How to load a collection of objects using an ajax request in a foreach loop?

Question

JavaScript

Hello, it is necessary to get a collection of objects from a remote service using api in a loop. I wrote a method in which a request is made in a cycle and adds what I received to the collection.
But in fact, requests are executed asynchronously, and in the collection, instead of Undefined objects

this.getDataForPlaces = function(addresses){
  var locationDescs = [];
  _.each(addresses, function(address){
    var promise = $.when(getLocationDesc(address)).done(function(data){
                             locationDescs.push(data);
                    });
  })

  return locationDescs;
};



var getLocationDesc = function(address){

      var parameters = [];
            
            var message = {
                'action' : 'http://api.yelp.com/v2/search',
                'method' : 'GET',
                'parameters' : parameters
            };

            OAuth.setTimestampAndNonce(message);
            OAuth.SignatureMethod.sign(message, accessor);

            var parameterMap = OAuth.getParameterMap(message.parameters);
            $.ajax({
                'url' : message.action,
                'cache': true,
                'method':message.method,
                'data' : parameterMap,
                'dataType' : 'jsonp',
                'jsonp' : 'callback',
                'success':function(data){
                	console.log(data);
                        return data;
                }
            });
  };

Answer 1

promises to help

this.getDataForPlaces = function(addresses){
   return Promise.all(Array.prototype.map.call(addresses, function(address) {
      return getLocationDesc(address);
   }));
};

function getLocationDesc(address) {
   return new Promise(function(resolve, reject) {
      var parameters = [];
            
            var message = {
                'action' : 'http://api.yelp.com/v2/search',
                'method' : 'GET',
                'parameters' : parameters
            };

            OAuth.setTimestampAndNonce(message);
            OAuth.SignatureMethod.sign(message, accessor);

            var parameterMap = OAuth.getParameterMap(message.parameters);
            $.ajax({
                url : message.action,
                cache : true,
                method : message.method,
                data : parameterMap,
                dataType : 'jsonp',
                jsonp : 'callback',
                success : resolve,
                error : reject
            });
   });
};

Only something tells me that you have an error in getLocationDesc, the address argument is not used in any way