Question

I have a post which has many comments, and I want to display the comments on the post page. This is a Rails 3 application and I have my comments’ URLs nested in the post’s URL, so it basically looks like /post/1/comments.

The problem is, I’m not really sure how should I create a backbone collection for this situation. Should I just pass the post_id to the javascript form the server and then do something like

var Comments = Backbone.Collection.extend({
  model: Comment,
  url: '/post/' + idFromSomewhereElse + '/comments'
});

or is there a better way to handle this? How should I handle this in case of multiple nesting, where I could have something like /forums/1/topics/3/replies.

Answer 1

One idea could be to delegate the root of the Comments.url to the Post parent model:

// code simplified and not tested
App.Post = Backbone.Model.extend({
  urlRoot: "/posts"
});

App.Comments = Backbone.Collection.extend({
  model: Comment,

  urlRoot: function(){
    return this.post.url + "/comments";
  },

  initialize: function( opts ){
    this.post = opts.post;
  }
});

I think this idea can scale also for more complicate relations like /forums/1/topics/3/replies. You just have to take care of mantain the relation from every Collection to its parent.