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