anyURI datatype problem

I am incorporating RDF into a schema and receiving errors when trying to
validate against the following instance:

<rdf:Description about="">

The about attribute is defined in my schema as:
<xs:attribute name="about" type="xs:anyURI" />

According to the XML Schema Part 2: Datatypes Recommendation
(http://www.w3.org/TR/xmlschema-2/#anyURI), the anyURI datatype should
conform to the URI syntax as defined by RFC 2396
(http://www.ietf.org/rfc/rfc2396.txt).

In RFC 2396, section 4.2 titled "Same-document References" says:

"A URI reference that does not contain a URI is a reference to the
current document.  In other words, an empty URI reference within a
document is interpreted as a reference to the start of that document..."

So according to the specs, a blank URI should be valid.

But let's see what happens when I try to validate my document using
different parsers:

JAXP 1.2: No errors
Sun MSV: No errors
.NET XmlValidatingReader: Validation error: The 'about' attribute has an
invalid value according to its data type.
xsdvalid: attribute "about" has invalid value "": an URI cannot be the
empty string [cvc-datatype-valid.1.2.1] [cvc-attribute.3]

So I am having a bit of a problem in Visual Studio .NET because it uses
its own validator so I am getting errors and swiggly lines constantly
which is driving me nuts.

I can get around the problem by declaring the attribute as a xs:string
but this looks like a bug so is there anyway we can get this resolved? 

Thanks,
Nasseam Elkarra
http://www.myspotter.com

Received on Monday, 28 July 2003 07:42:48 UTC