3.4.1 URI Domain Expression

This section defines a domain expression for identifying resources as policy subjects for the external attachment mechanism. The following is a pseudo-schema for the URI domain expression:

(01) <wsp:PolicyAttachment … >
(02)   <wsp:AppliesTo>
(03)     <wsp:URI … >xs:anyURI</wsp:URI> *
(04)   </wsp:AppliesTo>
(05)   …
(06) </wsp:PolicyAttachment>

The following describes the URI domain expression element listed in the pseudo-schema outlined above:

/wsp:PolicyAttachment/wsp:AppliesTo/URI

This optional element is an absolute IRI and references a resource as a policy subject. There is no requirement that the IRI be resolvable; retrieval mechanisms are beyond the scope of this specification.

/wsp:PolicyReference/wsp:AppliesTo/URI/@{any}
Additional attributes MAY be specified but MUST NOT contradict the semantics of the [owner element]; if an attribute is not recognized, it SHOULD be ignored.
URI domain expressions are used to identify resources that are identified using IRI or IRI References (such as endpoint, message or operation definitions) with which policies can be associated. For example, URI domain expressions may be used to identify WSDL 1.1 definitions, WSDL 2.0 components, etc.  The following example illustrates the use of URI domain expression with a WSDL 2.0 [WSDL 2.0 Core Language] IRI Reference: 
(01) <wsp:PolicyAttachment>
(02)   <wsp:AppliesTo>
(03)     <wsp:URI>
(04)       http://example.org/TicketAgent.wsdl20#wsdl.endpoint(TicketAgentService/Endpoint)
(05)     </wsp:URI>
(06)   </wsp:AppliesTo>
(07)   <wsp:PolicyReference 
(08)      URI="http://www.example.com/policies#RmPolicy" />
(09) </wsp:PolicyAttachment>

In this example, the policy expression at http://www.example.com/policies#RmPolicy applies to all interactions with the endpoint at http://example.org/TicketAgent.wsdl20#wsdl.endpoint(TicketAgentService/Endpoint). Similarly, an XPointer [XPointer Framework] can be used as an IRI Reference to identify a description in a WSDL 1.1 [WSDL 1.1] document.

A.2 Other References
[XPointer Framework]
XPointer Framework, Paul Grosso, Eve Maler, Jonathan Marsh, Norman Walsh, Editors. World Wide Web Consortium, 22 November 2002. This version of the XPointer Framework Proposed Recommendation is http://www.w3.org/TR/2003/REC-xptr-framework-20030325/ The latest version of XPointer Framework is available at http://www.w3.org/TR/xptr-framework/.

The following is the XML Schema Element Declaration for the URI element:

<xs:element name="URI">
  <xs:complexType>
     <xs:simpleContent>
       <xs:extension base="xs:anyURI">
         <xs:anyAttribute namespace="##any" processContents="lax" />
       </xs:extension>
     </xs:simpleContent>
  </xs:complexType>
</xs:element>