Ember Model. Adding BelongsTo.

EM_belongsTo.js

App.Person = Ember.Model.extend({
  id: Ember.attr(),
  name: Ember.attr(),
  addresses: Ember.hasMany(App.Address, {key: 'addresses'})
});

App.Address = Ember.Model.extend({
  id: Ember.attr(),
  street: Ember.attr(),
  person_id: Ember.attr(),
  person: Ember.belongsTo(App.Person, {key: 'person_id'})
});

var myPerson = App.Person.create({id:1, name: 'Erik'});
myPerson.save();
var myAddress = myPerson.get('addresses');
myAddress.create({id:2, street: '6th Street', person_id: myPerson.get('id'), person: myPerson});
myAddress.save()