10. Using XML
After the hype, the Extensible Markup Language (XML) is now really used almost everywhere. An application that receives a lot of buzz is Web Services, a technology that is covered in detail in Chapter 9, “Working with Other Databases.” However, XML can be used elsewhere, as well. It is a good format to store any kind of data.
The tasks behind using XML are always the same: reading data from XML and writing data into it. So, this chapter focuses on these tasks and shows how to implement them.
Unfortunately, PHP 4’s XML support was somewhat limited. Some extensions did not prove to be very stable. This changed drastically with PHP 5 and a revamped XML support. Therefore, we completely omit PHP 4 in this chapter (and in the rest of ...