Other than the subject line and a few fine points, I agree with Gavin 100%.

Gavin Scott wrote:

>It's getting late, but I'll take a few random stabs at it...

Getting late?  1:18 AM *is* late...

>XML is overkill for most applications just as FEDX is overkill for
>intra-office mail.
>Most people talking about XML and how great it is don't understand it, and
>certainly haven't seen it do anything significant.

Yes, indeed.

(Snipped excellent discussion of markup languages...)

>If we already share a common
>language (English, COBOL, HTML, etc.) then I can just write up a document
in
>that language and send it to them, knowing that they will be able to makes
>sense of it since the language we agree on (and its interpretation) is well
>defined.  If there is no common language, then maybe I can use XML to make
>one.

On common language, I'll take you one further.  Those of you with teenage
children may speak the same language as your children, but somehow the
spirit of your message is still lost during the conversation.  When a man
uses the word "love", it is quite possible that a woman hears something
other than what the man thinks he's saying.  (In fact, I may have lost half
of you on that sentence...)

>So, ok, I want to communicate with someone.

In the case of Web-enabling our legacy applications, we are just going to
communicate with our internal programmers/web developers.  The only people
who have to know the MMML (MANMAN Markup Language), AML (AMISYS Markup
Language), QML (QSS Markup Language) or WML (Whatever Markup Language) is
going to be internal to your company.  This new document is in a platform
neutral format which can be used by any number of apps.  In fact, is this
not the model for Java?  One can, and some do, argue that a byte-code
interpreted programming language is a waste of time.  Cobol is must faster,
right?  If we started web-enabling our apps and hard-coded the HTML3 in our
programs, we may have to start over to provide HTML4.  Again for wireless
devices.  And so on.  The XML-based document should insulate us somewhat
from changes.  One must balance the flexibility with speed.

Now, if we are talking about communicating with folks outside our buildings,
than Gavin makes a point that needs to be made way more often.

(snip more good stuff)

>...You end up having to write a sort of
>event driven state machine to read the tags and data as they come out of
the
>XML "parser" to your program.  This isn't the sort of thing that your
>average COBOL programmer is familiar with either.

OK, I'm going to separate here just a little bit and give the Cobol coders
the benefit of the doubt.  Any COBOL programmer is used to reading flat
files and reacting to the "event" of an input variable changing.  I do agree
that walking a DOM tree will be a new concept but SAX shouldn't be a big
leap.  There is another tool too.  Someone actually came up with a way to
convert flat files to XML documents and back....

>The process of communication goes something like:
>
>Produce data -> Encode data -> Transmit data -> Decode data ->
>Understand/use data
>
>XML languages can help with the encoding and decoding of communicated
>information, but the don't do anything for the actual interpretation and
use
>of the data when it gets to its destination.  The knowledge of how to
>interpret what the data *means* has to get to the destination via some
>completely different means.

Amen.  If I hear one more person promising "seamless integration using XML",
I'm going to scream.  The XML/EDI, Oasis, and BizTalk groups only offer a
way to exchange document definitions.  I have seen no progress in the way of
application integration.  I could go on and on on this topic.  That's a post
for another day or a whitepaper on "Why EDI will never be Plug n' Play".

Erik Vistica wrote:
> Hi Gavin, I'm XML illiterate (and just might remain so) but if I
> understand what you're saying, a mag-tape with both the datafile and the
> COBOL copylib member describing the record layout would amount to the
> same thing (and easier to use too). Am I missing something?

Platform independence.  If everyone you are sharing the data has a tape
drive (same format, etc.) and distance is not an issue, go for it.  But
Gavin is right, the copylib may tell you just as much as the DTD.  Remember
how we started:  XML is just ASCII.

Mark Wonsil
4M Enterprises, Inc.