// script which reads UTM params from the URL and adds them to all links on the current page
$(document).ready(function() {
  var utms = ['medium', 'source', 'campaign', 'term', 'content'], utmStrings = [];
  var domain = ''; // add domain here, only links to given domain will be siffixed with utm params
  var domainRegexp = new RegExp(domain.replace(/\./g, '\\.'));
  utms.forEach(function(utm) {
    var match = window.location.search.match(new RegExp('utm_' + utm + '=([^&]+)'));
    if(match) {
      utmStrings.push('utm_' + utm + '=' + match[1]);
    }
  });
  if(utmStrings.length) {
    $('a').each(function() {
      var link = this.href, prefix, params = '';
      if(
        link.match(domainRegexp) &&
        !link.match(/[?&]utm_/)
      ) {
        prefix = link.match(/\?/) ? '&' : '?';
        this.href = link + prefix + utmStrings.join('&');
      }
    });
  }
});