22

✏️ Editing: combineLatest.js

import { Observable } from '../Observable';
import { argsArgArrayOrObject } from '../util/argsArgArrayOrObject';
import { from } from './from';
import { identity } from '../util/identity';
import { mapOneOrManyArgs } from '../util/mapOneOrManyArgs';
import { popResultSelector, popScheduler } from '../util/args';
import { createObject } from '../util/createObject';
import { OperatorSubscriber } from '../operators/OperatorSubscriber';
export function combineLatest() {
    var args = [];
    for (var _i = 0; _i < arguments.length; _i++) {
        args[_i] = arguments[_i];
    }
    var scheduler = popScheduler(args);
    var resultSelector = popResultSelector(args);
    var _a = argsArgArrayOrObject(args), observables = _a.args, keys = _a.keys;
    if (observables.length === 0) {
        return from([], scheduler);
    }
    var result = new Observable(combineLatestInit(observables, scheduler, keys
        ?
            function (values) { return createObject(keys, values); }
        :
            identity));
    return resultSelector ? result.pipe(mapOneOrManyArgs(resultSelector)) : result;
}
export function combineLatestInit(observables, scheduler, valueTransform) {
    if (valueTransform === void 0) { valueTransform = identity; }
    return function (subscriber) {
        maybeSchedule(scheduler, function () {
            var length = observables.length;
            var values = new Array(length);
            var active = length;
            var remainingFirstValues = length;
            var _loop_1 = function (i) {
                maybeSchedule(scheduler, function () {
                    var source = from(observables[i], scheduler);
                    var hasFirstValue = false;
                    source.subscribe(new OperatorSubscriber(subscriber, function (value) {
                        values[i] = value;
                        if (!hasFirstValue) {
                            hasFirstValue = true;
                            remainingFirstValues--;
                        }
                        if (!remainingFirstValues) {
                            subscriber.next(valueTransform(values.slice()));
                        }
                    }, function () {
                        if (!--active) {
                            subscriber.complete();
                        }
                    }));
                }, subscriber);
            };
            for (var i = 0; i < length; i++) {
                _loop_1(i);
            }
        }, subscriber);
    };
}
function maybeSchedule(scheduler, execute, subscription) {
    if (scheduler) {
        subscription.add(scheduler.schedule(execute));
    }
    else {
        execute();
    }
}
//# sourceMappingURL=combineLatest.js.map

MR SKB