Table of contents

Appendices

2.2 Message

The Message Component[top]

A message component describes the abstract format of a particular message that a Web service sends or receives. The format of a message is typically described in terms of XML element information items and attribute information items. A message binding (see [Binding]) describes how the abstract content is mapped into a concrete format. However, in some cases, the abstract definition may match the concrete representation very closely or exactly for one or more bindings. Such bindings will supply little or no mapping information. However, another binding of the same message definition may require extensive mapping information. For this reason, it is not until the binding is inspected that one can determine "how abstract" a message really is.

Messages are named constructs and can be referred to by QName (see [QName resolution]). For instance, port type components refer to messages in this way (see [Message Reference]).

The properties of the Message Component are as follows:

• {name} An NCName as defined by [XMLNS].

• {target namespace} A namespace name, as defined in [XMLNS].

• {parts} A set of named part definitions.

For each message component in the {messages} property of a definitions container the combination of {name} and {target namespace} properties MUST be unique.

XML Representation of Message Component[top]

The XML representation for a message definition component is an element information item with the following Infoset properties;

• A [local name] of message

• A [namespace name] of http://www.w3.org/2003/03/wsdl

• One or more attribute information items amongst its [attributes] as follows;

  • A name attribute information item as described below in [ ].

  • Zero or more namespace qualified attribute information items. The [namespace name] of such attribute information items MUST NOT be http://www.w3.org/2003/03/wsdl.

• Zero or more element information items amongst its [children], in order as follows;

  • An optional documentation element information item (see [Documentation]).

  • Zero or more part element information items (see [XML Representation of Part Component])

• Zero or more namespace qualified element information items amongst its [children]. Such element information items MUST be a member of one of the element substitution groups related to messages described in [Language Extensibility].

name attribute information item with message [owner][top]

The name attribute information item together with the targetNamespace attribute information item of the definitions element information item forms the QName of the message,

The name attribute information item has the following Infoset properties;

• A [local name] of name

• A [namespace name] which has no value

The type of the name attribute information item is xs:NCName.

Mapping Message's XML Representation to Component Properties[top]

The mapping between the properties of the Message Component (see [The Message Component]) and the XML Representation of the message element information item (see [XML Representation of Message Component]) is as described in [tab_Message_Mapping].