Server Side Web Services
In DataFlex, a web application consists of web service objects (WSOs).
WSOs – Web Service Objects
WSOs are used to communicate with web service clients. A web service client will be part of some remote application. When needed, the application will make a call to the web service client, and the client will make the request to a web service. If this web service is part of a DataFlex web application, the request will be sent as a function call within the WSO. This function will do whatever it needs to do and return information to the client. Because a web service is an application-to-application exchange of data, there is no need to use ASP. When building web service-based web applications, you will be programming in just one area – the WSO.
A single web application supports both Web Business Objects (WBOs) and WSOs. A single web application can support multiple web services (one service per WSO). A single WSO can support multiple operations (each operation is a function).
See Also: Web Service Objects .wso File
WSDLs – Service Descriptions
It is expected that any web service provide a description of its service. This is done by providing a formal service description document that describes exactly how the service should be accessed. This document is called a WSDL document (Web Service Description Language) and is defined by W3C at W3C WSDL Specification.
A WSDL document tells you everything you need to know about a web service. It tells you where the service is located, how it is accessed, and what operations are available for the service. It defines the parameters and data types for each operation. It also specifies exactly how the SOAP request and response should be encoded.
A WSDL document is an XML file. While it is human-readable, it is really designed to be written (generated) and read (parsed) by a computer. On the server side, the DataFlex web application server generates WSDL documents. On the client side, DataFlex contains a parser that reads WSDL documents and creates client web service classes.