Falcor object flatten to array for Angular 2

falcor-angular2-object-to-array.js

/**
 * I am new to falcor and it is under development
 * but I find that I keep needing to flatten
 * integer keyed objects into arrays so that I can
 * use them with Angular 2's NgFor directive.
 * 
 * Perhaps I just need to write an angular pipe
 * but I'm curious if there's a way to have falcor
 * output arrays instead of keyed objects.
 * 
 * I am using model.get so that I don't have to go
 * to the server multiple times on first load. It
 * works very well except for having to convert the 
 * keyed objects back into arrays.
 * 
 * Any idea of better ways to accomplish this or if
 * what I am doing is actually an antipattern?
 * 
 * Thanks!
 * 
 */

Rx.Observable.fromPromise(model.get(
  'showList[0..1].name',
  'showList[0..1].show[0..5].performer.name',
  'showList[0..1].show[0..5].performer.rating'
))
.pluck('json','showList') // Grab the path .json.showList
.map((x) => {
  return flatten(x);
})
.subscribe((data) => {
  // onNext value
  this.data = data;
  console.log(data);
}, (err) => {
  // onError
  this.errorMessage(err);
});

/**
 * Takes an object like:
 * 
 *  { 0: 'a', 1: 'b', 2: 'c' }
 * 
 * and outputs an array like:
 * 
 *  ['a', 'b', 'c']
 */
flatten(obj) {
  return Object.keys(obj).reduce(function(previous, current) {
    previous.push(obj[current]);
    return previous;
  }, []); 
}

Just a detail, you don't need to use Observable.fromPromise() ... get() give you an Observable already.
Anthony.