Consuming XML SOAP Web Services

The starting point for implementing a SOAP Web Service client is a Web Services Description Language (WSDL) document, which specifies the web methods a given Web Service implements, including the names and types of the expected parameters. Delphi provides a WSDL Importer wizard that takes as input a WSDL file and generates an Object Pascal unit with types and methods that correspond with the functionality exposed by a SOAP Web Service. The main application logic can use the generated classes in order to issue Web Service requests and receive results returned from a remote Web Services server app.

Let’s have a look at the process of integrating with a SOAP Web Service on the example of a numeric processing service, capable of converting a number in its textual description. I found a free, open service, which is not terribly useful but is good for a demo. The WSDL file, if you want to take a look, is at https://www.dataaccess.com/webservicesserver...