var items = [

  {id: 0, name: '1st', age: 40},

  {id: 1, name: '2nd', age: 50},

  {id: 2, name: '3rd', age: 60},

];

​

​

// order stored in cookie or localstorage ^^

var sorted = [2, 1, 0];

​

// our source collection

var collection = new Backbone.Collection(items);

​

var sortedCollection = _.map(sorted, function (id, item, original) {

  return collection.get(id);

});

​

var sortedIds = sortedCollection.map(function (item) { return item.id })

console.log(sortedIds);

​

// my interpretation of a view into this sorted collection

​

var View = Backbone.View.extend({

  initialize: function () {

    this.render();

  },

  render: function () {

    var ul = this.collection.reduce(function (parent, item){

      var li = document.createElement('li');

      li.innerHTML = item.get('name');

      parent.appendChild(li);

      return parent;

    }, document.createElement('ul'));

    document.body.appendChild(ul);

  }

});

​

​

var sortedCollectionView = new View({collection: sortedCollection});

​