rate

(function() {
            //str = 'My Name is %NAME% and my age is %AGE%.'
            //{"%NAME%":"Mike","%AGE%":"26","%EVENT%":"20"}
            function format(str, replacements) {
                var _replacements = {};
                for (var k in replacements) {
                    _replacements["%" + k + "%"] = replacements[k];
                }
                return str.replace(/%\w+%/g, function(all) {
                    return _replacements[all] || all;
                });
            }

            function padZero(num, len) {
                var s= String(num), c= '0';
                len= len || 2;
                while(s.length < len) s= c + s;
                return s;
            }

            function getISODate() {            
                var d = new Date();             
                return format("%DD%/%MM%/%YYYY%", { "DD": padZero(d.getDate()), "MM": padZero(d.getMonth() + 1), "YYYY": d.getFullYear() })
            }

            var kDefaultRate = 60;
            var keyForStorage = "btx_rate";
            var keyUpdatedAt = "btx_updated_at";
            var currentDate = (new Date()).setHours(0,0,0,0);
            var lastUpdateAt = parseInt(localStorage.getItem(keyUpdatedAt)) || 0;
            var currentRate = parseFloat(localStorage.getItem(keyForStorage)) || kDefaultRate;

            function requestActualRate() {                
                var yql = "https://query.yahooapis.com/v1/public/yql";
                var url_cbr = format("http://www.cbr.ru/scripts/XML_dynamic.asp?date_req1=%D%&date_req2=%D%&VAL_NM_RQ=R01235", {"D": getISODate()});                
                // noinspection SqlDialectInspection
                // noinspection SqlNoDataSourceInspection
                var query = format("select Record.Value from xml where url = '%U%'", {"U": url_cbr})

                var url = yql + "?q=" + encodeURIComponent(query) + "&format=json&env=store%3A%2F%2Fdatatables.org%2Falltableswithkeys";
                console.log(url);
                console.log(query);
                console.log(url_cbr);
                var XHR = ("onload" in new XMLHttpRequest()) ? XMLHttpRequest : XDomainRequest;
                var xhr = new XHR();
                xhr.open("GET", url, true);
                xhr.onload = function(){
                    try {
                        var json = JSON.parse(this.responseText);
                        var rateStr = ("" + json.query.results.ValCurs.Record.Value).replace(',', '.');
                        var rate = parseFloat(rateStr);
                        if (rate) {
                            localStorage.setItem(keyForStorage, rate);
                            localStorage.setItem(keyUpdatedAt, currentDate);
                            currentRate = rate;
                            broadcastChangeRate();
                        }
                    } catch (e) {
                        console.error(e);
                    }
                };
                xhr.send();
            }

            function broadcastChangeRate() {
                var items = document.querySelectorAll("*[data-price]");
                for (var i = 0, l = items.length; i < l; i++) {                    
                    var base = parseFloat(items[i].getAttribute("data-price")) || 1;                    
                    var price = base * currentRate;
                    var prefix = items[i].getAttribute("data-currency-prefix") || "";
                    var suffix = items[i].getAttribute("data-currency-suffix") || "";                    
                    items[i].innerHTML = format("%prefix%%price%%suffix%", { "price": price, "suffix": suffix, "prefix": prefix});    
                }                
            }
        
            function ready() {
                if (currentDate > lastUpdateAt) {
                    requestActualRate();
                }

                broadcastChangeRate();
            }

            document.addEventListener("DOMContentLoaded", ready);        
        }());