[standards-jig] sequence vs. choice

Peter Saint-Andre stpeter at jabber.org
Wed Feb 6 23:37:47 UTC 2002


On Wed, 6 Feb 2002, David Waite wrote:

> Hmm, if this is informational, we shouldn't go changing things now by 
> saying that elements have to occur in a particular order :-)

Hey, I was just wondering. :) The current DTDs don't even include the
error element, so I'm just cleaning things up.

> 1. elements within message/presence/iq can happen in any order

OK. 

> 2. there may be rules about how many body/subject/etc tags you can have

Are there now? AFAIK, you can have only one of each of these.

> 3. there may be rules about XML contained within a body/subject/etc tag 
> (only CDATA, no mixed data)

Agreed.

BUT you can have as many additional elements (e.g., <x/>) as you want,
right? So I go back to this question:

> >XML schemas question: can do the following to override the maxOccurs on
> >the <xsd:choice/> element?
> >
> >     <xsd:choice minOccurs='0' maxOccurs='1'>
> >       <xsd:element ref='body' />
> >       <xsd:element ref='subject' />
> >       <xsd:element ref='thread' />
> >       <xsd:any namespace='##any' minOccurs='0' maxOccurs='unbounded' />
> >       <xsd:element ref='error' />
> >     </xsd:choice>

Maybe I just put in minOccurs and maxOccurs for each element, eh?

Peter




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