XPath Basics - Proof Of The Pudding (
Page 5 of 9 )
By combining the axis and node test
into a location step, and combining multiple location steps into a location path,
it becomes possible to locate specific nodes with the document tree quite easily.
Using the following XML sample, let's consider some examples.
<?xml version="1.0"?>
<?xml-stylesheet type="text/xsl" href="recipe.xsl"?>
<movie
id="67" genre="sci-fi">
<title>X-Men</title>
<!-- in case you didn't
know, this is based on the comic - Ed -->
<cast>Hugh Jackman, Patrick Stewart
and Ian McKellen</cast>
<director>Bryan Singer</director>
<year>2000</year>
<?play_trailer?>
</movie>
The path
/child::movie/child::cast/child::text()
references the text node
Hugh Jackman, Patrick Stewart and Ian McKellen
In order to make this a little easier to read (and write), XPath assumes a default
axis of "child" if none is specified - which means that I could also write the
above path as
/movie/cast/text()
Similarly, the path
/movie/comment()
references the comment string
in case you didn't know, this is based on the comic - Ed
while the path
/movie/node()[8]
references the string
Bryan Singer
The * character matches all child elements of the context node, while the @ prefix
indicates that attributes, rather than elements, are to be matched. The path
/movie/*
would match all the children of the "movie" element, while the path
/movie/@*
would refer to all the attributes of the movie element. In case I need a specific
attribute - say, "genre", I could use the path
/movie/@genre
or the path
/movie/attribute::genre
both of which would reference the value
sci-fi
Finally, the path
/*
would reference the first element under the document root, which also happens
to be the outermost element, while the path
//*
selects all the elements in the document.
This article copyright Melonfire 2001. All rights reserved.
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