XPath and PHP

How can I use XPath to read in an XML document, run a query to filter out some of the data and then save the filtered data as a new XML file?

 

It would be a huge help if you posted an example of what the XML document should look like before and after processing.

 

Just a standard XML document really.

 

You'll probably find it easier to use simpleXML, but the basic method for parsing with XPath is:

$xml = file_get_contents('yourxml.xml');
$dom = new DOMDocument();
@$dom->loadXML($xml);
$xpath = new DOMXPath($dom);
$xml_nodes = $xpath->evaluate("/your/xpath/goes//here");
foreach ($xml_nodes as $nodes) {
  echo $nodes->firstChild->data;
}

PHP:

 

OK I've already got that far, I need it to run a query to filter out some of the data and then save the filtered data as a new XML file.

 

use fwrite()