Re: [office-comment] Ambiguity problems caused by ID/IDREF

["MURATA Makoto (FAMILY Given)" <eb2m-mrt@asahi-net.or.jp>]

Michael,

Thank you for your thoughtful mail.  I am happy to see that you 
are serious about bug reports.

> a) Alex Brown has suggested to use W3C xml:id rather than Relax NG DTD
> Compatibility:
snip
> Would the use of W3C xml:id without using the Relax NG DTD
> Compatibility Specification in your opinion add ID semantics to the
> xml:id attribute?

I think so.  In other words, I do not understand the non-normative 
appendix "D Validation Technologies" of xml:id.   But you might want 
to hear the opinion of the editors of xml:id.

> The W3C XML ID specification in appendix D.2 recommends:
> 
> "RELAX NG Grammar authors are encouraged to declare attributes named
> xml:id with the type xs:ID.",


Yes.  I do not understand why this is encouraged.

> and the "Guidelines for using W3C XML Schema Datatypes with RELAX NG"
> state that
> 
> "The semantics defined by [W3C XML Schema Datatypes] for the ID, IDREF
> and IDREFS datatypes are purely lexical and do not include the
> cross-reference semantics of the corresponding [XML 1.0] datatypes."
> 
> This sounds to me like that using W3C xml:id without Relax NG DTD
> Compatibility does not specify ID semantics for xml:id.

In my understanding, the xml:id processor should provide ID semantics
for xml:id.
> 
> On the other hand, the W3C xml:id specification also states that:
> 
> "An xml:id processor should assure that the following constraint holds:
> 
>      * The values of all attributes of type "ID" (which includes all
> xml:id attributes) within a document are unique."
> 
> so at least the uniqueness of the IDs may have to be checked. However,
> the semantics of IDREF attributes seem to remain purely lexical unless
> the the Relax NG DTD Compatibility Specification is used. Is my
> understanding correct?

I think that you are right.  I do not know why the xml:id spec does not 
provide xml:idref as well.
 
> Is my understanding correct that a specification that uses Relax NG
> (like ODF) may require conformance with only one, or two of the three
> features defined by Relax NG Compatibility. In particular, is it
> possible to request conformance with the attribute default value
> feature, but not with ID/IDREF feature? Or vice versa, could a
> specification request conformance with the ID/IDREF feature only?

Strictly speaking, the DTD compatibility spec defines conformance 
of application programs but do not define conformance of schemas.  
It rather defines compatibility of schemas.  A schema may be compatible 
with the ID/IDREF/IDREFS feature without being comptible with the attribute 
default values feature.

> In other words: Is your suggestion to claim conformance to the ID/IDREF
> feature in the future, but to not claim conformance to the attribute
> default value and documentation features? Or is your suggestion to
> claim conformance to the full DTD Compatibility specification, but to
> not define any a:defaultValue attributes or a:documentation elements in
> the schema, so that all that what is said about these features in the
> Relax NG DTD Compatibility specification simply is not applicable to the 
> ODF schema.

The latter.  But I do not think a:documentation elements should be 
prohibited.
> 
> And is it in your opinion permitted that the ODF specification currently
> makes only use of the default value feature without claiming conformance
> to the ID/IDREF or documentation feature?

The ODF schema is NOT compatible with the default value feature.  
It is NOT compatible with the ID/IDREF feature.  Since it does not 
have any occurrences of a:documentation elements, it is compatible 
with the documentation feature.

Hope this helps.

Cheers,

-- 
MURATA Makoto (FAMILY Given) <EB2M-MRT@asahi-net.or.jp>