Definition of object hierarchies in XML schema

Hi Folks;

I am using XML as a data container and need "object-oriented" data types
that allow overriding of defaults. The way this is done is that an element
may contain nested elements of itself, e.g.

<A att1="a" att2="b">
  <A leaf="1" att1="aa" att3="c1"/>
  <A leaf="2" att3="c2"/>
</A>

this is semantically equivalent to 
<A att1="aa" att2="b" att3="c1"/>
<A att1="a" att2="b" att3="c2"/>

Is there any way in XML schema to specify that each leaf of the tree must
have all three attributes att1, att2, att3 but not each individual node ar
am I forced to simply make each attribute optional?
Thanks 
Rainer


Rainer Prosi
Heidelberger Druckmaschinen AG

Received on Thursday, 26 October 2000 13:23:36 UTC