WonderfulBackboneJS

example1.js

$(function() {
  // 1
  window.ShoppingItem = Backbone.Model.extend({
    constructor: function () {
      if (!this.collection) {
        this.collection = Products;
      }
    },

    defaults: {
      title: "Empty item..",
      state: "To buy"
    }
  });

  // 2
  window.ShoppingList = Backbone.Collection.extend({
    url: 'list/',
    model: ShoppingItem
  });

  // 3
  window.Products = new ShoppingList();
});

example2.js

var item = new window.ShoppingItem;
item.save(title: ‘Eggs’);
eggs.set(state: ‘Bought’);
eggs.destroy;

example3.js

window.ShoppingList = Backbone.Collection.extend({
    url: 'list/',
    model: Item,
    constructor: function ShoppingList() {
        Backbone.Collection.prototype.constructor.apply(this, arguments);
    },

    toobuy: function () {
        return this.filter(function (item) { return item.get('state') === 'To buy'; });
    }
});