| /** 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'; |
| /** |
| * Returns an Observable that emits the single item emitted by the source Observable that matches a specified |
| * predicate, if that Observable emits one such item. If the source Observable emits more than one such item or no |
| * such items, notify of an IllegalArgumentException or NoSuchElementException respectively. |
| * |
| * <img src="./img/single.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 - A predicate function to evaluate items emitted by the source Observable. |
| * @return {Observable<T>} An Observable that emits the single item emitted by the source Observable that matches |
| * the predicate. |
| . |
| * @method single |
| * @owner Observable |
| */ |
| export function single(predicate) { |
| return function (source) { return source.lift(new SingleOperator(predicate, source)); }; |
| } |
| var SingleOperator = /*@__PURE__*/ (/*@__PURE__*/ function () { |
| function SingleOperator(predicate, source) { |
| this.predicate = predicate; |
| this.source = source; |
| } |
| SingleOperator.prototype.call = function (subscriber, source) { |
| return source.subscribe(new SingleSubscriber(subscriber, this.predicate, this.source)); |
| }; |
| return SingleOperator; |
| }()); |
| /** |
| * We need this JSDoc comment for affecting ESDoc. |
| * @ignore |
| * @extends {Ignored} |
| */ |
| var SingleSubscriber = /*@__PURE__*/ (/*@__PURE__*/ function (_super) { |
| __extends(SingleSubscriber, _super); |
| function SingleSubscriber(destination, predicate, source) { |
| _super.call(this, destination); |
| this.predicate = predicate; |
| this.source = source; |
| this.seenValue = false; |
| this.index = 0; |
| } |
| SingleSubscriber.prototype.applySingleValue = function (value) { |
| if (this.seenValue) { |
| this.destination.error('Sequence contains more than one element'); |
| } |
| else { |
| this.seenValue = true; |
| this.singleValue = value; |
| } |
| }; |
| SingleSubscriber.prototype._next = function (value) { |
| var index = this.index++; |
| if (this.predicate) { |
| this.tryNext(value, index); |
| } |
| else { |
| this.applySingleValue(value); |
| } |
| }; |
| SingleSubscriber.prototype.tryNext = function (value, index) { |
| try { |
| if (this.predicate(value, index, this.source)) { |
| this.applySingleValue(value); |
| } |
| } |
| catch (err) { |
| this.destination.error(err); |
| } |
| }; |
| SingleSubscriber.prototype._complete = function () { |
| var destination = this.destination; |
| if (this.index > 0) { |
| destination.next(this.seenValue ? this.singleValue : undefined); |
| destination.complete(); |
| } |
| else { |
| destination.error(new EmptyError); |
| } |
| }; |
| return SingleSubscriber; |
| }(Subscriber)); |
| //# sourceMappingURL=single.js.map |