Dmitriy Mozgovoy

если неправильно указан DOM-элемент, как это узнать

$('#content').on('click' ,'#singleclick', function () {
debugger;
var product = $(this).parents('.product-block');
$('#product_name').val(product.find('.product-action .name a').text());
$('#product_price').val(product.find('.product-action .price').text());
$('#singleclick_title').text(product.find('.product-action .name a').text());
});

/**
        *
        * @param duration - продолжительность работы таймера
        * @param interval - время тика таймера
        * @param from     - начальное значение
        * @param to       - конечное значение
        * @param minStep  - минимальный шаг вызова callback
        * @param callback - обработчик
        */

       function timer(duration,interval,from,to,minStep,callback){
           var value=from,
               forward=(from<to),
               range=Math.abs(to-from),
               steps=duration/interval,
               step=range/steps,
               last=from,

               handle=setInterval(function(){
                   value+=step*(forward?1:-1);

                   if(forward?value>to:value<to){
                       value=to;
                       clearInterval(handle);
                       handle=null;
                   }

                   if(!minStep||!handle||Math.abs(last-value)>=minStep){
                       last=value;
                       callback(value,from,to);
                   }
               }
           ,interval);
           
           return handle;
       }


       timer(800,20,50,0,1,function(value){
           console.warn(Math.floor(value));
       })

var test=function(){

           this.enable = false;

           this.protectedFunc1=function(){
                console.warn('Protected func1 called!');
           }

           this.protectMethod=function(fn){
               var self=this,
                   fn;

               if(typeof fn!=='function'){
                   throw TypeError('Given thing is not a function!');
               }


               return function(){

                   console.log(self.enable);

                   if(!self.enable){
                       throw Error('Access to protected method not allowed');
                   }

                   return fn.apply(self,arguments);
               };
           }

           this.protectedFunc1=this.protectMethod(this.protectedFunc1);

           this.protectedFunc2=this.protectMethod(function(args){
               console.warn('Protected func1 called!');
           })


       }


       var obj=new test;

       obj.enable=true;
       obj.protectedFunc1(); //Protected func1 called!

       obj.enable=false;
       obj.protectedFunc1();// Error: Access to protected method not allowed

function getData(url, callback) {
           var RESPONSES = {
               '/countries': [
                   {name: 'Cameroon', continent: 'Africa'},
                   {name :'Fiji Islands', continent: 'Oceania'},
                   {name: 'Guatemala', continent: 'North America'},
                   {name: 'Japan', continent: 'Asia'},
                   {name: 'Yugoslavia', continent: 'Europe'},
                   {name: 'Tanzania', continent: 'Africa'}
               ],
               '/cities': [
                   {name: 'Bamenda', country: 'Cameroon'},
                   {name: 'Suva', country: 'Fiji Islands'},
                   {name: 'Quetzaltenango', country: 'Guatemala'},
                   {name: 'Osaka', country: 'Japan'},
                   {name: 'Subotica', country: 'Yugoslavia'},
                   {name: 'Zanzibar', country: 'Tanzania'},
               ],
               '/populations': [
                   {count: 138000, name: 'Bamenda'},
                   {count: 77366, name: 'Suva'},
                   {count: 90801, name: 'Quetzaltenango'},
                   {count: 2595674, name: 'Osaka'},
                   {count: 100386, name: 'Subotica'},
                   {count: 157634, name: 'Zanzibar'}
               ]
           };

           setTimeout(function () {
               var result = RESPONSES[url];
               if (!result) {
                   return callback('Unknown url');
               }

               callback(null, result);
           }, Math.round(Math.random * 1000));
       }

       /**
        * Ваши изменения ниже
        */
       
       var requests = ['/countries', '/cities', '/populations'];
       var responses = {}; //, counter=0;

       for (var i = 0; i < 3; i++) {
           var _request = requests[i];

           var callback = function(request){
               return function (error, result) {

                   responses[request] = result;

                   var i, j;

                   if (Object.keys(responses).length == 3) { //or counter++==3
                       var c = [], cc = [], p = 0;

                       for (i = 0; i < responses['/countries'].length; i++) {
                           if (responses['/countries'][i].continent === 'Africa') {
                               c.push(responses['/countries'][i].name);
                           }
                       }

                       for (i = 0; i < responses['/cities'].length; i++) {
                           for (j = 0; j < c.length; j++) {
                               if (responses['/cities'][i].country === c[j]) {
                                   cc.push(responses['/cities'][i].name);
                               }
                           }
                       }

                       for (i = 0; i < responses['/populations'].length; i++) {
                           for (j = 0; j < cc.length; j++) {
                               if (responses['/populations'][i].name === cc[j]) {
                                   p += responses['/populations'][i].count;
                               }
                           }
                       }

                       console.log('Total population in African cities: ' + p);
                   }
               }
           }(_request);


           getData(_request, callback);
       }

var requests = ['/countries', '/cities', '/populations'];
       var responses = {};

       function load(request){
           return new Promise(function(resolve,reject){
               getData(request,function(error, result){
                    if(!error){
                        resolve(result);
                    }else{
                        reject (error);
                    }
               })
           });
       }

       function getPopulation(state){

           return Promise.all(requests.map(function(request){
               return load(request);
           })).then(function(data){
               //console.log(arguments);
               var countries=data[0],
                   cities=data[1],
                   populations=data[2],
                   result;

               console.log(countries,cities,populations);

               //calc here for state

               return result;

           },function(error){
               console.warn("Data error",error);
           });
       }

       getPopulation("Africa").then(console.log);