Route#resolveModelLater & Route#asyncModelFor

resolve-model-later.js

App.PostRoute = Ember.Route.extend({
  model(params) {
    const promise = this.store.findRecord('post', params.id);
    this.resolveModelLater(promise);
  }
});

App.PostCommentsRoute = Ember.Route.extend({
  model(params, transition) {
    this.resolveModelLater(Ember.RSVP.hash({
      OP: this.asyncModelFor('post').then((post) => post.author),
      comments: this.store.findAll('comments', transition.params.post.id)
    }));
  }
]);