Go Up to Setting Up the Data Module
To add a TSoapDataModule component to your application, choose File > New > Other and select SOAP Server Data Module from the WebServices page of the new items dialog. The SOAP data module wizard appears.
You must supply a class name for your SOAP data module. This is the base name of a TSoapDataModule descendant that your application creates. It is also the base name of the interface for that class. For example, if you specify the class name MyDataServer, the wizard creates a new unit declaring TMyDataServer, a descendant of TSoapDataModule, which implements IMyDataServer, a descendant of IAppServerSOAP.
Note: To use TSoapDataModule, the new data module should be added to a Web Service application. The IAppServerSOAP interface is an invokable interface, which is registered in the initialization section of the new unit. This allows the invoker component in the main Web module to forward all incoming calls to your data module.
You may want to edit the definitions of the generated interface and TSoapDataModule descendant, adding your own properties and methods. These properties and methods are not called automatically, but client applications that request your new interface by name or GUID can use any of the properties and methods that you add.