javascript Minimal Analytics Snippet

Posted 2021-05-03

(function (context, trackingId, options) {
    const history = context.history;
    const doc = document;
    const nav = navigator || {};
    const storage = localStorage;
    const encode = encodeURIComponent;
    const pushState = history.pushState;
    const typeException = 'exception';
    const generateId = () => Math.random().toString(36);
    const getId = () => {
        if (!storage.cid) {
            storage.cid = generateId()
        }
        return storage.cid;
    };
    const serialize = (obj) => {
        var str = [];
        for (var p in obj) {
            if (obj.hasOwnProperty(p)) {
                if(obj[p] !== undefined) {
                    str.push(encode(p) + "=" + encode(obj[p]));
                }
            }
        }
        return str.join("&");
    };
    const track = (
        type, 
        eventCategory, 
        eventAction, 
        eventLabel, 
        eventValue, 
        exceptionDescription, 
        exceptionFatal
    ) => {
        const url = 'https://www.google-analytics.com/collect';
        const data = serialize({
            v: '1',
            ds: 'web',
            aip: options.anonymizeIp ? 1 : undefined,
            tid: trackingId,
            cid: getId(),
            t: type || 'pageview',
            sd: options.colorDepth && screen.colorDepth ? `${screen.colorDepth}-bits` : undefined,
            dr: doc.referrer || undefined,
            dt: doc.title,
            dl: doc.location.origin + doc.location.pathname + doc.location.search,
            ul: options.language ? (nav.language || "").toLowerCase() : undefined,
            de: options.characterSet ? doc.characterSet : undefined,
            sr: options.screenSize ? `${(context.screen || {}).width}x${(context.screen || {}).height}` : undefined,
            vp: options.screenSize && context.visualViewport ? `${(context.visualViewport || {}).width}x${(context.visualViewport || {}).height}` : undefined,
            ec: eventCategory || undefined,
            ea: eventAction || undefined,
            el: eventLabel || undefined,
            ev: eventValue || undefined,
            exd: exceptionDescription || undefined,
            exf: typeof exceptionFatal !== 'undefined' && !!exceptionFatal === false ? 0 : undefined,
        });

        if(nav.sendBeacon) {
            nav.sendBeacon(url, data)
        } else {
            var xhr = new XMLHttpRequest();
            xhr.open("POST", url, true);
            xhr.send(data);
        }
    };
    const trackEvent = (category, action, label, value) => track('event', category, action, label, value);
    const trackException = (description, fatal) => track(typeException, null, null, null, null, description, fatal);
    history.pushState = function (state) {
        if (typeof history.onpushstate == "function") {
            history.onpushstate({ state: state });
        }
        setTimeout(track, options.delay || 10);
        return pushState.apply(history, arguments);
    }
    track();
    context.ma = {
        trackEvent,
        trackException
    }
})(window, "XX-XXXXXXXXX-X", {
    anonymizeIp: true,
    colorDepth: true,
    characterSet: true,
    screenSize: true,
    language: true
});