rails backbone.js uncaught type error

Question

In my Followers collection inside my backbone app i have the following

    window.Curate.Collections.Following = Backbone.Collection.extend({
        model: Curate.Models.User,

      initialize: function (models, options) {
        this.add(models);
        this.user_id = options.user_id;
      },

      url: function () {
        return '/api/users/' + this.user_id + '/following';
      },

      parse: function(response){
            this.page_number = parseInt(response.page_number);
        this.total_pages = parseInt(response.total_pages);
            return response.users;
      }
    });

    window.Curate.Collections.following = new Curate.Collections.Following();
    Curate.Collections.following.fetch({
      data: { page: 1 }
    });

whats confusing me is that inside the initialize object the user_id in options.user_id is throwing an error

     Uncaught TypeError: Cannot read property 'user_id' of undefined

now this does what i want it to do which is to get the user_id so i can put it into the api url but this error occurs which in return wont allow me to push to heroku.

Any idea of what going on here? Thanks

Answer 1

The problem is that you didn't pass any arguments to your collection, actually you don't pass any options object

new Curate.Collections.Following();

It should be something like this and includes options object with user_id

new Curate.Collections.Following([{}, {}], { user_id: 123 });

P.S. this line inside initialize method of Backbone.Collection is not necessary

this.add(models);

because Backbone automatically resets collection with passed in array of models in constructor after initialize.