Web services are getting a lot of hype. In the end, however, they are simply an HTTP request and response whereby each may be carrying XML data. So using a Web service from Cocoa is simply a matter of being able to send HTTP requests and receive responses. It also may require generating and parsing XML. See Figure 28.1.
Figure 28.1. Your Average Web Service in Action
HTTP requests and responses are handled by
NSURLConnection (Figure 28.2).
Figure 28.2. Classes for Making HTTP Requests
Generating and parsing ...