Create dataLayer custom event for external clicks - google-analytics

Question

I am looking to create a dataLayer push event for any time a click is made on any external link - I plan to use it as a trigger to fire a GTM tag for external link tracking. I envision it will be something like this :
<script>
Some code to detect clicks on any external links
dataLayer.push({'event': 'eventNameXYZ'});
</script

Answer 1

An example function:
function pushToDataLayer() {
var links = document.getElementsByTagName('a');
for(var i=0,cnt=links.length;i<cnt;i++) {
var current = links[i];
current.onclick = function() {
dataLayer.push({
'href': current.href,
'event': 'outbound' // event to trigger a rule in the tag manager
});
}
}
}
(This will be much easier if you use jQuery or something like it). This will attach an click event to all links. The click will push an event and a variable with the clicked href to the dataLayer.
In the Tag Manager you need to create a new rule that triggers a tag on the custom event "outbound" and a Macro with the type dataLayer that catches the "href" dataLayer Variable. You can use this variable in your tags - for example with a GA virtual ´pageview - and have the tags fire with the rule "fire on event "outbound".
The code might not work on all browsers and is a demonstration of a principle rather than production code (plus it will catch all links, you'd need to test for absolute urls or domains name or css class names that suggest an outbound link). I would recommend using jQuery for finding the links and attaching events.