ZEND PHP 5 Certification STUDY GUIDE

XML and Web Services ” 199
if ($use_xhtml) {
echo $dom->saveXML();
} else {
echo $dom->saveHTML();
}
XPath Queries
One of the most powerful parts of the DOM extension, is its integration with
XPath—in fact, DomXPath is far more powerful than the SimpleXML equivalent:
$dom = new DomDocument();
$dom->load("library.xml");
$xpath = new DomXPath($dom);
$xpath->registerNamespace("lib", "http://example.org/library");
$result = $xpath->query("//lib:title/text()");
foreach ($result as $book) {
echo $book->data;
}
This example seems quite complex, but in actuality it shows just how flexible the
DOM XPath functionality can be.
First, we instantiate a DomXpath object, passing in our DomDocument object so that
the former will know what to work on. Next, we register only the namespaces we
need, in this case the default namespace, associating it with the lib prefix. Finally,
we execute our query and iterate over the results.
A call to DomXpath::query() will return a DomNodeList object; you can find out how
many items it contains by using the length property, and then access any one of them
with the item() method. You can also iterate through the entire collection using a
foreach() loop:
Licensed to 482634 - Amber Barrow (itsadmin@deakin.edu.au)
$result = $xpath->query("//lib:title/text()");