backbone.js – “未捕获TypeError：undefined不是函数”初始化Backbone集合

我有一个Backbone集合,如下所示：

var FooCollection = Backbone.Collection.extend({
    model:Foo,initialize: function (attributes,options) {
        this.barId = options.barId;
    }
});

var Foo = Backbone.Model.extend({});

当我尝试初始化这个,我得到Backbone.Collection的_prepareModel()函数中的“未捕获TypeError：undefined不是一个函数”.

不好的电话是在model = new this.model(attrs,options)中.

// Prepare a model or hash of attributes to be added to this collection.
_prepareModel: function(model,options) {
  options || (options = {});
  if (!(model instanceof Model)) {
    var attrs = model;
    options.collection = this;
    model = new this.model(attrs,options); // <-- BLOWS UP HERE
    if (!model._validate(model.attributes,options)) model = false;
  } else if (!model.collection) {
    model.collection = this;
  }
  return model;
},

当我在调试器中通过_prepareModel()时,它看起来像这个时候的类型是child,而this.model实际上是未定义的.

有谁能告诉我我做错了什么？

解决方法

在我的实际代码中,Foo在FooCollection之后被声明.没有意识到Javascript不支持前向声明. [headdesk]