Promise.all behavior with RxJS Observables?

Question

In Angular 1.x I would sometimes need to make multiple http requests and do something with all the responses. I would throw all the promises in an array and cal

Answer 1

Update May 2019 using RxJs v6

Found the other answers useful, and wished to offer an example for the answer offered by Arnaud about zip usage.

Here is a snippet showing the equivalence between Promise.all and the rxjs zip (note also, in rxjs6 how zip now gets imported using "rxjs" & not as an operator).

import { zip } from "rxjs";

const the_weather = new Promise(resolve => {
  setTimeout(() => {
    resolve({ temp: 29, conditions: "Sunny with Clouds" });
  }, 2000);
});

const the_tweets = new Promise(resolve => {
  setTimeout(() => {
    resolve(["I like cake", "BBQ is good too!"]);
  }, 500);
});

// Using RxJs
let source$ = zip(the_weather, the_tweets);
source$.subscribe(([weatherInfo, tweetInfo]) =>
  console.log(weatherInfo, tweetInfo)
);

// Using ES6 Promises
Promise.all([the_weather, the_tweets]).then(responses => {
  const [weatherInfo, tweetInfo] = responses;
  console.log(weatherInfo, tweetInfo);
});

The output from both are the same. Running the above gives:

{ temp: 29, conditions: 'Sunny with Clouds' } [ 'I like cake', 'BBQ is good too!' ]
{ temp: 29, conditions: 'Sunny with Clouds' } [ 'I like cake', 'BBQ is good too!' ]