--- /dev/null
+import { Subscriber } from '../Subscriber';
+import { Subscription } from '../Subscription';
+import { Observable } from '../Observable';
+import { Operator } from '../Operator';
+import { Subject } from '../Subject';
+import { OperatorFunction } from '../types';
+
+/* tslint:disable:max-line-length */
+export function groupBy<T, K>(keySelector: (value: T) => K): OperatorFunction<T, GroupedObservable<K, T>>;
+export function groupBy<T, K>(keySelector: (value: T) => K, elementSelector: void, durationSelector: (grouped: GroupedObservable<K, T>) => Observable<any>): OperatorFunction<T, GroupedObservable<K, T>>;
+export function groupBy<T, K, R>(keySelector: (value: T) => K, elementSelector?: (value: T) => R, durationSelector?: (grouped: GroupedObservable<K, R>) => Observable<any>): OperatorFunction<T, GroupedObservable<K, R>>;
+export function groupBy<T, K, R>(keySelector: (value: T) => K, elementSelector?: (value: T) => R, durationSelector?: (grouped: GroupedObservable<K, R>) => Observable<any>, subjectSelector?: () => Subject<R>): OperatorFunction<T, GroupedObservable<K, R>>;
+/* tslint:enable:max-line-length */
+
+/**
+ * Groups the items emitted by an Observable according to a specified criterion,
+ * and emits these grouped items as `GroupedObservables`, one
+ * {@link GroupedObservable} per group.
+ *
+ * 
+ *
+ * When the Observable emits an item, a key is computed for this item with the keySelector function.
+ *
+ * If a {@link GroupedObservable} for this key exists, this {@link GroupedObservable} emits. Elsewhere, a new
+ * {@link GroupedObservable} for this key is created and emits.
+ *
+ * A {@link GroupedObservable} represents values belonging to the same group represented by a common key. The common
+ * key is available as the key field of a {@link GroupedObservable} instance.
+ *
+ * The elements emitted by {@link GroupedObservable}s are by default the items emitted by the Observable, or elements
+ * returned by the elementSelector function.
+ *
+ * ## Examples
+ *
+ * ### Group objects by id and return as array
+ *
+ * ```ts
+ * import { of } from 'rxjs';
+ * import { mergeMap, groupBy, reduce } from 'rxjs/operators';
+ *
+ * of(
+ * {id: 1, name: 'JavaScript'},
+ * {id: 2, name: 'Parcel'},
+ * {id: 2, name: 'webpack'},
+ * {id: 1, name: 'TypeScript'},
+ * {id: 3, name: 'TSLint'}
+ * ).pipe(
+ * groupBy(p => p.id),
+ * mergeMap((group$) => group$.pipe(reduce((acc, cur) => [...acc, cur], []))),
+ * )
+ * .subscribe(p => console.log(p));
+ *
+ * // displays:
+ * // [ { id: 1, name: 'JavaScript'},
+ * // { id: 1, name: 'TypeScript'} ]
+ * //
+ * // [ { id: 2, name: 'Parcel'},
+ * // { id: 2, name: 'webpack'} ]
+ * //
+ * // [ { id: 3, name: 'TSLint'} ]
+ * ```
+ *
+ * ### Pivot data on the id field
+ *
+ * ```ts
+ * import { of } from 'rxjs';
+ * import { groupBy, map, mergeMap, reduce } from 'rxjs/operators';
+ *
+ * of(
+ * { id: 1, name: 'JavaScript' },
+ * { id: 2, name: 'Parcel' },
+ * { id: 2, name: 'webpack' },
+ * { id: 1, name: 'TypeScript' },
+ * { id: 3, name: 'TSLint' }
+ * )
+ * .pipe(
+ * groupBy(p => p.id, p => p.name),
+ * mergeMap(group$ =>
+ * group$.pipe(reduce((acc, cur) => [...acc, cur], [`${group$.key}`]))
+ * ),
+ * map(arr => ({ id: parseInt(arr[0], 10), values: arr.slice(1) }))
+ * )
+ * .subscribe(p => console.log(p));
+ *
+ * // displays:
+ * // { id: 1, values: [ 'JavaScript', 'TypeScript' ] }
+ * // { id: 2, values: [ 'Parcel', 'webpack' ] }
+ * // { id: 3, values: [ 'TSLint' ] }
+ * ```
+ *
+ * @param {function(value: T): K} keySelector A function that extracts the key
+ * for each item.
+ * @param {function(value: T): R} [elementSelector] A function that extracts the
+ * return element for each item.
+ * @param {function(grouped: GroupedObservable<K,R>): Observable<any>} [durationSelector]
+ * A function that returns an Observable to determine how long each group should
+ * exist.
+ * @return {Observable<GroupedObservable<K,R>>} An Observable that emits
+ * GroupedObservables, each of which corresponds to a unique key value and each
+ * of which emits those items from the source Observable that share that key
+ * value.
+ * @method groupBy
+ * @owner Observable
+ */
+export function groupBy<T, K, R>(keySelector: (value: T) => K,
+ elementSelector?: ((value: T) => R) | void,
+ durationSelector?: (grouped: GroupedObservable<K, R>) => Observable<any>,
+ subjectSelector?: () => Subject<R>): OperatorFunction<T, GroupedObservable<K, R>> {
+ return (source: Observable<T>) =>
+ source.lift(new GroupByOperator(keySelector, elementSelector, durationSelector, subjectSelector));
+}
+
+export interface RefCountSubscription {
+ count: number;
+ unsubscribe: () => void;
+ closed: boolean;
+ attemptedToUnsubscribe: boolean;
+}
+
+class GroupByOperator<T, K, R> implements Operator<T, GroupedObservable<K, R>> {
+ constructor(private keySelector: (value: T) => K,
+ private elementSelector?: ((value: T) => R) | void,
+ private durationSelector?: (grouped: GroupedObservable<K, R>) => Observable<any>,
+ private subjectSelector?: () => Subject<R>) {
+ }
+
+ call(subscriber: Subscriber<GroupedObservable<K, R>>, source: any): any {
+ return source.subscribe(new GroupBySubscriber(
+ subscriber, this.keySelector, this.elementSelector, this.durationSelector, this.subjectSelector
+ ));
+ }
+}
+
+/**
+ * We need this JSDoc comment for affecting ESDoc.
