fathom/assets/js/tracker.js

'use strict';

(function() {
  function jsonToQueryString(json) {
    var keys = Object.keys(json);

    // omit empty
    keys = keys.filter(function(k) {
      return json[k].length > 0;
    });

    return '?' +
        keys.map(function(k) {
            return encodeURIComponent(k) + '=' +
                encodeURIComponent(json[k]);
        }).join('&');
  }

  // abort hit if Do Not Track is enabled.
  // if( navigator.DonotTrack == 1 ) {
  //   return;
  // }

  var i = document.createElement('img');
  var d = {
    l: navigator.language,
    p: location.pathname + location.search,
    sr: screen.width + "x" + screen.height,
    t: document.title,
    r: document.referrer
  };


  i.src = 'http://localhost:8080/collect' + jsonToQueryString(d);

  document.body.appendChild(i);
})();