Re: Trouble with data schema

Am Wednesday 06 July 2005 09:27 verlautbarte Giles Hogben :
> I would like to propose a simplification which there is still time to
> put in the spec.
> We include categories in the Base Data Schema for backward
> compatibility - but we disallow them in custom schemas from now on.

I don't get you here. One of the features of the category system was, 
that new custom data elements could be attached to the existing broad 
categories thus giving the custom elements some meaning. This meaning 
would then be easier to understand for user agents.

> If you want to put in broad categories, there's nothing stopping you
> - you just have to make them into data elements which subsume the
> narrower categories. There's no need for a completely different and
> confusing syntax. 

Can you give an example how this would look like?

> Yes it's because of XSD. Basically because each 
> data element takes a subset of categories from a global set, this is
> only possible with a custom data type (or at least that's the only
> way we could find to do it and we consulted some XML lists)...

Can we say that we don't allow for NEW categories? Because in your 
example in the Spec, you say:

<element minoccurs="0" maxoccurs="1" name="musical-preference">
  <element minoccurs="0" maxoccurs="1" ref="classicalmusic-preference"/>
    <annotation>
      <documentation>
        Musical Preferences
      </documentation>
    </annotation>
    <element ref="CATEGORY" minoccurs="0" maxoccurs="*" 
             type="allCategories"/>
  </element>

So if you wanted new <category> - Elements, you would have to make them 
available in a custom XML Schema? How would that fit in our framework?

Best, 

Rigo