the function that is called when the Observable is
initially subscribed to. This function is given a Subscriber, to which new values
can be nexted, or an error method can be called to raise an error, or
complete can be called to notify of a successful completion.
Creates a new Observable by calling the Observable constructor
a new observable
Used as a NON-CANCELLABLE means of subscribing to an observable, for use with
APIs that expect promises, like async/await. You cannot unsubscribe from this.
WARNING: Only use this with observables you know will complete. If the source observable does not complete, you will end up with a promise that is hung up, and potentially all of the state of an async function hanging out in memory. To avoid this situation, look into adding something like timeout, {@link take}, {@link takeWhile}, or {@link takeUntil} amongst others.
import { interval, take } from 'rxjs';
const source$ = interval(1000).pipe(take(4));
async function getTotal() {
let total = 0;
await source$.forEach(value => {
total += value;
console.log('observable -> ' + value);
});
return total;
}
getTotal().then(
total => console.log('Total: ' + total)
);
// Expected:
// 'observable -> 0'
// 'observable -> 1'
// 'observable -> 2'
// 'observable -> 3'
// 'Total: 6'
a handler for each value emitted by the observable
a promise that either resolves on observable completion or rejects with the handled error
a handler for each value emitted by the observable
a constructor function used to instantiate the Promise
a promise that either resolves on observable completion or rejects with the handled error
Creates a new Observable, with this Observable instance as the source, and the passed operator defined as the new observable's operator.
the operator defining the operation to take on the observable
a new observable with the Operator applied
A representation of any set of values over any amount of time. This is the most basic building block of RxJS.