To find elements by attribute with nokogiri, no matter where the element/attribute is, use these:


@doc = Nokogiri::XML(File.open("myFile.xml").read)
# get elements with attribute:
elements = @doc.xpath("//*[@*[attribute_name]]")
# get just the attribute:
attributes = @doc.xpath("//@*[attribute_name]")


If you want them with a specific namespace, do this:


# get elements with attributes from a given namespace:
elements = @doc.xpath("//*[@*[namespace-uri()='http://foo.example.com']]")
# get attributes from a given namespace:
attributes = @doc.xpath("//@*[namespace-uri()='http://foo.example.com']")