EmberJS auto loading inverse relations? - ember.js

Question

I have a model like:
var Survey = DS.Model.extend({
title: DS.attr('string'),
});
and:
var SurveySection = DS.Model.extend({
survey: DS.belongsTo('survey', {async:true}),
title: DS.attr('string'),
help_text: DS.attr('string'),
});
If i have a survey object, can I just do survey.get('survey_section') to get all the sections associated with a particular survey, because this isn't working? It doesn't even work if I add a survey_sections: DS.hasMany('survey_sections', {async:true}) to my survey model.
I should add that I'm using fixtures. When I release the app they'll still be used (ie so if the RESTAdapater would fix it, that's not a fix in my case):
Survey.reopenClass({
FIXTURES: [
{
"id": 1,
"title": "Favourite food"
},
{
"id": 2,
"title": "Sports"
}
]
});
and:
SurveySection.reopenClass({
FIXTURES: [
{
"help_text": "",
"id": 1,
"survey": 1,
"title": "Italian food"
},
{
"help_text": "",
"id": 2,
"survey": 1,
"title": "Team sports"
}, ...]});
Is the fixture adapter not able to retrieve related records in the reverse direction like this? If not, will I have to go the laborious route of manually getting the sections with survey=1, for example (laborious because I'll have to take this approach throughout my whole app with other models)?
Update
Specifically my failing code is (with survey 1):
this.get('survey').get('survey_sections').then(function(survey_sections) {
// survey_sections contains no objects, so objectAt(0) returns undefined.
survey_sections.objectAt(0).get('questions').then(function(questions) {
console.log('Set first question ID to ' + self.get('firstQuestionId'));
});
});
As the fixtures show there should be 2 SurveySection objects in survey_sections, but instead none are found.

Answer 1

I didn't want to do it, but I had to add the forward relation to the items in the Survey fixture, e.g.:
Survey.reopenClass({
FIXTURES: [
{
"id": 1,
"title": "Favourite food",
"survey_sections": [1, 2],
},
{
"id": 2,
"title": "Sports",
"survey_sections": [3],
}
]
});
and update the Survey model with:
survey_sections: DS.hasMany('survey_sections', {async:true})