Question

I have a situation which has to be simple to solve, I would guess. Surely people are using Backbone Relational with CoffeeScript out there…

Here’s a model I have:

class MyCompany.Models.Establishment extends Backbone.RelationalModel
  defaults:
    name: null

class MyCompany.Collections.EstablishmentsCollection extends Backbone.Collection
  model: MyCompany.Models.Establishment
  url: '/establishments'

I haven’t even added any relationships yet, just extended RelationalModel. Now through the console when I issue a destroy on an instance of the model it successfully destroys the model on the server, but when complete it fails with the trace:

Uncaught TypeError: Object #<Establishment> has no method 'getCollection'
    _.extend.unregister
    Backbone.Events.trigger
    Backbone.RelationalModel.Backbone.Model.extend.trigger
    _.extend.destroy.options.success
    jQuery.extend._Deferred.deferred.resolveWith
    done
    jQuery.ajaxTransport.send.callback

It’s dying in line 235 of backbone-relational.js 0.4.0 because “this” is the model, I guess, instead of whatever it’s supposed to be, and the model doesn’t have a method “getCollection”.

Any ideas what I’m doing wrong, or should I report a bug? For reference, here’s the Javascript coffee generates:

(function() {
  var __hasProp = Object.prototype.hasOwnProperty, __extends = function(child, parent) {
    for (var key in parent) { if (__hasProp.call(parent, key)) child[key] = parent[key]; }
    function ctor() { this.constructor = child; }
    ctor.prototype = parent.prototype;
    child.prototype = new ctor;
    child.__super__ = parent.prototype;
    return child;
  };
  MyCompany.Models.Establishment = (function() {
    __extends(Establishment, Backbone.RelationalModel);
    function Establishment() {
      Establishment.__super__.constructor.apply(this, arguments);
    }
    Establishment.prototype.defaults = {
      name: null
    };
    return Establishment;
  })();
  MyCompany.Collections.EstablishmentsCollection = (function() {
    __extends(EstablishmentsCollection, Backbone.Collection);
    function EstablishmentsCollection() {
      EstablishmentsCollection.__super__.constructor.apply(this, arguments);
    }
    EstablishmentsCollection.prototype.model = MyCompany.Models.Establishment;
    EstablishmentsCollection.prototype.url = '/establishments';
    return EstablishmentsCollection;
  })();
}).call(this);

Answer 1

You need to update the underlying Backbone.js version. Here’s why:

Your error comes from this having the wrong value when unregister is called. unregister is called in response to an event bound from register:

model.bind( 'destroy', this.unregister, this );

That third argument sets the context. But that feature was only added as recently as Backbone 0.5.2, as the changelog shows.