Google Analytics (analytics.js) get referral `ga_referrer`

ga_referrer-analytics.js

ga(function(tracker) {
    var ga_refferer = tracker.get('referrer'); // this get the referral from google analytics.js

    
    if (typeof wCookies != 'undefined' && typeof wCookies().get('ga_refferer') == 'undefined') {
        if (typeof ga_refferer != 'undefined') {
            wCookies().set('ga_refferer', ga_refferer, {expires: 30});
        } else {
            wCookies().set('ga_refferer', 'direct', {expires: 30});
        }
    }
});

// useed with 
// https://github.com/arturmamedov/withFront/blob/master/js/core/w-core.js // for clog() function that can be removed
//
// https://github.com/js-cookie/js-cookie
// https://github.com/arturmamedov/withFront/blob/master/js/core/w-cookie.js // for wCookies() function wrapper