RxJS - Multiple sources for .withLatestFrom

Question

I want to merge the latest emitted values from multiple Observables, so right now I'm using .withLatestFrom. Except, it nests the data together in nested arrays instead of pushing the data into a new array value. Example code below.

Any ideas on how I can retrieve multiple Observable emits using .withLatestFrom?

source0
  .withLatestFrom(source1)
  .withLatestFrom(source2)
  .withLatestFrom(source3)
  .map((data) => { console.log(data) });

Solution 1

withLatestFrom supports multiple observables:

.withLatestFrom(source1, source2, source3)
.map((data) => { console.log(data) });

-> [val, value1, value2, value3]

It also supports function as it's last parameter, so you can get values other than arrays:

observable$
    .withLatestFrom(source1, source2, (val, one, two) => {
        return {val: val, one: one, two: two};
     });

Solution 2

withLatestFrom accepts multiple observables. so you can write it like:

let obs1$ = Rx.Observable.of('a');
let obs2$ = Rx.Observable.of('b');

Rx.Observable.interval(1000)
  .withLatestFrom(obs1$, obs2$)
  .subscribe(x=>console.log(x))

Comments

[aruno]

You can wrap the {} with () then you don't need an explicit return statement : .withLatestFrom(source1, source2, (val, one, two) => ({ val: val, one: one, two: two }));

[Eliya Cohen]

I was going to upvote this answer, but turns out I already upvoted it