Copyright © 2010 W3C® (MIT, ERCIM, Keio), All Rights Reserved. W3C liability, trademark and document use rules apply.
This specification defines two WS-Policy assertions that can be used to advertise the requirement to use a certain version of SOAP in message exchanges.
1 Composable Architecture
2 Introduction
2.1 Requirements
3 Notations
3.1 Notational Conventions
3.2 Considerations on the Use of Extensibility Points
3.3 Compliance
3.4 XML Namespaces
4 SOAP Assertions
4.1 SOAP11 Assertion
4.2 SOAP12 Assertion
5 Examples
6 Acknowledgements
7 References
7.1 Normative References
A XML Schema
B Change Log
By using the XML, SOAP [SOAP11], [SOAP12], and WSDL [WSDL11] extensibility models, the Web service specifications (WS-*) are designed to be composed with each other to provide a rich set of tools for the Web services environment.
Using the Web Service Policy - Framework [WS-Policy] and Web Services Policy - Attachment [WS-PolicyAttachment] specifications, an endpoint can indicate support for a variety of features. Two endpoints can then determine if they share compatible features through the policy intersection algorithm defined by the WS-Policy framework. This allows for a programmatic way to locate interoperable endpoints.
However, one key aspect of the message exchanges is whether either endpoint requires the use of SOAP 1.1 [SOAP11] or SOAP 1.2 [SOAP12]. While this information might be obtainable through examination of a WSDL [WSDL11] document, or implied through some out of band knowledge, there is no way to make this determination during the application of the policy intersection algorithm. This specification defines two new policy assertions that allows for this critical piece of information to be available during normal policy processing.
This section specifies the notations and namespaces used in this specification.
The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119 [RFC 2119].
This specification uses the following syntax to define outlines for messages:
The syntax appears as an XML instance, but values in italics indicate data types instead of literal values.
Characters are appended to elements and attributes to indicate cardinality:
"?" (0 or 1)
"*" (0 or more)
"+" (1 or more)
The character "|" is used to indicate a choice between alternatives.
The characters "(" and ")" are used to indicate that contained items are to be treated as a group with respect to cardinality or choice.
The characters "[" and "]" are used to call out references and property names.
Ellipses (i.e., "...") indicate points of extensibility.
XML namespace prefixes (see Table 3-1) are used to indicate the namespace of the element being defined.
This specification can be used in terms of XML Information Set (Infoset) [XML Infoset], even though the specification uses XML 1.0 terminology. Valid Infoset for this specification is the one serializable in XML 1.0, hence the use of XML 1.0.
The elements defined in this specification MAY be extended at the points indicated by their outlines and schema. Implementations MAY add child elements and/or attributes at the indicated extension points but MUST NOT contradict the semantics of the parent and/or owner, respectively.
Extension elements and attributes MUST NOT use the Web Services Metadata Exchange namespace URI.
An implementation is not compliant with this specification if it fails to satisfy one or more of the MUST or REQUIRED level requirements defined herein. A SOAP Node MUST NOT use the XML namespace identifier for this specification (listed in 3.4 XML Namespaces) within SOAP Envelopes unless it is compliant with this specification.
Normative text within this specification takes precedence over the XML Schema and WSDL descriptions, which in turn take precedence over outlines, which in turn take precedence over examples.
Implementations are expected to support both UTF-8 and UTF-16 as described in XML 1.0.
Implementations of this specification MUST conform to the corrected version of WSDL as defined by the 'WSDL Correction' sections of WS-I Basic Profile 1.2 [BP12] and WS-I Basic Profile 2.0 [BP20].
The XML namespace URI that MUST be used by implementations of this specification is:
Table 3-1 lists XML namespaces that are used in this specification. The choice of any namespace prefix is arbitrary and not semantically significant.
