Observable `of` deprecated. What is the equivalent?

Question

In my case, I have an access token, and should that token exist, I would return it as an observable of type string:

if (this.accessToken){
  return of(this.accessToken);
}

Due to a recent update, I noticed that of is deprecated with the following message:

of is deprecated: use scheduled instead 'scheduled([a, b, c], scheduler)' (deprecation)

The new syntax is quite verbose, would anyone know the equivalent scheduled version of the same simple of? The keyword name makes it difficult to search for information on it.

Thanks!

Answer 1

Only the overloads that accept a scheduler are deprecated. The variant that you are using is not deprecated, see https://github.com/ReactiveX/rxjs/blob/master/src/internal/observable/of.ts

Answer 2

As said above, it is not deprecated.

I suppose you are migrating from RxJS v5 to RxJS v6. In that case:

The standard observable processing like of, map, filter, etc

Observable.of(1,2,3).map(x => 2 * x);

Becomes

import {of, map} from 'rxjs';
import {map} from 'rxjs/operators';

of(1,2,3).pipe(map(x => 2 * x));

Check more here https://www.learnrxjs.io/concepts/rxjs5-6.html

Answer 3

If you do have a scheduler, the equivalent for of(item, scheduler) is scheduled([item], scheduler). If you're already passing in an array of items, you don't need the brackets.

Answer 4

@daniel-hilgarth is right but you can use following commands if you need to emulate of(1, 2, 3)

import {asapScheduler, scheduled} from "rxjs";
scheduled([1, 2, 3], asapScheduler);

or

import {asyncScheduler, scheduled} from "rxjs";
scheduled([1, 2, 3], asyncScheduler);

You can read more about asap here: https://rxjs.dev/api/index/const/asapScheduler