Your First XML Document

This chapter teaches you how to create simple XML documentswith tags you define that make sense for yourdocument. You’ll learn how to write a style sheet for the documentthat describes how the content of those tags shouldbe displayed. Finally, you’ll learn how to load the documentsinto a Web browser so that they can be viewed.Since this chapter will teach you by example, and not fromfirst principals, it will not cross all the t’s and dot all the i’s.Experienced readers may noTIce a few excepTIons and specialcases that aren’t discussed here. Don’t worry about these;you’ll get to them over the course of the next several chapters.For the most part, you don’t need to worry about thetechnical rules right up front. As with HTML, you can learnand do a lot by copying simple examples that others haveprepared and modifying them to fit your needs.Toward that end I encourage you to follow along by typing inthe examples I give in this chapter and loading them into thedifferent programs discussed. This will give you a basic feelfor XML that will make the technical details in future chapterseasier to grasp in the context of these specific examples.Hello XMLThis secTIon follows an old programmer’s tradiTIon of introducinga new language with a program that prints “Hello World” onthe console. XML is a markup language, not a programming language;but the basic principle still applies. It’s easiest to getstarted if you begin with a complete, working example you canexpand on rather than trying to start with more fundamentalpieces that by themselves don’t do anything. And if you doencounter problems with the basic tools, those problems are a lot easier to debug and fix in the context of the short, simple documents used hererather than in the context of the more complex documents developed in the rest ofthe book.In this section, you’ll learn how to create a simple XML document and save it in afile. We’ll then take a closer look at the code and what it means.