- From: Dan Connolly <connolly@w3.org>
- Date: Fri, 19 May 2000 05:16:29 -0500
- To: Ron Daniel <rdaniel@metacode.com>
- CC: David Megginson <david@megginson.com>, xml-dev@xml.org, xml-uri@w3.org
Ron Daniel wrote: > > I strongly agree with David Megginson when he says: > > > The schema > > for schemas (and others) should reference an XML schema for the xml: > > Namespace using the xsi:schemaLocation attribute, as in > > > > xsi:schemaLocation="http://www.w3.org/XML/1998/namespace > > > > http://www.w3.org/XML/Schemas/xmlschema-20000518.xsd" > > > > > [Ron Daniel] > > I very commonly construct DTDs (and assume I'll be doing > Schemas RSN) that mix and match elements from multiple > namespaces. They regularly feature elements from the > RDF, Dublin Core, and XHTML namespaces, plus some > custom elements from customer-specific namespaces. > A particular mix is chosen to meet a customer's needs, > and the DTD enforces the constraints of a particular > mix. Very well... I don't see how this conflicts with the owner of the namespace name publishing definitive material about their namespace. > The Dublin Core may define dc:Description, but > that has nothing to do with whether paragraph breaks > will or won't be allowed in those descriptions. It may or may not; the Dublin Core may well define a content model for dc:description that excludes or requires paragraph breaks. > XHTML defines a way for me to indicate paragraph breaks, > but it can't know in advance if a particular customer > will or won't need images and tables in their Dublin > Core Descriptions. These specific constraints are the > role of the DTD and schema, not the namespace. You may use customer-specific schemas in stead of namespace-owner-provided schemas for your work, but again, I don't see how making namespace-owner-provided schemas conflicts with using customer-specific schemas. Case in point: we haven't made an XML Schema available at http://www.w3.org/XML/1999/xhtml yet, so in the stuff that I'm hacking on, I use schemaLocation to point to my hacked XHTML schema: " <html xmlns="http://www.w3.org/1999/xhtml" xmlns:xsi='http://www.w3.org/1999/XMLSchema-instance' xmlns:t='http://www.w3.org/2000/TR/smil-animation10' xsi:schemaLocation="http://www.w3.org/1999/xhtml html.xsd http://www.w3.org/2000/TR/smil-animation10 smil-animation.xsd " > " -- http://www.w3.org/XML/2000/04schema-hacking/h+s.html If there were an XML schema available at http://www.w3.org/1999/xhtml , it would have no impact on the output of xmlschema-check when it validates h+s.html > Lets keep the space of names and the syntactic constraints > on particular document classes as very separate things. > Merging them will reduce, not enhance, the ability to > mix and match elements from multiple namespaces in order > to meet people's needs. Please elaborate in detail on how it will "reduce the ability to ...". I'm confident, based on experience with running code, that it does not. -- Dan Connolly, W3C http://www.w3.org/People/Connolly/
Received on Friday, 19 May 2000 06:16:46 UTC