updated

app.js

var App = Ember.Application.create({
  rootElement: '#ember-app'
});

App.Store = DS.Store.extend();

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

DS.RESTAdapter.reopen({
  namespace: 'api'
});

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

App.ListingController = Ember.ArrayController.extend({

  sortProperties: ['id'],
  sortAscending: false,

  firstLoad: function(){
    return this.store.all('listing');
  }.property(),

  actions: {
    nextTwelve: function(){
      var offset = $('.ember-listing').length;
      this.store.find('listing', {count: 12, offset: 12});
    }
  }

});

App.ListingRoute = Ember.Route.extend({
  model: function() {
    return this.store.find('listing', {count: 12});
  },
  setupController: function(controller, model) {
    this._super(controller, model);
  },
});

App.Listing = DS.Model.extend({
  sid: DS.attr('string'),
  url: DS.attr('string'),
  image: DS.attr('string'),
  name: DS.attr('string'),
  address: DS.attr('string'),
  city: DS.attr('string'),
  state: DS.attr('string'),
  zip: DS.attr('string'),
  market: DS.attr('string')
});