Let's try to learn some basic XPath syntax by looking at some examples.
The XML Example Document
We will use the following XML document in the examples below.
"books.xml":
<?xml version="1.0" encoding="UTF-8"?>
<bookstore>
<book category="COOKING">
<title lang="en">Everyday Italian</title>
<author>Giada De Laurentiis</author>
<year>2005</year>
<price>30.00</price>
</book>
<book category="CHILDREN">
<title lang="en">Harry Potter</title>
<author>J K. Rowling</author>
<year>2005</year>
<price>29.99</price>
</book>
<book category="WEB">
<title lang="en">XQuery Kick Start</title>
<author>James McGovern</author>
<author>Per Bothner</author>
<author>Kurt Cagle</author>
<author>James Linn</author>
<author>Vaidyanathan Nagarajan</author>
<year>2003</year>
<price>49.99</price>
</book>
<book category="WEB">
<title lang="en">Learning XML</title>
<author>Erik T. Ray</author>
<year>2003</year>
<price>39.95</price>
</book>
</bookstore>
Loading the XML Document
Using XMLHttpRequest to load XML documents is supported in all modern browsers.
Code for most modern browsers:
var xmlhttp=new XMLHttpRequest()
Code for old Microsoft browsers (IE 5 and 6):
var xmlhttp=new ActiveXObject("Microsoft.XMLHTTP")
Selecting Nodes
Unfortunately, there are different ways of dealing with XPath in Internet Explorer and other browsers.
In our examples we have included code that should work with most major browsers.
Internet Explorer uses the selectNodes() method to select nodes from the XML document:
xmlDoc.selectNodes(xpath);
Firefox, Chrome, Opera and Safari use the evaluate() method to select nodes from the XML document:
xmlDoc.evaluate(xpath, xmlDoc, null, XPathResult.ANY_TYPE,null);
Select all the titles
The following example selects all the title nodes:
Example
/bookstore/book/title
Select the title of the first book
The following example selects the title of the first book node under the bookstore element:
Example
/bookstore/book[1]/title
Select all the prices
The following example selects the text from all the price nodes:
Example
/bookstore/book/price[text()]
Select price nodes with price>35
The following example selects all the price nodes with a price higher than 35:
Example
/bookstore/book[price>35]/price
Select title nodes with price>35
The following example selects all the title nodes with a price higher than 35:
Example
/bookstore/book[price>35]/title
