JS to pass google analytics and/or campaign data to a particular page

aap_campaign_tracker.js

(function($){

// If ever a link to donate.aamaadmiparty.org is clicked, pass on 'aap_campaign_tracker' cookie value to the page.
$(document).ready(function() {

  // This script runs on every AAP page load and does the below stuff mentioned in comments
  var vals = {}, hash, flag_site_entry = false, flag_campaign_data_in_url = false;

  // Check if the referrer is non aamaadmiparty.org URL, if yes, set that as "starter source"
  if (document.referrer.indexOf("aamaadmiparty.org") < 0) {
    var flag_site_entry = true;
    if (document.referrer = '') {
      vals.utm_source = 'direct';
    } else {
      vals.utm_source = document.referrer;
    }
  }

  // If the URL has utm_ mentions in it, start collecting those values (replace "starter source" if utm_source is present)

  if (window.location.href.indexOf("utm_") >= 0) {
    var hashes = window.location.href.slice(window.location.href.indexOf('?') + 1).split('&');
    flag_campaign_data_in_url = true;
    for(var i = 0; i < hashes.length; i++)
    {
        hash = hashes[i].split('=');
        if (hash[0].indexOf('utm_source') >= 0 && hash[1] != '') {
          vals.utm_source = hash[1];
        }
        if (hash[0].indexOf('utm_medium') >= 0) {
          vals.utm_medium = hash[1];
        }
        if (hash[0].indexOf('utm_term') >=0 ) {
          vals.utm_term = hash[1];
        }
        if (hash[0].indexOf('utm_content') >=0 ) {
          vals.utm_content = hash[1];
        }
        if (hash[0].indexOf('utm_campaign') >=0 ) {
          vals.utm_campaign = hash[1];
        }
    }
  }

  // Save all the values in user cookie 'aap_campaign_tracker' creating it, or replacing it if it already exists (only if referrer or utm_ present)
  if (flag_site_entry == true || flag_campaign_data_in_url == true) {
    $.cookie('aap_campaign_tracker', vals.toSource());
  }


  // Add onClick _link to all <a> elements on page where href contains example-B.co.uk
  $("a[href*='donate.aamaadmiparty.org']").click(function() {
  var c = eval($.cookie('aap_campaign_tracker'));
  var link = $(this).attr('href') + '?utm_source='+ c.utm_source +'&utm_medium='+ c.utm_medium +'&utm_term='+ c.utm_term +'&utm_content='+ c.utm_content +'&utm_campaign=' + c.utm_campaign;
  window.location = link;
  return false;
  });
  
});

})(jQuery);