PHP: Exposing a Service Component as a Web service

Exposing a Service Component as a Web service

SCA for PHP can generate WSDL from the annotations within a service component, so that it can be easily deployed and exposed as a Web service. To provide SCA with the information it needs to generate the WSDL, it is necessary to add the annotation @binding.soap under the @service annotation and to specify the parameters and return values of the methods using the @param and @return annotations. These annotations will be read when WSDL is generated, and the order and types of the parameters determine the contents of the <schema> section of the WSDL.

SCA for PHP always generates document/literal wrapped WSDL for components that are exposing a Web service. Note that this does not stop components from consuming Web services which are not SCA components and which are documented with WSDL written in a different style.

The scalar types which can be used in the @param annotation are the four common PHP scalar types: boolean, integer, float and string. These are simply mapped to the XML schema types of the same name in the WSDL. The example below, which is a trivial implementation of the StockQuote service that the ConvertedStockQuote component calls, illustrates string and float types.

Example #1 StockQuote Service


<?php



include "SCA/SCA.php";



/**

 * Scaffold implementation for a remote StockQuote Web service.

 *

 * @service

 * @binding.soap

 *

 */

class StockQuote {



    /**

     * Get a stock quote for a given ticker symbol.

     *

     * @param string $ticker The ticker symbol.

     * @return float The stock quote.

     */

    function getQuote($ticker) {

        return 80.9;

  }

}

?>

WSDL much like the following (though with a service location other than 'localhost', probably) would be generated from this service:

Example #2 Generated WSDL

<?xml version="1.0" encoding="UTF-8"?>
<definitions xmlns="http://schemas.xmlsoap.org/wsdl/" xsi:type="tDefinitions"
    xmlns:tns2="http://StockQuote" xmlns:tns="http://schemas.xmlsoap.org/wsdl/"
    xmlns:tns3="http://schemas.xmlsoap.org/wsdl/soap/"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" targetNamespace="http://StockQuote">
  <types>
    <xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
      targetNamespace="http://StockQuote">
      <xs:element name="getQuote">
        <xs:complexType>
          <xs:sequence>
            <xs:element name="ticker" type="xs:string"/>
          </xs:sequence>
        </xs:complexType>
      </xs:element>
      <xs:element name="getQuoteResponse">
        <xs:complexType>
          <xs:sequence>
            <xs:element name="getQuoteReturn" type="xs:float"/>
          </xs:sequence>
        </xs:complexType>
      </xs:element>
    </xs:schema>
  </types>

  <message name="getQuoteRequest">
    <part name="getQuoteRequest" element="tns2:getQuote"/>
  </message>
  <message name="getQuoteResponse">
    <part name="return" element="tns2:getQuoteResponse"/>
  </message>
  <portType name="StockQuotePortType">
    <operation name="getQuote">
      <input message="tns2:getQuoteRequest"/>
      <output message="tns2:getQuoteResponse"/>
    </operation>
  </portType>
  <binding name="StockQuoteBinding" type="tns2:StockQuotePortType">
    <operation name="getQuote">
      <input>
        <tns3:body xsi:type="tBody" use="literal"/>
      </input>
      <output>
        <tns3:body xsi:type="tBody" use="literal"/>
      </output>
      <tns3:operation xsi:type="tOperation" soapAction=""/>
    </operation>
    <tns3:binding xsi:type="tBinding" transport="http://schemas.xmlsoap.org/soap/http" style="document"/>
  </binding>
  <service name="StockQuoteService">
    <port name="StockQuotePort" binding="tns2:StockQuoteBinding">
      <tns3:address xsi:type="tAddress" location="http://localhost/StockQuote/StockQuote.php"/>
    </port>
  </service>
</definitions>

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