dashboard.js

  createdByUserName: Ember.computed(
    'userId',
    function() {
      this.store.findRecord('user', parseInt(this.get('userId'))).then((user) => {
        console.log("userId");
        console.log(this.get('userId'));
        console.log(user);
        console.log(user.get('firstname'));
        return user.get('firstname');
      });
    }
  )