SOAP Example

Added June 2013

SOAP requests may be formed by combining an XML-format document (based on the requirements for the web service as defined in the WSDL for the service) with a set of HTTP binding headers. The technique is essentially the same as described in Customizing POST headers, except that the Content-Type may be different and typically you will be adding a SOAPAction header. The following is a an example of a real web service (as of June 2013) provided by WebserviceX.NET which returns details about airports based on the airport code. The format of the XML request document is as follows:

<?xml version="1.0" encoding="utf-8"?>

<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">

<soap:Body>

<airportCode>$AIRPORTCODE$</airportCode>

</getAirportInformationByAirportCode>

</soap:Body>

</soap:Envelope>

To generate an actual request, we copy the above into a file, replacing the $AIRPORTCODE$ with the actual code (see CGIUTL for one technique to simply such replacements). In order to specify the desired Content-Type and the SOAPAction header, we insert it at the top of our file, followed by a blank line and then the XML request:

Content-Type: text/xml; charset=utf-8

SOAPAction: "http://www.webserviceX.NET/getAirportInformationByAirportCode"

Assuming that our generated request file is called "airport.req", we can then call the web service as follows:

flags = XHTTPF_REQPOST ! POST request (typical for SOAP)

flags = flags or XHTTPF_FILEREQ or XHTTPF_FILERESP ! request and response are both filespecs

flags = flags or XHTTPF_HDRBODY ! request body contains header lines

url = "http://www.webserviceX.NET/airport.asmx"

xcall HTTP, 1, status, flags, url, "airport.req", "airport.rsp"

To examine the final headers as sent to the service, add the XHTTPF_DEBUG flag and then check the resulting debug.req file, which should look something like:

POST /airport.asmx HTTP/1.1

Host: www.webservicex.net

Content-Type: text/xml; charset="utf-8"

SOAPAction: "http://www.webserviceX.NET/getAirportInformationByAirportCode"

Content-Length: 418

<?xml version="1.0" encoding="utf-8"?>

<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"

xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">

<soap:Body>

</getAirportInformationByAirportCode>

</soap:Body>

</soap:Envelope>

Note that the POST, Host:, and Content-Length headers are added automatically, but the Content-Type and SOAPAction headers are copied from the request file.

The program AIRPORT in EXLIB:[908,25] demonstrates this service.