Re: Schemas in XSLT 2.0 (Was: Re: [xsl] keys and idrefs - XSLT2 request?)

[Jeni Tennison <jeni@xxxxxxxxxxxxxxxx>]

I agree 100% that it should be possible to (a) have XSLT processors
that only support the built-in simple types from XML Schema and (b)
cast values from instance documents that don't have any schema
associated with them to XML Schema data types to take advantage of the
built-in functions/operators on those data types.

I also agree that for those of us who've grown used to using XSLT
without XML Schema, the addition of XML Schema support is, if not
quite the least of our concerns, pretty low down there.

However, in my opinion, 'normal' XSLT authors expect the hard work to
be done behind the scenes. They expect that if an instance document
points to a schema and the schema declares an attribute default then
that attribute default will be available to them in a stylesheet. They
expect that declaring that an element holds a date in a schema will
allow them to manipulate that element's value like a date in a
stylesheet. XML, XML Schema and XSLT should all just work together,
intuitively.

If they don't work together in an intuitive way, then developers will
use something that does (e.g. DOM, a proprietary interface, or even
XQuery[!]) to access and construct XML instead. Even if XPath 2.0
*doesn't* include access to defaults and type information, you can be
damn sure that MSXML will, and we'll be fighting the WD-xsl vs. XSLT
battle all over again when it comes to XPath 3.0 (actually we'll be
lucky to avoid an MSXML4 vs XPath 2.0 conflict anyway, though at least
MSXML is sticking to the defined extension mechanisms as far as I can
see).

So while I absolutely agree that not every processor should support
XML Schema and not every instance document should have to have an XML
Schema associated with it, (currently) I think that the delay that's
arising from having to define how XPath should support XML Schema
Structures will prove less damaging to XSLT in the long run than
ignoring this requirement.

Cheers,

Jeni

---
Jeni Tennison
http://www.jenitennison.com/


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