I am trying to parse Youtube Gdata to see if video with given id exists. But there isn't normal tag but with namespace. On the link http://gdata.youtube.com/feeds/api/videos?q=KgfdlZuVz7I there is tag:

<openSearch:totalResults>1</openSearch:totalResults>

There is namespace openSearch:

xmlns:openSearch='http://a9.com/-/spec/opensearchrss/1.0/'

but I dont know how to deal with it in Nokogiri and Ruby.

Here is part of code:

xmlfeed = Nokogiri::HTML(open("http://gdata.youtube.com/feeds/api/videos?q=#{video_id}"))
xmlfeed.at_xpath("openSearch:totalResults")

It gives error:

Undefined namespace prefix: openSearch:totalResults