GA and GTM

cleanup.html

<!--
  Add this as a custom html tag with a rule, that fires on all custom events. E.g.:
  
  {{event}} matches RegEx .+
-->
<script id="gtm-tag">
    (function() {
        // Find and remove all gtm event tags
        var gtmTags = document.querySelectorAll("#gtm-tag");
        Array.prototype.forEach.call(gtmTags, function(tag) {
            if (tag.parentNode) {
                tag.parentNode.removeChild(tag);
            }
        });
    })();
</script>

load-ga.html

<!--
  Add this as a custom html tag with the 'All pages' rule. Replace 'UA-XXXX-Y' with the Univeral Analytics Tracking-ID
-->
<script>
    (function() {
        // RFC4122-compliant uuid generator
        function uuid() {
            return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, function(c) {
                var r = Math.random()*16|0, v = c == 'x' ? r : (r&0x3|0x8);
                return v.toString(16);
            });
        }

        // Load google analytics code
        (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','assets/ga.js','ga');

        // Fetch or generate client id
        var supportsLocalStorage = typeof localStorage !== "undefined",
            clientId = supportsLocalStorage && localStorage.getItem("ga-clientid") || uuid();   
        if (supportsLocalStorage) {
            localStorage.setItem("ga-clientid", clientId);
        }

        // Initialize GA
        ga('create', 'UA-XXXX-Y', 'auto', {
            storage: "none",
            clientId: clientId
        });
    })()
</script>

send-event.html

<!--
    Use this tag to actually send the event.
-->
<script id="gtm-tag">
    // Send GA event
    ga("send", "event", "Event Category", "{{event}}");
</script>