Track outbound links with Google Universal Analytics.js

track.js

<script type="text/javascript">
    function _gaLt(event) {

        /* If GA is blocked or not loaded, or not main|middle|touch click then don't track */
        if (!ga.hasOwnProperty("loaded") || ga.loaded != true || (event.which != 1 && event.which != 2)) {
            return;
        }

        var el = event.srcElement || event.target;

        /* Loop up the DOM tree through parent elements if clicked element is not a link (eg: an image inside a link) */
        while (el && (typeof el.tagName == 'undefined' || el.tagName.toLowerCase() != 'a' || !el.href)) {
            el = el.parentNode;
        }

        /* if a link with valid href has been clicked */
        if (el && el.href) {

            var link = el.href;

            /* Only if it is an external link */
            if (link.indexOf(location.host) == -1 && !link.match(/^javascript\:/i)) {

                /* Is actual target set and not _(self|parent|top)? */
                var target = (el.target && !el.target.match(/^_(self|parent|top)$/i)) ? el.target : false;

                /* Assume a target if Ctrl|shift|meta-click */
                if (event.ctrlKey || event.shiftKey || event.metaKey || event.which == 2) {
                    target = "_blank";
                }

                var hbrun = false; // tracker has not yet run

                /* HitCallback to open link in same window after tracker */
                var hitBack = function() {
                    /* run once only */
                    if (hbrun) return;
                    hbrun = true;
                    window.location.href = link;
                };

                if (target) { /* If target opens a new window then just track */
                    ga(
                        "send", "event", "Outgoing Links", link,
                        document.location.pathname + document.location.search
                    );
                } else { /* Prevent standard click, track then open */
                    event.preventDefault ? event.preventDefault() : event.returnValue = !1;
                    /* send event with callback */
                    ga(
                        "send", "event", "Outgoing Links", link,
                        document.location.pathname + document.location.search, {
                            "hitCallback": hitBack
                        }
                    );

                    /* Run hitCallback again if GA takes longer than 1 second */
                    setTimeout(hitBack, 1000);
                }
            }
        }
    }

    var _w = window;
    /* Use "click" if touchscreen device, else "mousedown" */
    var _gaLtEvt = ("ontouchstart" in _w) ? "click" : "mousedown";
    /* Attach the event to all clicks in the document after page has loaded */
    _w.addEventListener ? _w.addEventListener("load", function() {document.body.addEventListener(_gaLtEvt, _gaLt, !1)}, !1)
        : _w.attachEvent && _w.attachEvent("onload", function() {document.body.attachEvent("on" + _gaLtEvt, _gaLt)});
</script>