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- import { Notification } from '../Notification';
- import { OperatorFunction, ObservableNotification } from '../types';
- import { operate } from '../util/lift';
- import { createOperatorSubscriber } from './OperatorSubscriber';
- /**
- * Represents all of the notifications from the source Observable as `next`
- * emissions marked with their original types within {@link Notification}
- * objects.
- *
- * <span class="informal">Wraps `next`, `error` and `complete` emissions in
- * {@link Notification} objects, emitted as `next` on the output Observable.
- * </span>
- *
- * 
- *
- * `materialize` returns an Observable that emits a `next` notification for each
- * `next`, `error`, or `complete` emission of the source Observable. When the
- * source Observable emits `complete`, the output Observable will emit `next` as
- * a Notification of type "complete", and then it will emit `complete` as well.
- * When the source Observable emits `error`, the output will emit `next` as a
- * Notification of type "error", and then `complete`.
- *
- * This operator is useful for producing metadata of the source Observable, to
- * be consumed as `next` emissions. Use it in conjunction with
- * {@link dematerialize}.
- *
- * ## Example
- *
- * Convert a faulty Observable to an Observable of Notifications
- *
- * ```ts
- * import { of, materialize, map } from 'rxjs';
- *
- * const letters = of('a', 'b', 13, 'd');
- * const upperCase = letters.pipe(map((x: any) => x.toUpperCase()));
- * const materialized = upperCase.pipe(materialize());
- *
- * materialized.subscribe(x => console.log(x));
- *
- * // Results in the following:
- * // - Notification { kind: 'N', value: 'A', error: undefined, hasValue: true }
- * // - Notification { kind: 'N', value: 'B', error: undefined, hasValue: true }
- * // - Notification { kind: 'E', value: undefined, error: TypeError { message: x.toUpperCase is not a function }, hasValue: false }
- * ```
- *
- * @see {@link Notification}
- * @see {@link dematerialize}
- *
- * @return A function that returns an Observable that emits
- * {@link Notification} objects that wrap the original emissions from the
- * source Observable with metadata.
- */
- export function materialize<T>(): OperatorFunction<T, Notification<T> & ObservableNotification<T>> {
- return operate((source, subscriber) => {
- source.subscribe(
- createOperatorSubscriber(
- subscriber,
- (value) => {
- subscriber.next(Notification.createNext(value));
- },
- () => {
- subscriber.next(Notification.createComplete());
- subscriber.complete();
- },
- (err) => {
- subscriber.next(Notification.createError(err));
- subscriber.complete();
- }
- )
- );
- });
- }
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