Twitter Button Google Analytics

ga-twitter.js

// This assumes that you have included the Tweet button via the standard Twitter JS include
// Thanks to Google for most of this code, see the Social Interaction Analytics guide at 
// https://developers.google.com/analytics/devguides/collection/gajs/gaTrackingSocial

// To track a Tweet, subscribe to the tweet event (note the additional function required 
// to determine the query parameter being sent to Twitter):
function trackTwitter(intent_event) {
    if (intent_event) {
      var opt_pagePath;
      if (intent_event.target && intent_event.target.nodeName == 'IFRAME') {
            opt_target = extractParamFromUri(intent_event.target.src, 'url');
      }
      _gaq.push(['_trackSocial', 'twitter', 'tweet', opt_pagePath]);
    }
  }

  twttr.ready(function (twttr) {
    twttr.events.bind('tweet', trackTwitter);
  });
function extractParamFromUri(uri, paramName) {
  if (!uri) {
    return;
  }
  var regex = new RegExp('[\\?&#]' + paramName + '=([^&#]*)');
  var params = regex.exec(uri);
  if (params != null) {
    return unescape(params[1]);
  }
  return;
}