Error destroying Backbone Relational model generated with Coffeescript - coffeescript

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.