OASIS Open Document Format for Office Applications (OpenDocument) TC

Dear TC members,

When I wrote the xml:id proposal, my hope was that the restriction to a
single ID attribute would actually make it easier to make the schema
compatible with the RNG DTD Compatibility specification, which again
would resolve the errors that jing reports if called without "-i" option.

I did some research and experiments. However, I did not find a solution
for this. The reason is the following definition in the DTD
Compatibility specification[1]:

> A RELAX NG schema is compatible with this feature [ID/IDREF] if and 
> only if, after
> schema simplification, for each data or value element that specifies
> a datatype associated with a non-null ID-type, all of the following
> hold:
>
>     * its parent is an attribute element
>     * the first child of its attribute parent is a name element
>     * the first child of the element ancestor is a name element

Essentially this means that one can define an attribute of type ID only
if one provides the name of the attribute, and the name of an element.

Why is this an issue? We have a few places in the schema where we allow
arbitrary content, for instance within the 

Michael Brauer - Sun Germany - ham02 - Hamburg wrote:

> I would be glad if my analysis of the issue is incorrect, but right now,
> I don't see any other solution than avoiding any reference to the RNG
> DTD Compatibility specification, and to provide the advice to use RNG
> with the "-i" switch.

Hi Michael,

there is another solution. You can explicitly remove elements in
namespaces defined by ODF from any pattern. Anyway, I suppose that
intent was not allow anything in places where "any" is used now, but
only anything which is not defined in ODF.

So it is possible to change definition of any to something like:

  

We have been successfully using this approach in extended DocBook and
XHTML schemas in Relaxed validator. I do not have the latest ODF schemas
at hand so I haven't chance to test whether this approach clashes with
anything else in schema.

But, anyway extensibility in elements like office:meta and draw:object
could be much more elegantly described by using NVDL and effectively
stripping such extension elements from document before sending to
validation against RELAX NG schema.

					Jirka

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  Jirka Kosek      e-mail: jirka@kosek.cz      http://xmlguru.cz
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