php__silex__book/web/js/ga.js

const _gaq = [
  ["_setAccount", "UA-XXXXXXXX-X"],
  ["_trackPageview"]
];

(function () {
  const ga = document.createElement("script");
  ga.type = "text/javascript";
  ga.async = true;
  ga.src = (document.location.protocol === "https:" ? "https://ssl" : "http://www") + ".google-analytics.com/ga.js";
  const s = document.getElementsByTagName("script")[0];
  s.parentNode.insertBefore(ga, s);
}());