RE: When To Use Schemas (Was RE: infinite depth to namespaces)

["Bullard, Claude L (Len)" <clbullar@ingr.com>]

I can agree with that.  Teach well-formed first.  The  
issues start because of the different backgrounds.  The 
comment from a VP here who has preached "declarative 
only" for years when shown XML Schemas was "Why bother? 
They don't do enough."  The relational expert reduced 
all his files to two level trees with tablenames and 
column elements then wanted to know how to make sure 
all the characters made it into the text content, say, 
text elements that contain ALL whitespace.
  
As soon as one is out of well-formed, the fight 
starts in earnest.

Oddly enough, the writers look at the DTD or schema 
and say, "a validator; good" and go right to using 
it.   

All of the above look at XSLT and say, "too hard!!" 
Those that get past that say, "hmmm... powerful stuff" 
except for the PERL and sed hackers who say, "too 
verbose" and "did this already and it was easier".

I'd say, honestly and sincerely, that complexity  
scales to the ambitions of the user.  I see it in 
animation where one accepts it is demanding craft 
or declares it "uncompelling" because it can't be 
done by a teenager who just learned HTML. 
It's easy to make an orbiting solar system with 
some spheres, a background, a few interpolators 
and some material nodes although one might have 
to think about how to nest the coordinate systems. 
On the other hand, you can't create Shrek without 
starting with triangles and code and hiring 
300 highly paid specialists for three years.

Len 
http://www.mp3.com/LenBullard

Ekam sat.h, Vipraah bahudhaa vadanti.
Daamyata. Datta. Dayadhvam.h


-----Original Message-----
From: John E. Simpson [mailto:simpson@polaris.net]
Sent: Sunday, September 02, 2001 6:53 PM
To: xml-dev@lists.xml.org
Subject: Re: When To Use Schemas (Was RE: infinite depth to namespaces)


At 09:26 AM 09/03/2001 +1000, Marcus Carr wrote:
>...Given the question though (I'm designing my own simple XML
>vocabulary, but I don't understand either DTDs or XML Schema. What can I
>do?), I don't think that validation necessarily even enters the
>equation. A DTD is a very useful aid to designing and maintaining an XML
>vocabulary, regardless of whether it is subsequently used for
>validation. Perhaps John should have asked himself a slightly different
>question...:-)

:)  In my own defense, what I was really going on about there wasn't 
validation per se, the general usefulness of DTDs/schemata, and so on. It 
was the relentless focus on them -- as though it's impossible to do 
anything at all useful without them. ("The focus on DTDs and XML Schema as 
the hallmark of so-called real XML has done more to damage XML's widespread 
use and popularity [etc.]...") They're extremely useful tools once you've 
got the basics nailed down, but can be a stumbling block en route to that 
point.

Not wanting to drift off into pedagogical theory or anything, but it's 
generally a question of deductive vs. inductive learning. Teach someone 
well-formed first, and teaching them valid later will be a piece of cake 
(especially when they ask the question themselves: "How do I assert that 
structure/datatype X is *required*?"). Make them learn valid first and 
you'll postpone their doing *anything*. It's like forcing them to attend 
the first half-dozen sessions of a course in Java or C++ before showing 
them the "Hello world!" exercise.

Mostly I just wanted a question that would trigger some righteous 
indignation in me... even if the hypothetical newbie didn't get her actual 
question answered in the process!

=======================================================================
John E. Simpson        | "I saw a sign: 'Rest Area 25 Miles'. That's
http://www.flixml.org  | pretty big. Some people must be really tired."
XML Q&A: www.xml.com   | (Steven Wright)


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