I am having some problems implementing Google Tag Manager on my website. I have a Google code, and when I try it on my site, it makes a lot of javascript conflicts.
So I tried to put the code on a seperate file, in order to do it Step by Step and observe the behavior of the different scripts.
So here my very simple HTML page:
<!DOCTYPE html>
<html>
<head>
<title>Titre</title>
</head>
<body>
<!-- Google Tag Manager -->
<noscript>
<iframe src="http://www.googletagmanager.com/ns.html?id=GTM-XXXXXX" height="0" width="0" style="display:none;visibility:hidden"></iframe>
</noscript>
<script type="text/javascript">
dataLayer = [{'uid':'12'}];
(function(w,d,s,l,i){
w[l]=w[l]||[];
w[l].push({'gtm.start': new Date().getTime(),event:'gtm.js'});
var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';
j.async=true;
j.src='//www.googletagmanager.com/gtm.js?id='+i+dl;
f.parentNode.insertBefore(j,f);
})(window,document,'script','dataLayer','GTM-XXXXXX');
</script>
<!-- End Google Tag Manager -->
hello
</body>
</html>
And this very page, returns an error in the JS console:
Uncaught ReferenceError: jQuery is not defined
Well, this is unexpected, what does jQuery has to do here? I didn't even declare it on my body tag, is Google requiring jQuery?
So that was weird, and the second thing, when I look on my generated HTML page, after loading on a browser:
<body>
... Long stuff here
<script type="text/javascript" id="" src="//ajax.googleapis.com/ajax/libs/jquery/1.8.2/jquery.min.js"></script>
... some other stuff here
</body>
What kind of sorcery is this? Why does Google add a jquery thing at the bottom of my page, and why does my console shows me a jQuery error?
Thanks a lot for any kind of information, I am totally lost... And have a nice day!