Set Theatre Manager's `tmsource` cookie based on `tmsource` or `utm_source` query parameters.

tmsource.js

(setTimeout(function () {
  var TM_PARAM_NAME = 'tmsource';
  var UTM_PARAMS = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content'];
  var COOKIE_NAME = 'tmsource';
  var COOKIE_EXPIRES_DAYS = 60;
  var LOCATION = window.location;
  var URL = LOCATION.href;
  var COOKIE_DOMAIN = LOCATION.hostname.replace(/^www\./, '');
  
  function getParameterByName(name) {
    var regex = new RegExp("[?&]" + name + "(=([^&#]*)|&|#|$)"),
        results = regex.exec(URL);
    if (!results) return null;
    if (!results[2]) return '';
    return decodeURIComponent(results[2].replace(/\+/g, " "));
  }

  function setCookie(value) {
    var date = new Date();
    date.setTime(date.getTime() + (COOKIE_EXPIRES_DAYS * 24 * 60 * 60 * 1000));
    document.cookie =
      COOKIE_NAME + "=" + encodeURIComponent(value) + ";" +
      "expires=" + date.toUTCString() + ";" +
      "domain=" + COOKIE_DOMAIN + ";";
  }

  var utmParams = [];
  UTM_PARAMS.forEach(param => {
    var param = getParameterByName(param);
    if (param) {
      utmParams.push(param);
    }
  });
  var cookieValue = utmParams.join('-');

  if (!cookieValue) {
    cookieValue = getParameterByName(TM_PARAM_NAME);
  }

  if (!cookieValue) {
    return;
  }

  setCookie(cookieValue);

}, 300))