Latest web development tutorials

XPath Examples

In this section, let us learn by example to some basic XPath syntax.


XML instance documents

We will use this XML document in the following example:

"Books.xml":

<?xml version="1.0" encoding="ISO-8859-1"?>

<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>

View "books.xml" file in your browser .


Load an XML document

All modern browsers support the use of XMLHttpRequest to load XML documents.

For most modern browsers code:

var xmlhttp=new XMLHttpRequest()

For the old Microsoft browser (IE 5 and 6) of the Code:

var xmlhttp=new ActiveXObject("Microsoft.XMLHTTP")


Select node

Unfortunately, Internet Explorer and other different way of handling XPath.

In our example, it contained for most major browsers code.

Internet Explorer uses selectNodes () method from the XML document to select nodes:

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 title

The following examples select all title nodes:

Examples

/bookstore/book/title

try it"


Select the first title of a book

The following examples select bookstore element below the first book node title:

Examples

/bookstore/book[1]/title

try it"

There is a problem. The above examples of different results in IE and other browsers.

IE5 and later the [0] regarded as the first node, and according to the W3C standards should be [1].

One solution!

In order to solve the IE5 + [0] and [1] of the problem, you can set the language selection for the XPath (SelectionLanguage).

The following examples select bookstore element below the first book node title:

Examples

xml.setProperty("SelectionLanguage","XPath");
xml.selectNodes("/bookstore/book[1]/title");

try it"


Select all prices

The following examples select all the text node price:

Examples

/bookstore/book/price/text()

try it"


Select the price is higher than the price node 35

The following examples select all price higher than the price of 35 nodes:

Examples

/bookstore/book[price>35]/price

try it"


Select the node price is higher than 35 title

The following examples select all the title nodes prices higher than 35:

Examples

/bookstore/book[price>35]/title

try it"