+ * @ignore
+ * @extends {Ignored}
+ */
+class GroupBySubscriber<T, K, R> extends Subscriber<T> implements RefCountSubscription {
+ private groups: Map<K, Subject<T | R>> = null;
+ public attemptedToUnsubscribe: boolean = false;
+ public count: number = 0;
+
+ constructor(destination: Subscriber<GroupedObservable<K, R>>,
+ private keySelector: (value: T) => K,
+ private elementSelector?: ((value: T) => R) | void,
+ private durationSelector?: (grouped: GroupedObservable<K, R>) => Observable<any>,
+ private subjectSelector?: () => Subject<R>) {
+ super(destination);
+ }
+
+ protected _next(value: T): void {
+ let key: K;
+ try {
+ key = this.keySelector(value);
+ } catch (err) {
+ this.error(err);
+ return;
+ }
+
+ this._group(value, key);
+ }
+
+ private _group(value: T, key: K) {
+ let groups = this.groups;
+
+ if (!groups) {
+ groups = this.groups = new Map<K, Subject<T | R>>();
+ }
+
+ let group = groups.get(key);
+
+ let element: R;
+ if (this.elementSelector) {
+ try {
+ element = this.elementSelector(value);
+ } catch (err) {
+ this.error(err);
+ }
+ } else {
+ element = <any>value;
+ }
+
+ if (!group) {
+ group = (this.subjectSelector ? this.subjectSelector() : new Subject<R>()) as Subject<T | R>;
+ groups.set(key, group);
+ const groupedObservable = new GroupedObservable(key, group, this);
+ this.destination.next(groupedObservable);
+ if (this.durationSelector) {
+ let duration: any;
+ try {
+ duration = this.durationSelector(new GroupedObservable<K, R>(key, <Subject<R>>group));
+ } catch (err) {
+ this.error(err);
+ return;
+ }
+ this.add(duration.subscribe(new GroupDurationSubscriber(key, group, this)));
+ }
+ }
+
+ if (!group.closed) {
+ group.next(element);
+ }
+ }
+
+ protected _error(err: any): void {
+ const groups = this.groups;
+ if (groups) {
+ groups.forEach((group, key) => {
+ group.error(err);
+ });
+
+ groups.clear();
+ }
+ this.destination.error(err);
+ }
+
+ protected _complete(): void {
+ const groups = this.groups;
+ if (groups) {
+ groups.forEach((group, key) => {
+ group.complete();
+ });
+
+ groups.clear();
+ }
+ this.destination.complete();
+ }
+
+ removeGroup(key: K): void {
+ this.groups.delete(key);
+ }
+
+ unsubscribe() {
+ if (!this.closed) {
+ this.attemptedToUnsubscribe = true;
+ if (this.count === 0) {
+ super.unsubscribe();
+ }
+ }
+ }
+}
+
+/**
+ * We need this JSDoc comment for affecting ESDoc.
+ * @ignore
+ * @extends {Ignored}
+ */
+class GroupDurationSubscriber<K, T> extends Subscriber<T> {
+ constructor(private key: K,
+ private group: Subject<T>,
+ private parent: GroupBySubscriber<any, K, T | any>) {
+ super(group);
+ }
+
+ protected _next(value: T): void {
+ this.complete();
+ }
+
+ /** @deprecated This is an internal implementation detail, do not use. */
+ _unsubscribe() {
+ const { parent, key } = this;
+ this.key = this.parent = null;
+ if (parent) {
+ parent.removeGroup(key);
+ }
+ }
+}
+
+/**
+ * An Observable representing values belonging to the same group represented by
+ * a common key. The values emitted by a GroupedObservable come from the source
+ * Observable. The common key is available as the field `key` on a
+ * GroupedObservable instance.
+ *
+ * @class GroupedObservable<K, T>
+ */
+export class GroupedObservable<K, T> extends Observable<T> {
+ /** @deprecated Do not construct this type. Internal use only */
+ constructor(public key: K,
+ private groupSubject: Subject<T>,
+ private refCountSubscription?: RefCountSubscription) {
+ super();
+ }
+
+ /** @deprecated This is an internal implementation detail, do not use. */
+ _subscribe(subscriber: Subscriber<T>) {
+ const subscription = new Subscription();
+ const { refCountSubscription, groupSubject } = this;
+ if (refCountSubscription && !refCountSubscription.closed) {
+ subscription.add(new InnerRefCountSubscription(refCountSubscription));
+ }
+ subscription.add(groupSubject.subscribe(subscriber));
+ return subscription;
+ }
+}
+
+/**
+ * We need this JSDoc comment for affecting ESDoc.
+ * @ignore
+ * @extends {Ignored}
+ */
+class InnerRefCountSubscription extends Subscription {
+ constructor(private parent: RefCountSubscription) {
+ super();
+ parent.count++;
+ }
+
+ unsubscribe() {
+ const parent = this.parent;
+ if (!parent.closed && !this.closed) {
+ super.unsubscribe();
+ parent.count -= 1;
+ if (parent.count === 0 && parent.attemptedToUnsubscribe) {
+ parent.unsubscribe();
+ }
+ }
+ }
+}
projects / dotfiles / .git / blobdiff