WHAT YOU WILL LEARN IN THIS CHAPTER
Understanding the various ways to consume Web services in your iPhone applications
How to communicate with a Web service using SOAP
How to parse the result of a Web service call using the NSXMLParser class
Communicating with the outside world is one of the ways to make your iPhone applications interesting and useful. This is especially true today when so many Web services provide such useful functionality. However, consuming Web services in an iPhone is not for the fainthearted. Unlike other development tools (such as Microsoft Visual Studio), Xcode does not have built-in tools that make consuming Web services easy. Everything must be done by hand, and you need to know how to form the relevant XML messages to send to the Web services and then parse the returning XML result.
This chapter explains how to communicate with XML Web services from within your iPhone application. Working through the examples in this chapter will give you a solid foundation for consuming other Web services that you will need in your own projects.
For an introduction to XML Web services, check out this link:
Before you create an Xcode project to consume a Web service, it is good to examine a real Web service to see the different ways you can consume it. My favorite example is to use an ASMX XML Web service created using .NET. For the purposes of this discussion, we'll look ...