The below code is what Google recommends. I placed the code in my footer.php just before the </body> tag (near the bottom of the file) to defer call defer-loading.js and than load my self hosted analytics.js code (myga.js file).
This code says wait for the entire document to load, then load the external file "defer-loading.js"
<script type="text/javascript">
function downloadJSAtOnload() {
var element = document.createElement("script");
element.src = "/defer-loading.js";
document.body.appendChild(element);
}
if (window.addEventListener)
window.addEventListener("load", downloadJSAtOnload, false);
else if (window.attachEvent)
window.attachEvent("onload", downloadJSAtOnload);
else window.onload = downloadJSAtOnload;
</script>
In the defer-loading.js file i placed the following NEW Google Analytics Tracking Code - also called Universal Analytics: (i replaced my id number and domain name for this question)
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','http://mydomainname.com/myga.js','ga');
ga('create', 'Uxxx-xx-xxx', 'auto');
ga('set', 'anonymizeIp', true);
ga('send', 'pageview');
Additional note: To keep the myga.js (analytics.js) code updated i use a daily cron on my server. It downloads the analytics.js from Google and replaces the old one on my server. This part works fine. Here you can find the tutorial - How do we update the script
Unfortunately the NEW Google Universal Tracking Code in my defer-loading.js file does not track the visits!
To find the error i used the following OLD Google Analytics Tracking code in defer-loading.js and it works fine:
var _gaq = _gaq || [];
_gaq.push(['_setAccount', 'Uxxx-xx-xxx']);
_gaq.push(['_trackPageview']);
(function() {
var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true;
ga.src = ('https:' == document.location.protocol ? 'https://ssl' : 'http://www') + '.mydomainname.com/myga.js';
var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s);
})();
With firebug i realized that the following file (1px/1px) only loads with the OLD (working) Google Analytics Code version. The NEW Code does not load this file - but everything else seems ok.
http://www.google-analytics.com/r/__utm.gif?................
Any idea why the NEW Google Analytics Universal Tracking Code does not work?