IRIs and xs:anyURI incompatibilities.

The WSDL WG dealt with a last call issue regarding IRIs vs URIs that I took an action to bring to the CG.  I'm belatedly fulfilling that action.

The issue from the I18N WG [1] pointed out that although we state in the abstract model that certain properties have IRI values, we describe them as xs:anyURI.  Turns out there is a legacy mismatch between between the anyURI type and the eventual definition of IRIs.  The escaping procedure mandated by xs:anyURI includes the characters "<", ">", '"', space, "{", "}", "|", "\", "^", and "`", while IRIs don't allow these characters.  The result is that invalid IRIs may validate as legal xs:anyURI values.

One solution is to define in our schema a constraint on xs:anyURI outlawing these characters.  However, the Working Group felt this legacy incompatibility between IRIs and xs:anyURI was not really the Description WGs remit to fix, and if we instituted a fix that was different than one that might be developed by those responsible for the conflicting specs that we could actually complicate the deployment of a more comprehensive solution should one be adopted.

As a result, we added a warning to authors simply to steer away from these dragons:

		Note: The xs:anyURI type is defined so that xs:anyURI values are essentially IRIs [RFC 3987]. The conversion from xs:anyURI values to an actual URI is via an escaping procedure defined by [XLink 1.0], which is identical in most respects to IRI Section 3.1. For interoperability, WSDL authors are advised to avoid the characters "<", ">", '"', space, "{", "}", "|", "\", "^", and "`", which are allowed by the xs:anyURI type but disallowed in IRIs.

Potential actions the CG could take on this might include:

1.	
	Try to engage the XML and I18N activities in developing a solution (if indeed one hasn't been developed already).
2.	
	Make the WGs in the WS activity aware of this issue in case they similarly mix the IRI and xs:anyURI types.
3.	
	Make the Activity Lead and XML CG rep aware of this issue in the hopes they can drive a solution or describe the measures being taken to address this issue.

Received on Friday, 27 January 2006 01:20:08 UTC