javascript - Race Condition of Backbone.Collection fetch -

i'm generating date list in selected month every date, make backbone.collection fetch.

here how loop every single date in month

for (var = 1; <= numofdays; i++) {    var d = < 10 ? '0'+i:i;    var v = new view({       dt: this.year + this.month + (d),       param: this.array    });          this.$el.append(v.render().el); } 

as can see above, each view (backbone.view) represent date , param object. loop param object using underscorejs _.each method upon callin render()

_.each(this.param, this.reading, this); 

and later initiate new object of backbone.collection , perform fetch right away.

reading: function (value, key) {    var _this = this;    this.fetchdata(new data.collection(), '/api/ + value.ipid').done(function(coll) {       var input = $('<input>').val(value.ipid).attr('data-inid', coll.first().get('in_id'));       _this.$el.append(input);    }); } 

i separate function this.fetchdata this

fetchdata: function (obj, url) {     var deferred = $.deferred(),         collection = obj;                collection.url = url;     var xhr = collection.fetch().done(function(data, textstatus, jqxhr) {         deferred.resolve(collection, data, textstatus, jqxhr);     }).fail(deferred.reject);     var promise = deferred.promise();     promise.abort = _.bind(xhr.abort, xhr);     return promise;      } 

unfortunately, each view, order of item inside param object shift because depends on race condition of backbone.ajax. let see items of param object

[{ipid: 44, measure: "cumec"},{ipid: 45, measure: "meter"},{ipid: 46, measure: "milimeter"}{ipid: 47, measure: "cumec"}] 

the object items in proper order. 44, 45, 46 , 47. listing pass change after fetch operation.

how tell backbonejs or underscorejs wait every fetch operation complete before start looping item inside param object

i want loop (_.each) wait fetch operation complete before continue looping

hope can enlighten way achieve this. thank , have day

if create , append dom element @ view creation time (i.e. inside reading function), reference inside done callback, elements in same order inside param array.

side note: can instantiate collection url directly, , there no need wrap jquery promise around promise returned fetch.