Re: Enlightenment via avoiding the T-word

[Ronald Bourret <rpbourret@rpbourret.com>]

"Henry S. Thompson" wrote:
> 
> Ronald Bourret <rpbourret@rpbourret.com> writes:
> > >From my reading of the schema spec, this is what a validator does. My
> > point is that it would be nice if the PSVI was clearly factored so I
> > could write a processor to just add type information without performing
> > validation. This would be much cheaper and would be useful in
> > applications where I trusted the source of my documents.
> 
> What factoring of the PSVI would you like that isn't already there
> implicitly?  The W3C XML Schema REC defines a number of properties for
> use by conformant schema-validators.  It is already open to you to
> make provide a subset of those properties of your own choosing in the
> output of some non-validating processor that you write.  If a
> downstream app needs only your properties, then it can run either on
> top of a conformant schema-validator, or on top of your processor.

It is true that I can take what I want from the infoset, but that's not
a good way to build mass-market software. Assuming one group of people
builds processors and another group of people build
processor-independent applications on top of those processors, the
application writers' job is made much easier by factoring.

This is because factoring means the application knows it can expect a
certain level of functionality, rather than continually having to ask,
"Do you support this?", which is the case with a continuum of
functionality. The DOM and ODBC drivers factor things this way to quite
good effect.

Without looking at every single PSVI contribution, a quick scan of
section C.2 might break them into the following sets:

1) Typing:
Attribute Declaration
Element Declaration

2) Defaults:
Attribute Default Value
Element Default Value

3) Validation:
Assessement Outcome (Attribute)
Validation Failure (Attribute)
Attribute Validated by Type
Validation Failure (Complex Type)
Validation Failure (Element)
Element Validated by Type
Assessment Outcome (Element)
Validated with Notation
Validation Failure (Simple Type)

4) Cross-referencing:
Identity-constraint Table
ID/IDREF Table

5) Schema Information
Schema Information

-- 
Ronald Bourret
XML, Databases, and Schemas
http://www.rpbourret.com
Speaker, Geek Cruises' XML Excursion '02