Collection inside Model

Collection-inside-Model

var Document = Backbone.Model.extend({
  constructor: function() {
    this.items = new ItemSet(null, {document: this});
    this.items.on('change', this.save, this);
    Backbone.Model.apply(this, arguments);
  },
  parse: function(resp) {
    this.items.set(resp.items, {parse: true, remove: false});
    delete resp.items;
    return resp;
  },
  toJSON: function() {
    var attrs = _.clone(this.attributes);
    attrs.items = this.items.toJSON();
    return attrs;
  }
});
var ItemSet = Backbone.Collection.extend({
  model: Item,
  initialize: function(models, options) {
    this.document = options.document;
  }
});
var Item = Backbone.Model.extend({
  // access document with this.collection.document
});
var document1 = new Document({
  name: "Test",
  version: 1,
  items: [
    {name : "Item 1", position : 0},
    {name : "Item 2", position : 1}
  ]
});