- From: Booth, David (HP Software - Boston) <dbooth@hp.com>
- Date: Wed, 11 Apr 2007 16:59:08 -0400
- To: "John Cowan" <cowan@ccil.org>
- Cc: "Misha Wolf" <Misha.Wolf@reuters.com>, "Richard Cyganiak" <richard@cyganiak.de>, <www-tag@w3.org>, <semantic-web@w3.org>, <public-xg-mmsem@w3.org>, <newsml-g2@yahoogroups.com>
> From: John Cowan [mailto:cowan@ccil.org] > > Booth, David (HP Software - Boston) scripsit: > > > I'm confused by your point #3 below, as it seems to be > > implying that a document without a DTD could legitimately > > have an attribute of type ID with value "123456", and > > after looking at the specs I don't see how it > > can. Did I miss something? > > An xml:id processor will report a constraint violation when it sees > "xml:id='123456'" in an element, but it will perform ID type > assignment anyway, as noted in Section 4 of the xml:id Recommendation. Oh yes, now I see: http://www.w3.org/TR/xml-id/#processing [[ The xml:id processor performs ID type assignment on all xml:id attributes, even those that do not satisfy the constraints. ]] > > In addition, a conformant XML processor must report an > attribute declared > to be of type ID as having that type, no matter what the value may be. > For example, the document: > > <!DOCTYPE items [ > <!ATTLIST item id ID #IMPLIED> > ]> > <items> > <item id="123456">...</item> > ... > </items> > > is not valid, but the id attribute of the item element is of type ID. > So you can use either xml:id or a (possibly partial) DTD to force > an attribute to be of type ID, and ignore any xml:id or > validation errors. And I see that a processor SHOULD report those errors: http://www.w3.org/TR/xml-id/#errors [[ A violation of the constraints in this specification results in an xml:id error. Such errors are not fatal, but should be reported by the xml:id processor. In the interest of interoperability, it is strongly recommended that xml:id errors not be silently ignored. ]] I guess an approach that depends on routinely ignoring xml:id processing errors and not validating the XML does not seem to me like a wise design choice, because it severely limits future processing options, and a key consideration in any standardization effort should be the facilitation of future processing that may be slightly different than it is today. David Booth, Ph.D. HP Software +1 617 629 8881 office | dbooth@hp.com http://www.hp.com/go/software
Received on Wednesday, 11 April 2007 21:00:27 UTC