mirror of
https://github.com/biobulkbende/biobulkbende.org.git
synced 2024-12-26 13:05:24 +00:00
124 lines
4.3 KiB
JavaScript
124 lines
4.3 KiB
JavaScript
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
|