The W3C Web Services Description Working Group has published an initial public working draft specification for Web Services Description Language (WSDL) Version 1.2 Part 2: Message Patterns, along with updated WDs for Web Services Description Language (WSDL) Version 1.2 Part 1: Core Language and Web Services Description Language (WSDL) Version 1.2 Part 3: Bindings. WSDL is "an XML format for describing network services as a set of endpoints operating on messages containing either document-oriented or procedure-oriented information."

The WSDL Part 2 draft for Message Patterns defines "the sequence, direction, and cardinality of abstract messages sent or received by an operation. WSDL patterns are described in terms of the WSDL component model, specifically the message reference and fault reference components. By design, WSDL message patterns abstract out specific message types; placeholders for messages identified by the pattern are associated with specific message types by the operation using the pattern. Unless explicitly stated otherwise, WSDL message patterns also abstract out binding-specific information like timing between messages, whether the pattern is synchronous or asynchronous, and whether the message are sent over a single or multiple channels."

The Part 1 Core Language draft "describes the Web Services Description Language (WSDL) Version 1.2, an XML language for describing Web services; it defines the core language which can be used to describe Web services based on an abstract model of what the service offers." The Part 3 WSDL Version 1.2 Bindings document depends on the WSDL Version 1.2 Core and "describes how to use WSDL in conjunction with SOAP 1.2, HTTP/1.1 GET/POST, and MIME."

Message Patterns

Message Patterns defined in the new working draft Web Services Description Language (WSDL) Version 1.2 Part 2: Message Patterns include the following. In each case, "WSDL patterns are described in terms of the WSDL component model, specifically the message reference and fault reference components. The working group plans to review the message patterns herein and eliminate those that are have not demonstrated to be useful, for example, supported by a binding with two interoperable implementations."

• In-Only
• In-Out
• Request-Response
• In-Multi-Out
• Out-Only
• Out-In
• Out-Multi-In
• Multicast-Solicit-Response

Bibliographic Information

• Web Services Description Language (WSDL) Version 1.2 Part 2: Message Patterns. W3C Working Draft 11-June-2003. Edited by Martin Gudgin (Microsoft), Amy Lewis (TIBCO), and Jeffrey Schlimmer (Microsoft). Version URL: http://www.w3.org/TR/2003/WD-wsdl12-patterns-20030611. Latest version URL: http://www.w3.org/TR/wsdl12-patterns. Also in PDF and XML format.

• Web Services Description Language (WSDL) Version 1.2 Part 1: Core Language. W3C Working Draft 11-June-2003. Edited by Roberto Chinnici (Sun Microsystems), Martin Gudgin (Microsoft), Jean-Jacques Moreau (Canon), and Sanjiva Weerawarana (IBM Research). Version URL: http://www.w3.org/TR/2003/WD-wsdl12-20030611. Latest version URL: http://www.w3.org/TR/wsdl12. Also available in PDF and XML format.

• Web Services Description Language (WSDL) Version 1.2 Part 3: Bindings. W3C Working Draft 11-June-2003. Edited by Jean-Jacques Moreau (Canon) and Jeffrey Schlimmer (Microsoft). W3C Working Draft 11 June 2003 Version URL: http://www.w3.org/TR/2003/WD-wsdl12-bindings-20030611. Latest version URL: http://www.w3.org/TR/wsdl12-bindings. Also available in PDF and XML format.