What are the elements in WSDL ?

Sample WSDL document structure

<wsdl:definitions xmlns:wsdl="http://schemas.xmlsoap.org/wsdl" targetNamespace="your namespace  here" xmlns:tns="your  namespace  here"xmlns:soapbind="http://schemas.xmlsoap.org/wsdl/soap">

  <wsdl:types>

    <xs:schema  targetNamespace="your  namespace here" 

                xmlns:xsd="http://www.w3.org/2001/XMLSchema"

      <!--  Define  types  and  possibly  elements  here  -->

    </schema>

  </wsdl:types>

  <wsdl:message  name="some  operation  input">

    <!--  part(s)  here  -->

  </wsdl:message>

  <wsdl:message  name="some  operation  output">

    <!--  part(s)  here  -->

  </wsdl:message>

  <wsdl:portType  name="your  type  name">

    <!--  Operations  here  in  terms  of  their  messages  -->

  </wsdl:portType>

  <wsdl:binding  name="your  binding  name"  type="tns:port  type  name  above">

    <!--  Style  & transport  in  general  and use  per  operation  -->

  </wsdl:binding>

  <wsdl:service>

    <!--  Port  here using  the  above  binding  and  a  URL  -->

  </wsdl:service>

</wsdl:definitions>

WSDL Elements

 1. Types

 2. Message

 3. Operation

 4. Port Type

 5. Binding

 6. Port

 7. Service

Types

• Data type definitions
• Used to describe exchanged messages

Messages

• Abstract, typed definitions of data being exchanged
• It describes the message logically instead of physically

Operations

• Abstract description of an action
• Refers to an input and/or output messages
• Several types of operations can be declared in a WSDL document. They are
• Request / Response
  A client makes a request, and the Web service responds to it.
• Solicit / Response
  A Web service sends a message to the client, and the client responds.
• One-way
  A client sends a message to the Web service but expects no response.
• Notification
  A Web service sends a message to the client but expects no response.

Port type

• Collection of operations, that provides a one-stop point where a client can obtain information on all operations.
• Abstract definition of a service

Binding

• Concrete protocol and data format (encoding) for a particular Port type
• Protocol examples: SOAP 1.1 over HTTP or SOAP 1.1 over SMTP
• Encoding examples: SOAP encoding, RDF encoding

Port

• Defines a single communication endpoint
• Endpoint address for binding
• URL for HTTP, email address for SMTP

Service

• Aggregate set of related ports