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- /** PURE_IMPORTS_START .._Subscriber,.._util_EmptyError PURE_IMPORTS_END */
- var __extends = (this && this.__extends) || function (d, b) {
- for (var p in b)
- if (b.hasOwnProperty(p))
- d[p] = b[p];
- function __() { this.constructor = d; }
- d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
- };
- import { Subscriber } from '../Subscriber';
- import { EmptyError } from '../util/EmptyError';
- /* tslint:enable:max-line-length */
- /**
- * Returns an Observable that emits only the last item emitted by the source Observable.
- * It optionally takes a predicate function as a parameter, in which case, rather than emitting
- * the last item from the source Observable, the resulting Observable will emit the last item
- * from the source Observable that satisfies the predicate.
- *
- * <img src="./img/last.png" width="100%">
- *
- * @throws {EmptyError} Delivers an EmptyError to the Observer's `error`
- * callback if the Observable completes before any `next` notification was sent.
- * @param {function} predicate - The condition any source emitted item has to satisfy.
- * @return {Observable} An Observable that emits only the last item satisfying the given condition
- * from the source, or an NoSuchElementException if no such items are emitted.
- * @throws - Throws if no items that match the predicate are emitted by the source Observable.
- * @method last
- * @owner Observable
- */
- export function last(predicate, resultSelector, defaultValue) {
- return function (source) { return source.lift(new LastOperator(predicate, resultSelector, defaultValue, source)); };
- }
- var LastOperator = /*@__PURE__*/ (/*@__PURE__*/ function () {
- function LastOperator(predicate, resultSelector, defaultValue, source) {
- this.predicate = predicate;
- this.resultSelector = resultSelector;
- this.defaultValue = defaultValue;
- this.source = source;
- }
- LastOperator.prototype.call = function (observer, source) {
- return source.subscribe(new LastSubscriber(observer, this.predicate, this.resultSelector, this.defaultValue, this.source));
- };
- return LastOperator;
- }());
- /**
- * We need this JSDoc comment for affecting ESDoc.
- * @ignore
- * @extends {Ignored}
- */
- var LastSubscriber = /*@__PURE__*/ (/*@__PURE__*/ function (_super) {
- __extends(LastSubscriber, _super);
- function LastSubscriber(destination, predicate, resultSelector, defaultValue, source) {
- _super.call(this, destination);
- this.predicate = predicate;
- this.resultSelector = resultSelector;
- this.defaultValue = defaultValue;
- this.source = source;
- this.hasValue = false;
- this.index = 0;
- if (typeof defaultValue !== 'undefined') {
- this.lastValue = defaultValue;
- this.hasValue = true;
- }
- }
- LastSubscriber.prototype._next = function (value) {
- var index = this.index++;
- if (this.predicate) {
- this._tryPredicate(value, index);
- }
- else {
- if (this.resultSelector) {
- this._tryResultSelector(value, index);
- return;
- }
- this.lastValue = value;
- this.hasValue = true;
- }
- };
- LastSubscriber.prototype._tryPredicate = function (value, index) {
- var result;
- try {
- result = this.predicate(value, index, this.source);
- }
- catch (err) {
- this.destination.error(err);
- return;
- }
- if (result) {
- if (this.resultSelector) {
- this._tryResultSelector(value, index);
- return;
- }
- this.lastValue = value;
- this.hasValue = true;
- }
- };
- LastSubscriber.prototype._tryResultSelector = function (value, index) {
- var result;
- try {
- result = this.resultSelector(value, index);
- }
- catch (err) {
- this.destination.error(err);
- return;
- }
- this.lastValue = result;
- this.hasValue = true;
- };
- LastSubscriber.prototype._complete = function () {
- var destination = this.destination;
- if (this.hasValue) {
- destination.next(this.lastValue);
- destination.complete();
- }
- else {
- destination.error(new EmptyError);
- }
- };
- return LastSubscriber;
- }(Subscriber));
- //# sourceMappingURL=last.js.map
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