n2_routing_wtf.js

{
  ngOnInit: function() {
    var self = this;
    this.sub = this.route.params.subscribe(function(params) {
      var id = +params['id'];
      self.heroService.getHero(id).then(function(hero) { 
        self.hero = hero
      });
    });
  },
  ngOnDestroy: function() {
    this.sub.unsubscribe();
  }
}
/*

I mean, I get why it works this way at a micro level, because it's all callbacks and
promises and more callbacks, but yikes does this seem fragile, fussy, and easy to get wrong/difficult to test.

 */