Promise .all() with RxJS

Question

I\'m writing an app in Angular 2 and I want to execute several http requests and run a function on the responses.

In Angular 1, I would write something like $q

Answer 1

I'm learning RxJS and I was trying to do the same thing with RxJS v5

It seems like we don't have forkJoin on v5 anymore, so here's how I got it working (works with flatMap or mergeMap, which are aliases):

const callOne = value =>
    new window.Promise(resolve =>
        setTimeout(() => resolve(value + 10), 3000)
    );

const callTwo = value =>
    new window.Promise(resolve =>
        setTimeout(() => resolve(value + 20), 1000)
    );

Rx.Observable
    .of(2)
    .do(() => console.log('querying...'))
    .mergeMap(number =>
        Rx.Observable.zip(
            Rx.Observable.fromPromise(callOne(number)),
            Rx.Observable.fromPromise(callTwo(number))
        )
    ).concatAll()
    .subscribe(createSubscriber('promises in parallel'));