custom REST adapter for ember-data that sends the authentication token in a header

authenticated_rest_adapter.js

App.AuthenticatedRESTAdapter = DS.RESTAdapter.extend({
  ajax: function(url, type, hash) {
    hash         = hash || {};
    hash.headers = hash.headers || {};
    hash.headers['X-AUTHENTICATION-TOKEN'] = this.authToken;
    return this._super(url, type, hash);
  }
});

After looking around a bit, it appears that the headers property is designed for this:

App.AuthenticatedRESTAdapter = DS.RESTAdapter.extend({
  headers: Ember.computed('session.authToken',  function () {
    return {
      'X-AUTHENTICATION-TOKEN': this.get('session.authToken')
    };
  });
});