In the past few years, Extensible Markup Language (XML) has become an important means of communication. In this chapter, you use Amazon's Web Services interface to build a shopping cart on your website that uses Amazon as a back end. (This application is named Tahuayo, which is the name of an Amazonian tributary.) You use two different methods to do this: SOAP and REST. REST is also known as XML over HTTP. You use PHP's built-in SimpleXML library and the external NuSOAP library to implement these two methods.
In this chapter, we discuss the following topics:
Understanding XML and SOAP basics
Using XML to communicate with Amazon
Parsing XML with PHP's SimpleXML library