment to a Web/Java-environment.

At our shop, we are only developing 5250-applications. We use ILE RPG in
the way ILE was intended for, i.e. we have created a lot of procedures to
encapsulate business rules, we use service programs, activation groups,
etcetera. Thus, we have adopted some of the modern features of ILE RPG,
but we are still stuck with 5250-applications. We now want to make the
transition to GUI- and/or Web-applications, but we don't know how to
proceed. We have bought some books about using Java on the iSeries, one of
us is doing a course on WebSphere Application Server, we have some
thoughts about a Web-application we would like to build, but we are not
feeling confident enough to really get going. Therefore, I would like to
know how other shops have made the step to modernization. I think that we
might learn a lot from the experience of others who have travelled along
the way we have ahead of us. Any response would be greatly appreciated.