xpath-sample.js

var select = require('xpath.js')
      , dom = require('xmldom').DOMParser

    var xml = "<?xml version='1.0' encoding='UTF-8'?>"+
"<feed xmlns='http://www.w3.org/2005/Atom' xmlns:openSearch='http://a9.com/-/spec/opensearchrss/1.0/'>"+
"  <entry>"+
"    <updated>2014-08-19T14:37:34.663Z</updated>"+
"    <category scheme='http://schemas.google.com/spreadsheets/2006' term='http://schemas.google.com/spreadsheets/2006#spreadsheet'/>"+
"    <title type='text'>Tmp SS</title>"+
"    <content type='text'>Tmp SS</content>"+
"    <link rel='http://schemas.google.com/spreadsheets/2006#worksheetsfeed' type='application/atom+xml' href='https://spreadsheets.google.com/feeds/worksheets/1DkxkuNGoXt_Hhu0yvvL60MqJuQIzdov4fewfewfewfewb9H_ot9khto/private/full'/>"+
"    <link rel='alternate' type='text/html' href='https://docs.google.com/spreadsheets/d/1DkxkufwefewfweNGoXt_Hhu0yvvL60MqJuQIzdov4b9H_ot9khto/edit'/>"+
"  </entry>"+
"</feed>"


    var doc = new dom().parseFromString(xml)    
    var nodes = select(doc, "//*[local-name()='entry']/*[local-name()='link' and @rel='http://schemas.google.com/spreadsheets/2006#worksheetsfeed']/@href")
    console.log(nodes[0].value)