This introductory chapter described the whys and wherefores
of XSLT: it tried to answer questions such as:
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'll 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