FromObservable.js 5.0 KB
"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 isArray_1 = require('../util/isArray');
var isArrayLike_1 = require('../util/isArrayLike');
var isPromise_1 = require('../util/isPromise');
var PromiseObservable_1 = require('./PromiseObservable');
var IteratorObservable_1 = require('./IteratorObservable');
var ArrayObservable_1 = require('./ArrayObservable');
var ArrayLikeObservable_1 = require('./ArrayLikeObservable');
var iterator_1 = require('../symbol/iterator');
var Observable_1 = require('../Observable');
var observeOn_1 = require('../operators/observeOn');
var observable_1 = require('../symbol/observable');
/**
 * We need this JSDoc comment for affecting ESDoc.
 * @extends {Ignored}
 * @hide true
 */
var FromObservable = (function (_super) {
    __extends(FromObservable, _super);
    function FromObservable(ish, scheduler) {
        _super.call(this, null);
        this.ish = ish;
        this.scheduler = scheduler;
    }
    /**
     * Creates an Observable from an Array, an array-like object, a Promise, an
     * iterable object, or an Observable-like object.
     *
     * <span class="informal">Converts almost anything to an Observable.</span>
     *
     * <img src="./img/from.png" width="100%">
     *
     * Convert various other objects and data types into Observables. `from`
     * converts a Promise or an array-like or an
     * [iterable](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Iteration_protocols#iterable)
     * object into an Observable that emits the items in that promise or array or
     * iterable. A String, in this context, is treated as an array of characters.
     * Observable-like objects (contains a function named with the ES2015 Symbol
     * for Observable) can also be converted through this operator.
     *
     * @example <caption>Converts an array to an Observable</caption>
     * var array = [10, 20, 30];
     * var result = Rx.Observable.from(array);
     * result.subscribe(x => console.log(x));
     *
     * // Results in the following:
     * // 10 20 30
     *
     * @example <caption>Convert an infinite iterable (from a generator) to an Observable</caption>
     * function* generateDoubles(seed) {
     *   var i = seed;
     *   while (true) {
     *     yield i;
     *     i = 2 * i; // double it
     *   }
     * }
     *
     * var iterator = generateDoubles(3);
     * var result = Rx.Observable.from(iterator).take(10);
     * result.subscribe(x => console.log(x));
     *
     * // Results in the following:
     * // 3 6 12 24 48 96 192 384 768 1536
     *
     * @see {@link create}
     * @see {@link fromEvent}
     * @see {@link fromEventPattern}
     * @see {@link fromPromise}
     *
     * @param {ObservableInput<T>} ish A subscribable object, a Promise, an
     * Observable-like, an Array, an iterable or an array-like object to be
     * converted.
     * @param {Scheduler} [scheduler] The scheduler on which to schedule the
     * emissions of values.
     * @return {Observable<T>} The Observable whose values are originally from the
     * input object that was converted.
     * @static true
     * @name from
     * @owner Observable
     */
    FromObservable.create = function (ish, scheduler) {
        if (ish != null) {
            if (typeof ish[observable_1.observable] === 'function') {
                if (ish instanceof Observable_1.Observable && !scheduler) {
                    return ish;
                }
                return new FromObservable(ish, scheduler);
            }
            else if (isArray_1.isArray(ish)) {
                return new ArrayObservable_1.ArrayObservable(ish, scheduler);
            }
            else if (isPromise_1.isPromise(ish)) {
                return new PromiseObservable_1.PromiseObservable(ish, scheduler);
            }
            else if (typeof ish[iterator_1.iterator] === 'function' || typeof ish === 'string') {
                return new IteratorObservable_1.IteratorObservable(ish, scheduler);
            }
            else if (isArrayLike_1.isArrayLike(ish)) {
                return new ArrayLikeObservable_1.ArrayLikeObservable(ish, scheduler);
            }
        }
        throw new TypeError((ish !== null && typeof ish || ish) + ' is not observable');
    };
    /** @deprecated internal use only */ FromObservable.prototype._subscribe = function (subscriber) {
        var ish = this.ish;
        var scheduler = this.scheduler;
        if (scheduler == null) {
            return ish[observable_1.observable]().subscribe(subscriber);
        }
        else {
            return ish[observable_1.observable]().subscribe(new observeOn_1.ObserveOnSubscriber(subscriber, scheduler, 0));
        }
    };
    return FromObservable;
}(Observable_1.Observable));
exports.FromObservable = FromObservable;
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