WSDL Document Structure

WSDL document can be partitioned into two sections:

The abstract sections define SOAP messages in a platform and language independent manner. They don’t contain any machine or language specific elements. The abstract elements are types, message and portType

The concrete sections are site-specific, machine-specific or language-specific. The concrete elements are binding and service.

A WSDL document describes a web service using below major elements:

		<definitions>     <types>    definition of types........ </types>     <message>  definition of a message.... </message>      <portType> definition of a port....... </portType>     <binding>  definition of a binding.... </binding>     <service>  definition of a service.... </service> </definitions>

·         definitions: Must be the root element of all WSDL documents. It defines the name of the web service, declares namespaces used throughout the document and contains all other elements described ahead.

·         types: The <types> element defines the data types that are used by the web service.

·         message: Each message can consist of one or more parts. The parts can be compared to the parameters of a function call in a traditional programming language.

·         portType: It describes a web service, the operations that can be performed, and the messages that are involved .The <portType> element can be compared to a function library (or a module, or a class) in a traditional programming language

·         binding: The <binding> element defines the data format and protocol for each port type.

·         service: service element that makes it possible to group together the definitions of several web services in one single WSDL document.