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RE: Quiz: XML flexibility

• To: "'Razvan MIHAIU'" <mihaiu@m...>
• Subject: RE: Quiz: XML flexibility
• From: "Michael Kay" <mike@s...>
• Date: Sun, 27 Feb 2005 21:09:03 -0000
• Cc: <xml-dev@l...>
• In-reply-to: <20050227223204.dvdbaizmj5twgss0@w...>
• Thread-index: AcUdDEoaTLlX8hAcSHO5va9VFF5qXAAAhzfQ

>     What about flexibility ? I am more interested in what you 
> have to say about that.
>

Yes, but that takes time. I spent three years of my life trying to come up
with ways of measuring flexibility in IT systems (we called it "potential
for change") so that we could build business cases for investing in it: and
I'm not sure we achieved much.

As you say, using XML already gives you a lot of flexibility and that's why
people use it. It's also why people adopted relational databases, high-level
programming languages, you name it...

A messaging backbone with XSLT at its heart also gives you flexibility
because it means that you can change message formats in a
backwards-incompatible way provided the new format is transformable to the
old.

Validation using XML Schema or DTDs gives you flexibility because the more
you know about the assumptions that applications are making about the data
they receive, the easier it is to identify the impact of changing the rules.

One could go on and on... Nearly everything we do in the name of good
software engineering is investment in potential for change, and in nearly
all cases the benefits are unquantifiable. It's the only -ility we don't
know how to measure, and it's the most important one of all.

Michael Kay
http://www.saxonica.com/ 
> 
> 
> 
> Regards,
> Razvan
> 
> 
> >Michael Kay
> >http://www.saxonica.com/
> >
> >
> >
> >>-----Original Message-----
> >>From: Razvan MIHAIU [mailto:mihaiu@m...]
> >>Sent: 27 February 2005 20:00
> >>To: xml-dev@l...
> >>Subject:  Quiz: XML flexibility
> >>
> >>
> >>Hi,
> >>
> >>
> >>
> >>
> >>	In an XML quiz I found the following question:
> >>
> >>A company wants to develop an EDI system, which will help it
> >>to integrate with
> >>its various trading partners (suppliers and clients). Their
> >>previous attempt
> >>failed, as it required a unique implementation for each pair
> >>of trading
> >>partners. Now they want to explore the capabilities of XML to
> >>make this system
> >>efficient.
> >>
> >>The company wants to keep the structure of XML documents
> >>flexible and open to
> >>future changes. Which of the following is most likely 
> implied by this
> >>requirement ?
> >>
> >>A. XML Schema;
> >>B. mixed content model;
> >>C. XSL stylesheets;
> >>D. validating parser;
> >>
> >>Correct answer: B
> >>My choice: A
> >>
> >>
> >>	Isn't this a dumb question ? I mean if you choose A you
> >>can certainly use mixed
> >>content model with XML Schema, so answer A and B are not exclusive.
> >>
> >>	What I am really trying to understand is "what is
> >>flexibility" ? In any XML
> >>document you can add elements and attributes at will if you 
> update the
> >>associated schema. Old applications would just ignore the new
> >>elements and
> >>attributes, so "flexibility" is build-in into XML. So, what
> >>are you doing when
> >>you want to design a flexible XML document ?
> >>
> >>	Can somebody give me an example of an XML document that
> >>is *not* flexible as
> >>opposed to one that it is ?
> >>
> >>
> >>
> >>
> >>
> >>Regards,
> >>Razvan
> >>
> >>
> >>www.mihaiu.name
> >>
> >>
> >>
> >>-----------------------------------------------------------------
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> >>
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> >>
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> >>
> >>
> >
> >
> >
> >
> >
> 
> 
> 
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  • Re: Quiz: XML flexibility
    • From: Razvan MIHAIU <mihaiu@m...>

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