SearchMonkey Guide

	Note
	Always try to use Data::get() before resorting to Data::xpath() or Data::xpathString(). Data::get() is easier to use, and it tends to be more robust if the underlying XML structure happens to change. You should only use the XPath functions if you have a problem that requires the full power of the DOM.

mixed xpath ( string $query [, DOMNode $contextnode ] ) 

The function Data::xpath() executes an arbitrary XPath query on Data's XML. Data::xpath() is essentially a thin wrapper around DOMXPath->query(), where the query is automatically set up to act on the DOM representation of your application's XML data.

Because it relies on XPath, Data::xpath() is much more flexible and powerful than Data::get(). The downside is that XPath queries tend to be more complicated than Data::get() expressions. For example, these two function calls are equivalent:

Data::get("smid:abcde/rel:Resource/@property");

Data::xpath("/*/*[@id='smid:abcde']/*[@rel='rel:Resource']/*[@property='media:width']");

Additionally, Data::xpath() typically returns a DOMNodeList, which means that you must do further work to extract the desired data as strings.

Beyond the ability to run more complex queries, the chief advantage of using Data:xpath() is that it works on certain paths where Data::get() does not. If any property, rel, or id attributes in your expression include any ".", "/", or ":" characters, then Data::get() fails, returning FALSE. For these sorts of situations, use Data::xpath() or Data::xpathString() instead.