Google Analytics Client ID Generator

gistfile1.txt

/**
 * Generates a client ID in the format historically used by the Google Analytics
 * JavaScript libraries. Note that any alphanumeric value may be used, but
 * ideally each should be unique to a given client.
 *
 * More information on Client IDs:
 * https://developers.google.com/analytics/devguides/collection/protocol/v1/email#client-id-cid
 */
function generateGaClientId() {

  var ts = Math.round(+new Date() / 1000.0);
  var rand;
  
  try{  
    var uu32 = new Uint32Array(1);
    rand = crypto.getRandomValues(uu32)[0];
  } catch(e) {
    rand = Math.round(Math.random() * 2147483647);
  }
  
  return [rand, ts].join('.');

}
/**
 * Tested on:
 * - IE6+
 * - Firefox 3.6 & 49
 * - Opera 40
 * - Chrome 53
 * - Safari 5.1 & 9
 */