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- import { Observable } from './Observable';
- /**
- * Represents a push-based event or value that an {@link Observable} can emit.
- * This class is particularly useful for operators that manage notifications,
- * like {@link materialize}, {@link dematerialize}, {@link observeOn}, and
- * others. Besides wrapping the actual delivered value, it also annotates it
- * with metadata of, for instance, what type of push message it is (`next`,
- * `error`, or `complete`).
- *
- * @see {@link materialize}
- * @see {@link dematerialize}
- * @see {@link observeOn}
- *
- * @class Notification<T>
- */
- export class Notification {
- constructor(kind, value, error) {
- this.kind = kind;
- this.value = value;
- this.error = error;
- this.hasValue = kind === 'N';
- }
- /**
- * Delivers to the given `observer` the value wrapped by this Notification.
- * @param {Observer} observer
- * @return
- */
- observe(observer) {
- switch (this.kind) {
- case 'N':
- return observer.next && observer.next(this.value);
- case 'E':
- return observer.error && observer.error(this.error);
- case 'C':
- return observer.complete && observer.complete();
- }
- }
- /**
- * Given some {@link Observer} callbacks, deliver the value represented by the
- * current Notification to the correctly corresponding callback.
- * @param {function(value: T): void} next An Observer `next` callback.
- * @param {function(err: any): void} [error] An Observer `error` callback.
- * @param {function(): void} [complete] An Observer `complete` callback.
- * @return {any}
- */
- do(next, error, complete) {
- const kind = this.kind;
- switch (kind) {
- case 'N':
- return next && next(this.value);
- case 'E':
- return error && error(this.error);
- case 'C':
- return complete && complete();
- }
- }
- /**
- * Takes an Observer or its individual callback functions, and calls `observe`
- * or `do` methods accordingly.
- * @param {Observer|function(value: T): void} nextOrObserver An Observer or
- * the `next` callback.
- * @param {function(err: any): void} [error] An Observer `error` callback.
- * @param {function(): void} [complete] An Observer `complete` callback.
- * @return {any}
- */
- accept(nextOrObserver, error, complete) {
- if (nextOrObserver && typeof nextOrObserver.next === 'function') {
- return this.observe(nextOrObserver);
- }
- else {
- return this.do(nextOrObserver, error, complete);
- }
- }
- /**
- * Returns a simple Observable that just delivers the notification represented
- * by this Notification instance.
- * @return {any}
- */
- toObservable() {
- const kind = this.kind;
- switch (kind) {
- case 'N':
- return Observable.of(this.value);
- case 'E':
- return Observable.throw(this.error);
- case 'C':
- return Observable.empty();
- }
- throw new Error('unexpected notification kind value');
- }
- /**
- * A shortcut to create a Notification instance of the type `next` from a
- * given value.
- * @param {T} value The `next` value.
- * @return {Notification<T>} The "next" Notification representing the
- * argument.
- */
- static createNext(value) {
- if (typeof value !== 'undefined') {
- return new Notification('N', value);
- }
- return Notification.undefinedValueNotification;
- }
- /**
- * A shortcut to create a Notification instance of the type `error` from a
- * given error.
- * @param {any} [err] The `error` error.
- * @return {Notification<T>} The "error" Notification representing the
- * argument.
- */
- static createError(err) {
- return new Notification('E', undefined, err);
- }
- /**
- * A shortcut to create a Notification instance of the type `complete`.
- * @return {Notification<any>} The valueless "complete" Notification.
- */
- static createComplete() {
- return Notification.completeNotification;
- }
- }
- Notification.completeNotification = new Notification('C');
- Notification.undefinedValueNotification = new Notification('N', undefined);
- //# sourceMappingURL=Notification.js.map
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