// Get the category, action and label from the element and send it to GA. The action is optional, because mostly it will be a click event.
var trackClickEvent = function () {
var eventCategory = this.getAttribute("data-event-category");
var eventAction = this.getAttribute("data-event-action");
var eventLabel = this.getAttribute("data-event-label");
var eventValue = this.getAttribute("data-event-value");
ga('send', 'event', eventCategory, (eventAction != undefined && eventAction != '' ? eventAction : 'click'), eventLabel, eventValue);
};
// Find all of the elements on the page which have the class 'ga-event'
var elementsToTrack = document.getElementsByClassName("ga-event");
// Add an event listener to each of the elements you found
var elementsToTrackLength = elementsToTrack.length;
for (var i = 0; i < elementsToTrackLength; i++) {
elementsToTrack[i].addEventListener('click', trackClickEvent, false);
}