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132 lines
5.1 KiB
132 lines
5.1 KiB
"use strict"; |
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var __extends = (this && this.__extends) || function (d, b) { |
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for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p]; |
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function __() { this.constructor = d; } |
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d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __()); |
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}; |
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var OuterSubscriber_1 = require('../OuterSubscriber'); |
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var subscribeToResult_1 = require('../util/subscribeToResult'); |
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/* tslint:enable:max-line-length */ |
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/** |
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* Combines the source Observable with other Observables to create an Observable |
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* whose values are calculated from the latest values of each, only when the |
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* source emits. |
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* |
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* <span class="informal">Whenever the source Observable emits a value, it |
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* computes a formula using that value plus the latest values from other input |
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* Observables, then emits the output of that formula.</span> |
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* |
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* <img src="./img/withLatestFrom.png" width="100%"> |
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* |
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* `withLatestFrom` combines each value from the source Observable (the |
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* instance) with the latest values from the other input Observables only when |
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* the source emits a value, optionally using a `project` function to determine |
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* the value to be emitted on the output Observable. All input Observables must |
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* emit at least one value before the output Observable will emit a value. |
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* |
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* @example <caption>On every click event, emit an array with the latest timer event plus the click event</caption> |
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* var clicks = Rx.Observable.fromEvent(document, 'click'); |
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* var timer = Rx.Observable.interval(1000); |
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* var result = clicks.withLatestFrom(timer); |
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* result.subscribe(x => console.log(x)); |
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* |
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* @see {@link combineLatest} |
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* |
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* @param {ObservableInput} other An input Observable to combine with the source |
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* Observable. More than one input Observables may be given as argument. |
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* @param {Function} [project] Projection function for combining values |
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* together. Receives all values in order of the Observables passed, where the |
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* first parameter is a value from the source Observable. (e.g. |
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* `a.withLatestFrom(b, c, (a1, b1, c1) => a1 + b1 + c1)`). If this is not |
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* passed, arrays will be emitted on the output Observable. |
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* @return {Observable} An Observable of projected values from the most recent |
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* values from each input Observable, or an array of the most recent values from |
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* each input Observable. |
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* @method withLatestFrom |
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* @owner Observable |
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*/ |
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function withLatestFrom() { |
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var args = []; |
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for (var _i = 0; _i < arguments.length; _i++) { |
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args[_i - 0] = arguments[_i]; |
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} |
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return function (source) { |
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var project; |
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if (typeof args[args.length - 1] === 'function') { |
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project = args.pop(); |
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} |
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var observables = args; |
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return source.lift(new WithLatestFromOperator(observables, project)); |
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}; |
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} |
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exports.withLatestFrom = withLatestFrom; |
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var WithLatestFromOperator = (function () { |
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function WithLatestFromOperator(observables, project) { |
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this.observables = observables; |
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this.project = project; |
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} |
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WithLatestFromOperator.prototype.call = function (subscriber, source) { |
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return source.subscribe(new WithLatestFromSubscriber(subscriber, this.observables, this.project)); |
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}; |
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return WithLatestFromOperator; |
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}()); |
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/** |
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* We need this JSDoc comment for affecting ESDoc. |
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* @ignore |
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* @extends {Ignored} |
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*/ |
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var WithLatestFromSubscriber = (function (_super) { |
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__extends(WithLatestFromSubscriber, _super); |
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function WithLatestFromSubscriber(destination, observables, project) { |
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_super.call(this, destination); |
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this.observables = observables; |
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this.project = project; |
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this.toRespond = []; |
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var len = observables.length; |
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this.values = new Array(len); |
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for (var i = 0; i < len; i++) { |
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this.toRespond.push(i); |
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} |
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for (var i = 0; i < len; i++) { |
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var observable = observables[i]; |
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this.add(subscribeToResult_1.subscribeToResult(this, observable, observable, i)); |
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} |
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} |
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WithLatestFromSubscriber.prototype.notifyNext = function (outerValue, innerValue, outerIndex, innerIndex, innerSub) { |
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this.values[outerIndex] = innerValue; |
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var toRespond = this.toRespond; |
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if (toRespond.length > 0) { |
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var found = toRespond.indexOf(outerIndex); |
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if (found !== -1) { |
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toRespond.splice(found, 1); |
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} |
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} |
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}; |
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WithLatestFromSubscriber.prototype.notifyComplete = function () { |
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// noop |
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}; |
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WithLatestFromSubscriber.prototype._next = function (value) { |
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if (this.toRespond.length === 0) { |
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var args = [value].concat(this.values); |
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if (this.project) { |
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this._tryProject(args); |
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} |
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else { |
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this.destination.next(args); |
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} |
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} |
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}; |
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WithLatestFromSubscriber.prototype._tryProject = function (args) { |
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var result; |
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try { |
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result = this.project.apply(this, args); |
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} |
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catch (err) { |
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this.destination.error(err); |
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return; |
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} |
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this.destination.next(result); |
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}; |
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return WithLatestFromSubscriber; |
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}(OuterSubscriber_1.OuterSubscriber)); |
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//# sourceMappingURL=withLatestFrom.js.map
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