simplexml xpath not working

[ngreenwood6]

I am trying to parse a blogspot feed using xpath but it doesnt seem to be working with anything that I try. I am not sure if it is because of the namespaces or what but I was hoping someone could help me. Here is the code:

 

        $xml = simplexml_load_file('http://feeds.feedburner.com/blogspot/MKuf');

   

    $next = $xml->xpath("//link[@rel=next]");

    print_r($next);

 

This is just returning an empty array and it should not be. I tried it doing just link or just entry and it still is returning empty. The only one I can run on it that works is *. Any help is appreciated.

[salathe]

Since the XML document has a default namespace (for Atom), you need to tell XPath that it exists and in your query you need to ask for link elements within that default namespace. Since you're looking for only the next link of the feed (I'm guessing you don't want any from the entries) then there's also no need for // in the XPath query.

 

$xml->registerXPathNamespace('atom', 'http://www.w3.org/2005/Atom');
$next = $xml->xpath("atom:link[@rel='next']");

[ngreenwood6]

Thanks for the reply. Is there a way to dynamically know the namespaces and register them?

[salathe]

Sure, each SimpleXMLElement object has two methods for retrieving namespaces: getDocNamepaces and getNamespaces. You can loop over the return value from whichever of those you like most, registering them one at a time.