Backbone.Model.set override that bubbles change events

gistfile1.js

var ModelWithNesting = Backbone.Model.extend({
  
  /*
   * Backbone.Model.set() override that sniffs out child Backbone Models and bubbles up events.
   * Accepts the same parameters as Backbone.Model.set().
   */
  set: function (key, val, options) {
    var self = this,
        attrs;
    if (key == null) return this;

    if (typeof key === 'object') {
      attrs = key;
      options = val;
    } else {
      (attrs = {})[key] = val;
    }

    // Iterate through each new attribute:value pair
    _.each(attrs, function (val, attr) {
      var childModel,
          childName;

      // If new attribute is a Backbone Model, bubble up change events
      if (val instanceof Backbone.Model) {
        childName = attr;
        childModel = val;

        // Must listen to all events to capture property changes as well
        self.listenTo(childModel, 'all', function (childEvent) {
          var changePrefix = 'change',
              changeSuffix,
              eventArgs,
              event;

          // If I'm a change event, prefix my name and bubble up
          if (childEvent.indexOf(changePrefix) === 0) {

            // Capture property change
            if (childEvent.length > changePrefix.length) {
              changeSuffix = childEvent.substring(changePrefix.length + 1);
            }

            // Preserve original arguments and create new event
            eventArgs = Array.prototype.slice.call(arguments, 1);
            event = changePrefix + ':' + childName + (changeSuffix ? ':' + changeSuffix : '');

            // Bubble event
            self.trigger.apply(self, [event].concat(eventArgs));
          }
        });
      }
    });

    // Continue with Backbone default set behavior
    Backbone.Model.prototype.set.apply(this, arguments);
  },

  /*
   * Backbone.Model.get() override that assumes dot-notation naming for nested models.
   * Accepts the same parameters as Backbone.Model.get().
   */
  get: function (key) {
    var dotIndex,
        modelKey,
        modelAttribute,
        model;

    // If period appears within key, assume a nested model
    if ((dotIndex = key.indexOf('.')) >= 0) {

      // Parse up to the first period for the child model key
      modelKey = key.substring(0, dotIndex);

      // The model attribute is everything afterward, including deeper dot-references
      modelAttribute = key.substring(dotIndex + 1);

      // Get the child model, and if not a true Backbone.Model throw an exception
      model = this.get(modelKey);
      if (!(model instanceof Backbone.Model)) {
        throw new Error(modelKey + ' is not a Model');
      }

      // Return the requested attribute from child.  This will work recursively on deeper
      // references if descendant get() methods are also overridden.
      return model.get(modelAttribute);
    } else {

      // Perform normal Backbone.Model.get
      return Backbone.Model.prototype.get.apply(this, arguments);
    }
  }
});