RE: Arbortext dissent on OASIS request to allow locating schemas via public ids

The ability to use public identifiers to communicate the intended schema 
for a specific namespace was facet of LC-117, 

http://www.w3.org/2000/05/12-xmlschema-lcissues.html#locating-schema-resources

In http://lists.w3.org/Archives/Public/www-xml-schema-comments/2000JulSep/0215.html, 
I retracted my objections after clarifications were made.  Much the initial comment
was based on my interpreting 'hint' as partially signifying a location independent
identifier, that is that processors would use xsi:schemaLocation to identify
the desired schemas identity but not is location.  The perceived dual nature of
xsi:schemaLocation deeply troubled me.

In that message, I did discuss the need to communicate a document's assertion 
that it adhered to a specific schema for a namespace and conceded that it could be done
through an application specific attribute.  However, I did feel that that need was legitimate 
and common and should be addressed in the primer.

I would definitely support a generic solution to the issue through public id's or urn's or possibly both.

There was reluctance to introduce a dependency on public identifiers since URI's are 
the preferred addressing mechanism.  

A possible solution would be to:

1. define a URN representation of Public identifiers (I didn't see one listed at http://www.w3.org/Addressing/schemes.html)
2. allow an xsi:schemaIdentity attribute that consists of pairs of namespace uri's and 
URI's (possibly public id urn's) identifying schema resources.
3. allow an schemaIdentity attribute on the schema element.

Adding a URI scheme for public id's would also be beneficial for using RDF to describe
existing XML DTD's.

Received on Friday, 16 February 2001 01:55:45 UTC