Event tracking with Google Analytics

analytics.js

var signupLinks = document.querySelectorAll('[data-signup]');
for (i = 0; i < signupLinks.length; i++) {
    signupLinks[i].addEventListener("click", function(event){
        event.preventDefault();
        var eventLabel = event.target.getAttribute('data-signup');
        var gaIsLoaded = window[window['GoogleAnalyticsObject'] || 'ga'];
        if (gaIsLoaded) {
            ga('send', 'event', {
                eventCategory: 'Signup',
                eventAction: 'click',
                eventLabel: eventLabel
            });
        }
        window.location = event.target.getAttribute('href');
    })
}