A quick overview of WSDL (Web Services Description Language)

WSDL - The <portType> Element 

The <portType> element defines a web service, operations can be performed and messages are involved. <portType> defines connection point to a web service. It can be compared to a function library (a class or a module) in a traditional programming language. Each operation can be compared to a function in a traditional programming language.

Operation Types 

The request-response type is most common operation type, but WSDL defines four types:

One-Way Operation

<message name="TermValues">
   <part name="term" type="xs:string"/>
   <part name="value" type="xs:string"/>
</message>

<portType name="glossaryTerm">
   <operation name="setTerm">
     <input name="new" message="newValues"/>
   </operation>
</portType >

In example above portType "glossaryTerm" defines a one-way operation called "setTerm".The "setTerm" operation allows input of new glossary term messages using a "newValues" message with input parameters "term" and "value".

Request-Response Operation

<message name="getRequest">
   <part name="term" type="xs:string"/>
</message>

<message name="getResponse">
   <part name="value" type="xs:string"/>
</message>

<portType name="glossaryTerm">
   <operation name="getTerm">
     <input message="getRequest"/>
     <output message="getResponse"/>
   </operation>
</portType>

In example above portType "glossaryTerm" defines a request-response operation called "getTerm".The "getTerm" operation requires an input message called "getRequest" with a parameter called "term" and will return an output message called "getResponse" with a parameter called "value".