Re: [xml-dev] Converting a variety of data formats, containingvarious ki

[Dave Pawson <dave.pawson@gmail.com>]

I'd like to see more of this Mike.. perhaps a worked
example based on your event ideas?
  An option to template match.. or something else?

regards

On 5 October 2016 at 09:14, Michael Kay <mike@saxonica.com> wrote:
>
> Mainstream XML technology definitely disfavours generic approaches: to move
> to generic approaches where the specific semantics is in attributes *and*
> retaining validation requires moving to RELAX NG or Schematron in which
> attributes are first-class citizens (rather than dtds or xsd where all
> patterns/types are keyed by element context only.)
>
>
> I've never really understood why we consider
>
> <graduation date="2012-03-31"/>
>
> as less generic than
>
> <event type="graduation" date="2012-03-21"/>
>
> There seems to be some very deep-rooted feeling that element and attribute
> names are "fixed" while attribute values are "variable". Perhaps our schema
> technology encourages this thinking, or perhaps it is languages like XPath,
> but the fact is that we don't really believe and trust in the "X" in "XML".
>
> Even Xpath's syntax disfavours generic approaches (by providing no support),
> no crIticism implied. I have been working with generic schemas for much of
> the last decade, and I really think XSL T Xpath would be enhanced by
> providing some simple macro system to uncomplicate paths: for example  so
> that instead of writing
>
>     event[property[@name="kind"][@value="birthday"]]
>
> i could declare a virtual child named birthday-event with that xpath, and
> then use a virtual axis:
>
>   vchild::birthday-event
>
>
> I've argued in favour of user-defined axes for many years but I've found it
> hard to get the idea taken seriously. Though I've never taken it quite this
> far as to allow the "node-test" part of the step to be interpreted in a
> user-defined way.
>
> Substitution groups can be great for handling this kind of content: where in
> schema-aware XPath, schema-element(event) selects graduation elements
> because they are part of the substitution group. I've seen little take-up of
> that, however.
>
> Michael Kay
> Saxonica
>



-- 
Dave Pawson
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