Summary

This introductory chapter answered the following questions about XSLT:

• What kind of language is it?

• Where does it fit into the XML family?

• Where does it come from and why was it designed the way it is?

• Where should it be used?

You now know that XSLT is a declarative high-level language designed for transforming the structure of XML documents; that it has two major applications: data conversion and presentation; and that it can be used at a number of different points in the overall application architecture, including at data capture time, at delivery time on the server, and at display time on the browser. You also have some idea why XSLT has developed in the way it has.

Now it's time to start taking an in-depth look inside the language to see how it does this job. In the next chapter, we look at the way transformation is carried out by treating the input and output as tree structures, and using patterns to match particular nodes in the input tree and define what nodes should be added to the result tree when the pattern is matched.