SOAP Client in C# without access to a WSDL-file

Question

I'm working with a third party to integrate some of our systems with theirs and they provide us with a SOAP interface to make certain requests and changes in their connected systems. The problem for me is that they do not supply a WSDL-file for me to work against. If I had a WSDL-file it would be a simple matter just to run the supplied .NET command (wsdl.exe) and generate a proxy class to interact with the service.

Is there an "easy" way to do this without a WSDL-file? I have all the functions that we can access and what parameters I need to send and what I should expect in return.

Is it common to have a SOAP-service without WSDL-files? (I'm asking this since we're going to add more external systems into the mix in the future)

Has anyone done a proxy-class or any other form of client against a WDSL-less service and have any good pointers on how to do it?

Answer 1

string EndPoints = "http://203.189.91.127:7777/services/spm/spm";

string New_Xml_Request_String = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><soapenv:Envelope xmlns:soapenv=\"http://schemas.xmlsoap.org/soap/envelope/\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\"><soapenv:Body><OTA_AirLowFareSearchRQ EchoToken=\"0\" SequenceNmbr=\"0\" TransactionIdentifier=\"0\" xmlns=\"http://www.opentravel.org/OTA/2003/05\"><POS xmlns=\"http://www.opentravel.org/OTA/2003/05\"><Source AgentSine=\"\" PseudoCityCode=\"NPCK\"  TerminalID=\"1\"><RequestorID ID=\"\"/></Source><YatraRequests><YatraRequest DoNotHitCache=\"true\" DoNotCache=\"false\" MidOfficeAgentID=\"\" AffiliateID=\"\" YatraRequestTypeCode=\"SMPA\"/></YatraRequests></POS><TravelerInfoSummary><AirTravelerAvail><PassengerTypeQuantity Code=\"ADT\" Quantity=\"1\"/><PassengerTypeQuantity Code=\"CHD\" Quantity=\"1\"/><PassengerTypeQuantity Code=\"INF\" Quantity=\"1\"/></AirTravelerAvail></TravelerInfoSummary> <SpecificFlightInfo><Airline Code=\"\"/></SpecificFlightInfo><OriginDestinationInformation><DepartureDateTime>" + DateTime.Now.ToString("o").Remove(19, 14) + "</DepartureDateTime><OriginLocation CodeContext=\"IATA\" LocationCode=\"DEL\">" + Source + "</OriginLocation><DestinationLocation CodeContext=\"IATA\" LocationCode=\"BOM\">" + Destincation + "</DestinationLocation></OriginDestinationInformation><TravelPreferences><CabinPref Cabin=\"Economy\"/></TravelPreferences></OTA_AirLowFareSearchRQ></soapenv:Body></soapenv:Envelope>";


 protected string HttpSOAPRequest_Test(string xmlfile, string proxy)
    {
        try
        {
            System.Xml.XmlDocument doc = new System.Xml.XmlDocument();
            doc.InnerXml = xmlfile.ToString();
            HttpWebRequest req = (HttpWebRequest)WebRequest.Create(EndPoints);
            req.Timeout = 100000000;
            if (proxy != null)
                req.Proxy = new WebProxy(proxy, true);
            req.Headers.Add("SOAPAction", "");
            req.ContentType = "application/soap+xml;charset=\"utf-8\"";
            req.Accept = "application/x-www-form-urlencoded"; //"application/soap+xml";
            req.Method = "POST";
            Stream stm = req.GetRequestStream();
            doc.Save(stm);
            stm.Close();
            WebResponse resp = req.GetResponse();
            stm = resp.GetResponseStream();
            StreamReader r = new StreamReader(stm);
            string myd = r.ReadToEnd();
            return myd;
        }

   catch (Exception se)
        {
            throw new Exception("Error Occurred in AuditAdapter.getXMLDocumentFromXMLTemplate()", se);
        }
    }

Answer 2

If you write a class that derives from System.Web.Services.Protocols.SoapHttpClientProtocol (and has the correct attributes, e.g., WebServiceBinding, SoapDocumentMethod, etc. applied to it and its methods), you can fairly easily call SOAP methods without needing the WSDL file.

The easiest way to do this would probably be to write your own ASP.NET web service that replicates the third party's SOAP API, generate a proxy class from it, then manually edit the file to ensure that the URL, namespaces, method names, parameter types, etc. are correct for the third-party API you want to call.