rxjs-async-map

Map an observable using an async function with a configurable concurreny level, while preserving element order.

Installation

rxjs-async-map is available via npm or yarn:

npm i --save rxjs-async-map

yarn add rxjs-async-map

Usage

import { of } from 'rxjs/observable/of';
import { asyncMap } from 'rxjs-async-map';

const myPromise = val =>
  new Promise(resolve => setTimeout(() => resolve(`Result: ${val}`), Math.random() * 1000));

const source = of(1, 2, 3);

// Map over the observable using the async function, while running
// up to two promises concurrently.
//
// The order of elements is preserved, even if the promises resolve
// out-of-order.
const example = source.pipe(asyncMap(myPromise, /* concurrency: */ 2));

/*
  output:
  "Result: 1"
  "Result: 2"
  "Result: 3"
*/
const subscribe = example.subscribe(val => console.log(val));

License

MIT