Whis Is WSDL (Web Services Definition Language)?

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This section describes what is WSDL (Web Services Definition Language).

WSDL (Web Services Definition Language): An XML based standard designed to describes protocol bindings and message formats of Web services. WSDL is often pronounced as "Whiz-Dull".

A WSDL document is an XML document written in WSDL to describe Web service. Here is a copy of the WSDL document for the demonstration Web service used in previous sections. You can download one yourself by going to http://www.xmethods.net/sd/2001/DemoTemperatureService.wsdl with your Web browser:

<?xml version="1.0"?>
<definitions name="TemperatureService" 
 targetNamespace="http://www.xmethods.net/sd/TemperatureService.wsdl"
 xmlns:tns="http://www.xmethods.net/sd/TemperatureService.wsdl"   
 xmlns:xsd="http://www.w3.org/2001/XMLSchema" 
 xmlns:soap="http://schemas.xmlsoap.org/wsdl/soap/" 
 xmlns="http://schemas.xmlsoap.org/wsdl/">
 <message name="getTempRequest">
  <part name="zipcode" type="xsd:string"/>
 </message>
 <message name="getTempResponse">
  <part name="return" type="xsd:float"/>
 </message>
 <portType name="TemperaturePortType">
  <operation name="getTemp">
   <input message="tns:getTempRequest"/>
   <output message="tns:getTempResponse"/>
  </operation>
 </portType>
 <binding name="TemperatureBinding" type="tns:TemperaturePortType">
  <soap:binding style="rpc"
   transport="http://schemas.xmlsoap.org/soap/http"/>
  <operation name="getTemp">
   <soap:operation soapAction=""/>
   <input>
    <soap:body use="encoded"
     namespace="urn:xmethods-Temperature-Demo"
     encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/>
   </input>
   <output>
    <soap:body use="encoded"
     namespace="urn:xmethods-Temperature-Demo"
     encodingStyle="http://schemas.xmlsoap.org/soap/encoding/"/>
   </output>
  </operation>
 </binding>
 <service name="TemperatureService">
  <documentation>Returns current temperature in a given U.S. zipcode
  </documentation>
  <port name="TemperaturePort" binding="tns:TemperatureBinding">
   <soap:address
  location="http://services.xmethods.net:80/soap/servlet/rpcrouter"/>
  </port>
 </service>
</definitions>

I cannot read this document well before learning the WSDL specifications. But it seems to be describing precisely how this Web service should be used.

Last update: 2007.

Sections in This Chapter

What Is PHP SOAP Extension?

GetTemp.php - First Example with SOAP

PHP SOAP Extension Functions for Client Programs

GetTempDump.php - Dumping Debugging Information

Whis Is WSDL (Web Services Definition Language)?

Using SOAP Extension in non-WDSL Mode