ember-router

Router.map(function() {
  this.route('emulate', { path: '/emulate' }, function() {
      this.route('show', { path: '/:my_model_id' });
  });
});

export default Ember.Route.extend({
    model: function(params) {
        if (params.my_model_id) {
            return this.store.find("my-model", params.my_model_id);
        } else {
            return this.store.createRecord("my-model");
        }
    }
});