@gooddata/gooddata-js/lib/DataLayer/utils/async.js

GoodData JavaScript SDK

"use strict";
var __importDefault = (this && this.__importDefault) || function (mod) {
    return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
// (C) 2007-2020 GoodData Corporation
var identity_1 = __importDefault(require("lodash/identity"));
var rxjs_1 = require("rxjs");
exports.Subscription = rxjs_1.Subscription;
var operators_1 = require("rxjs/operators");
/**
 * Creates infinite stream
 * Usage:
 * const subject = createSubject(
 *      (result) => console.log('Success:', result),
 *      (error) => console.error('Error:', error)
 * );
 * subject.next(promise1);
 * subject.next(promise2);
 *
 * subject.unsubscribe();
 *
 * @method createSubject
 * @param {StreamSuccessHandler<T>} successHandler
 * @param {StreamErrorHandler} errorHandler
 * @return {ISubject<Promise<T>>}
 */
function createSubject(successHandler, errorHandler) {
    var subject = new rxjs_1.Subject();
    var subscription = subject
        .pipe(
    // This ensures we get last added promise
    operators_1.switchMap(identity_1.default), 
    // Streams are closed on error by default so we need this workaround
    operators_1.catchError(function (error, caught) {
        errorHandler(error); // handle error
        return caught; // stream continue
    }))
        .subscribe(successHandler);
    var wrapper = {
        next: function (promise) {
            subject.next(promise);
        },
        unsubscribe: function () {
            subscription.unsubscribe();
            subject.unsubscribe();
        },
    };
    return wrapper;
}
exports.createSubject = createSubject;