Btukfyl

I've got some JS code that runs eventually - I've got no idea whats's wrong.
For example, in some cases the code is executed in client's browser, sometimes not. We have a server indicating if a client reached the server from browser. 2/15 of clients don't get the job done.

Here's the code example.

__zScriptInstalled = false;

function __zMainFunction(w,d){



var expire_time = 24*60*60;

var __zLink = 'https://tracker.com/track/4c72663c8c?';

__zLink += '&visitor_uuid=7815528f-5631-4c10-a8e4-5c0ade253e3b';

var __zWebsitehash = '4c72663c8c';

var click_padding = 2;

var clicks_limit = 1;





var __zSelector = "*";





function __zGetCookie(name, default_value=undefined) {

    name += '_' + __zWebsitehash;

    var matches = document.cookie.match(new RegExp(

      "(?:^|; )" + name.replace(/([.$?*|{}()[]\/+^])/g, '\$1') + "=([^;]*)"

    ))

    return matches ? decodeURIComponent(matches[1]) : default_value

}



function __zSetCookie(name, value, props) {

    name += '_' + __zWebsitehash;

    props = props || {}

    var exp = props.expires



    if (typeof exp == "number" && exp) {

        var d = new Date()

        d.setTime(d.getTime() + exp*1000)

        exp = props.expires = d

    }



    if(exp && exp.toUTCString) { props.expires = exp.toUTCString() }

    value = encodeURIComponent(value)

    var updatedCookie = name + "=" + value



    for(var propName in props){

        updatedCookie += "; " + propName

        var propValue = props[propName]

        if(propValue !== true){ updatedCookie += "=" + propValue }

    }

    document.cookie = updatedCookie

}



function __zDeleteCookie(name) {

    name += '_' + __zWebsitehash;

    __zSetCookie(name, null, { expires: -1 })



}



function clear_trigger(selector) {

    __zSetCookie('_source_clickunder', true, { expires: expire_time });

    if (selector) {

        document.querySelectorAll(selector).removeAttribute('onclick');

    }

}





function __zGetCORS(url, success) {

    var xhr = new XMLHttpRequest();

    xhr.open('GET', url);

    xhr.onload = success;

    xhr.send();

    return xhr;

}





var __zMainHandler = function(e=undefined, override=false) {

    if (__zScriptInstalled && !override){

        console.log('sciprt already installed');

        return;

    }

    var __corsOnSuccess = function(request){

        __zScriptInstalled = true;

        var response = request.currentTarget.response || request.target.responseText;

        var parsed = JSON.parse(response);

        if (! parsed.hasOwnProperty('_link')){

            return;

        }

        if (parsed.hasOwnProperty('success')){

            if (parsed.success != true)

            return;

        }

        else{

            return;

        }



        var today = __zGetCookie('_source_today', 0);

        var now = new Date();

        if (today == 0){

            today = now.getDate();

            __zSetCookie('_source_today', today);

        }

        else if (today != now.getDate()){

            today = now.getDate();

            __zSetCookie('_source_today', today);

            __zSetCookie('_source_click_count' , 0);

        }







            var eventHandler = function(e) {

                var current_click = parseInt(__zGetCookie('_source_click_count', 0));

                __zSetCookie('_source_click_count', current_click + 1);

                if (clicks_limit * click_padding > current_click){

                    if (current_click % click_padding == 0) {

                        e.stopPropagation();

                        e.preventDefault();



                        let queue = parseInt(__zGetCookie('_source_today_queue', 0))

                        __zSetCookie('_source_today_queue', queue + 1);

                        window.open(__zLink+'&queue=' + queue, '_blank');

                        window.focus();

                    }

                }

                return true;

            };

            function DOMEventInstaller(e=undefined){



                var elementsList = document.querySelectorAll(__zSelector);

                for (var i = 0; i != elementsList.length; i++){

                    elem = elementsList.item(i);

                    elem.addEventListener('click', eventHandler, true);

                };

            }

            DOMEventInstaller();

            document.body.addEventListener('DOMNodeInserted', function(e){

                DOMEventInstaller(e.target);

                e.target.addEventListener('click', eventHandler, true);

            });









    }





    var interval = setInterval(

        function(){

            if (__zScriptInstalled){

                clearInterval(interval);

            }

            __zGetCORS(__zLink+'&response_type=json', __corsOnSuccess);

        }, 

        1500

    );





    console.log('script installed');

};



__zMainHandler();

document.addEventListener('DOMContentLoaded', function(e){__zMainHandler(e);});

};

__zMainFunction(window, document);

Maybe there're kinds o extensions that block the script execution.

Almost all modern browsers have options to disable js .
e.g. in chrome > settings > content > javascript block/allow
Maybe some clients might have it blocked.
But by default its allowed by browsers.

Also most browsers have do not track option.

Hope it helps.