Backviewでもdefault値を設定する例

backboneView.js

var baseView = Backbone.View.extend({
  defaults: {
    defaulsVal: 'this is defaults'
  },
  initialize: function () {
    _.defaults(this, this.defaults);
  },
  render: function () {
    console.log(this.defaulsVal);
  }
});

var view = new baseView();

view.render();