| Prefix | XML Namespaces | Specification(s) |
|---|---|---|
| s | (Either SOAP 1.1 or 1.2) | (Either SOAP 1.1 or 1.2) |
| s11 | http://schemas.xmlsoap.org/soap/envelope/ | [SOAP11] |
| s12 | http://www.w3.org/2003/05/soap-envelope | [SOAP12] |
| wsa | http://www.w3.org/2005/08/addressing | [WS-Addressing] |
| wsp | http://www.w3.org/ns/ws-policy | [WS-Policy] |
| wssa | http://www.w3.org/2002/ws/ra/edcopies/ws-sas | This specification |
| xs | http://www.w3.org/2001/XMLSchema | [XMLSchema - Part 1] |
The working group intends to update the value of the Web Services Metadata Exchange namespace URI each time a new version of this document is published until such time that the document reaches Candidate Recommendation status. Once it has reached Candidate Recommendation status, the working group intends to maintain the value of the Web Services Metadata Exchange namespace URI that was assigned in the Candidate Recommendation unless significant changes are made that impact the implementation or break post-CR implementations of the specification. Also see http://www.w3.org/2001/tag/doc/namespaceState.html and http://www.w3.org/2005/07/13-nsuri .
An endpoint MAY indicate that it requires the use of a certain version of SOAP by using the following policy assertions with its policy alternatives.
The normative outline of this assertion is:
<wssa:SOAP11 ...> ... <wssa:SOAP11>
The following describes additional, normative constraints on the outline listed above:
This policy assertion has Endpoint Policy Subject. When present in a policy alternative, it indicates that the SOAP 1.1 protocol MUST be used when communicating with this endpoint.
The normative outline of this assertion is:
<wssa:SOAP12 ...> ... <wssa:SOAP12>
The following describes additional, normative constraints on the outline listed above:
This policy assertion has Endpoint Policy Subject. When present in a policy alternative, it indicates that the SOAP 1.2 protocol MUST be used when communicating with this endpoint.
The following example shows a sample policy expression that indicates SOAP 1.1 is required:
<wsp:Policy> <wssa:SOAP11/> </wsp:Policy>
The following example shows a sample policy expression that indicates either SOAP 1.1 or SOAP 1.2 can be used:
<wsp:Policy>
<wsp:ExactlyOne>
<wssa:SOAP11/>
<wssa:SOAP12/>
</wsp:ExactlyOne>
</wsp:Policy>The following example shows a WS-Addressing [WS-Addressing] endpoint reference that indicates SOAP 1.2 is required for all messages sent to the endpoint:
<wsa:EndpointReference>
<wsa:Address> ... </wsa:Address>
<wsp:Policy>
<wssa:SOAP12/>
</wsp:Policy>
<wsa:EndpointReference>This specification has been developed as a result of joint work with many individuals and teams, including: Alessio Soldano (Red Hat), Ashok Malhotra (Oracle Corp.), Asir Vedamuthu (Microsoft Corp.), Bob Freund (Hitachi, Ltd.), Bob Natale (MITRE Corp.), David Snelling (Fujitsu, Ltd.), Doug Davis (IBM), Fred Maciel (Hitachi, Ltd.), Geoff Bullen (Microsoft Corp.), Gilbert Pilz (Oracle Corp.), Greg Carpenter (Microsoft Corp.), Jeff Mischkinsky (Oracle Corp.), Katy Warr (IBM), Li Li (Avaya Communications), Mark Little (Red Hat), Martin Chapman (Oracle Corp.), Paul Fremantle (WSO2), Paul Nolan (IBM), Prasad Yendluri (Software AG), Ram Jeyaraman (Microsoft Corp.), Sreedhara Narayanaswamy (CA), Sumeet Vij (Software AG), Tom Rutt (Fujitsu, Ltd.), Vikas Varma (Software AG), Wu Chou (Avaya Communications), Yves Lafon (W3C/ERCIM).
A normative copy of the XML Schema [XMLSchema - Part 1], [XMLSchema - Part 2] description for this specification can be retrieved from the following address:
A non-normative copy of the XML schema is listed below for convenience.
<xs:schema
targetNamespace='http://www.w3.org/2002/ws/ra/edcopies/ws-sas'
xmlns:tns='http://www.w3.org/2002/ws/ra/edcopies/ws-sas'
xmlns:xs='http://www.w3.org/2001/XMLSchema'
elementFormDefault='qualified'
blockDefault='#all' >
<xs:complexType name='emptyElementType'>
<xs:sequence>
<xs:any namespace='##other' minOccurs='0' maxOccurs='unbounded'/>
</xs:sequence>
<xs:anyAttribute namespace='##other' processContents='lax'/>
</xs:complexType>
<xs:element name='SOAP11' type='tns:emptyElementType'/>
<xs:element name='SOAP12' type='tns:emptyElementType'/>
</xs:schema>