Accessing Web Services from URL

Problem/Question/Abstract:

How can I access the web service through my application

Answer:

This article describes how to call the web services from your application. The MSSoap client ole object will allow the application to make remote procedure calls to the web server over the internet. So we need to create a ole object i.e the "MSSoap.Soapclient" in our application. For this, Microsoft Soap ToolKit must be installed in the machine where the application is running.

For this example will be using the "CurrencyExchangeService" webservice which is provided by www.xmethods.net. This web service gives the currency value of the Country2 with respect to Country1.

function getrate(Country1, Country2: string): Double;
var
  SoapClient: OleVariant;
  vRate: string;
  vURL: string;
begin
  vURL := 'http://www.xmethods.net/sd/CurrencyExchangeService.wsdl';
  vRate := 0;
  try
    SoapClient := CreateOleObject('MSSOAP.SoapClient');
  except
  end;
  try
    SoapClient.mssoapinit(vURL);
    //GetRate is the function in the Web service
    vRate := SoapClient.GetRate(Country1, Country2);
  except
  end;
  try
    FreeAndNil(SoapClient);
  except
  end;
  Result := StrToFloat(vRate);
end;