gistfile1.js

Marionette.CollectionView.extend({

  initialize: function(options) {
    this._initChildViewStorage();
    this.childView = this.childView || options.childView;
    this.createChildren(options);
    this._initialEvents();
  },

  createChildren: function(options) {
    this.collection.each(function(model) {
      var childViewOptions = typeof this.childViewOptions === 'function' ? this.childViewOptions(model, options) : {};

      var view = new this.childView(_.extend({
        el: options.selector(this.$el.selector, model.get('_id')),
        model: model
      }, childViewOptions));

      this.initializeChild(view);
    }, this);
  },

  initializeChild: function(view) {
    this.proxyChildEvents(view);
    this.children.add(view);

    if (view.onRender) {
      view.onRender();
    }
  }
});