XML Demystified

CHAPTER 6 XSLT
instructed by the value of the select attribute. The select attribute customers/customer
refers to the customer element, which is the child of the customers element.
The element says, “For each occurrence of the customer element
within the customers element.” You can achieve the same result by using the
following code. The match attribute states, “Begin at the root (entry point of the
source document) and go to the customers element.”
...
...
...
The element extracts text from the source document and transforms it
into the result document. This is the XPath. In the example we show you in the previous
section, we’re extracting the customer ID and the customer’s first and last names.
The instruction extracts the customer ID. The @
symbol indicates that the customer ID is an attribute of the customer element and
not a child element.
The   instruction extracts the customer’s
first name which is contained in the firstname element of the source document.
You’re probably wondering if   is a typo. It isn’t.
This is a whitespace that’s inserted into the result document, so there’s a space
between the customer’s first and last names. 160 is the ISO-8859-1 character value
for a nonbreaking whitespace character, which is the equivalent of   in
HTML. (ISO is the International Standards Organization that among other things
establishes values for various nonprintable characters such as a space.)
We’re retrieving all customers from the source document in our example. In a
real-world application, you might need to retrieve a particular customer. You can do
this by modifying the attribute value of .
Suppose you want only customer 286. Here’s what you need to write:
Likewise, you can specify values for XML elements, such as the first name of a
customer as we show here:
89