Q:

do relations work in ember fixture adapter?

Not sure what I'm doing wrong here, just trying to get a one to many relation working with ember data, using fixture adapters. Here it is on jsbin: http://jsbin.com/ucanam/4716/edit?html,js,output
I don't see any output in the html from my {{each}} loop.
js:
App = Ember.Application.create({});

App.ApplicationAdapter = DS.FixtureAdapter.extend();

App.Post = DS.Model.extend({
  body: DS.attr('string'),
  topic: DS.belongsTo('topic')
});

App.Topic = DS.Model.extend({
  posts: DS.hasMany('post')
});

App.Topic.FIXTURES = [
  {
    id: 1,
    posts: [
      {
        id: 1,
        body: 'hey i am a post',
        topic_id: 1
      }
    ]
  }
];

App.Router.map(function() {
  this.resource('topics', { path: '/' });
});

html:
<!DOCTYPE html>
<html>
<head>
<meta charset=utf-8 />
<title>JS Bin</title>
  <script src="http://code.jquery.com/jquery-2.0.2.js"></script>
  <script src="http://builds.emberjs.com/handlebars-1.0.0.js"></script>
  <script src="http://builds.emberjs.com/ember-latest.js"></script>
    <script src="http://builds.emberjs.com/ember-data-latest.js"></script>

</head>
<body>
  <script type="text/x-handlebars" data-template-name="application">
    <h1>ember-latest jsbin</h1>
    {{outlet}}
  </script>
  <script type="text/x-handlebars" data-template-name="topics">
    <h2>Index Content:</h2>
    <ul>
      {{#each topic in topics}}
        <li>{{id}}</li>
        {{#each post in posts}}
          {{body}}
        {{/each}}
      {{/each}}
    </ul>
  </script>
</body>
</html>

A:

The Fixture Adapter doesn't support embedded relationships by default.  The easiest way to accomplish this is to set your relationships to be async and add them to the post's fixtures.
App.Post = DS.Model.extend({
  body: DS.attr('string'),
  topic: DS.belongsTo('topic', {async: true})
});

App.Topic = DS.Model.extend({
  posts: DS.hasMany('post', {async: true})
});

App.Topic.FIXTURES = [
  {
    id: 1,
    posts: [1]
  }
];

App.Post.FIXTURES = [
  {
    id: 1,
    body: 'hey i am a post',
    topic: 1
  }
];

Here's your jsbin with it setup, http://jsbin.com/ucanam/4718/edit

