How to add SockJS into Angular 2 project?

Question

I use angular-cli to generate a new project. Now I want to add socketJs to the project, but keep getting errors in browser console:

GET http://localhost:4200/url-parse 404 (Not Found)
GET http://localhost:4200/inherits 404 (Not Found)
Unhandled Promise rejection: Error: XHR error (404 Not Found) loading http://localhost:4200/url-parse
        at XMLHttpRequest.wrapFn [as _onreadystatechange] (http://localhost:4200/vendor/zone.js/dist/zone.js:769:30)
        at ZoneDelegate.invokeTask (http://localhost:4200/vendor/zone.js/dist/zone.js:356:38)
        at Zone.runTask (http://localhost:4200/vendor/zone.js/dist/zone.js:256:48)
        at XMLHttpRequest.ZoneTask.invoke (http://localhost:4200/vendor/zone.js/dist/zone.js:423:34)
    Error loading http://localhost:4200/url-parse as "url-parse" from http://localhost:4200/vendor/sockjs-client/lib/main.js ; Zone: <root> ; Task: Promise.then ; Value: Error: Error: XHR error (404 Not Found) loading http://localhost:4200/url-parse(…)
Error: Uncaught (in promise): Error: Error: XHR error (404 Not Found) loading http://localhost:4200/url-parse(…)
GET http://localhost:4200/json3 404 (Not Found)
GET http://localhost:4200/debug 404 (Not Found)
GET http://localhost:4200/events 404 (Not Found)
GET http://localhost:4200/eventsource 404 (Not Found)
GET http://localhost:4200/crypto 404 (Not Found)
GET http://localhost:4200/json3 404 (Not Found)
GET http://localhost:4200/url-parse 404 (Not Found)
GET http://localhost:4200/debug 404 (Not Found)
GET http://localhost:4200/inherits 404 (Not Found)
Assertion failed: loading or loaded
GET http://localhost:4200/events 404 (Not Found)
Assertion failed: loading or loaded
GET http://localhost:4200/faye-websocket 404 (Not Found)
Assertion failed: loading or loaded
GET http://localhost:4200/eventsource 404 (Not Found)
Assertion failed: loading or loaded
GET http://localhost:4200/http 404 (Not Found)
GET http://localhost:4200/https 404 (Not Found)

This is my steps and configuration:

typings install sockjs-client --save --ambient

angular-cli-build.js

var Angular2App = require('angular-cli/lib/broccoli/angular2-app');

module.exports = function(defaults) {
  return new Angular2App(defaults, {
    vendorNpmFiles: [
      'systemjs/dist/system-polyfills.js',
      'systemjs/dist/system.src.js',
      'zone.js/dist/**/*.+(js|js.map)',
      'es6-shim/es6-shim.js',
      'reflect-metadata/**/*.+(ts|js|js.map)',
      'rxjs/**/*.+(js|js.map)',
      '@angular/**/*.+(js|js.map)',
      'sockjs-client/**/*.+(js)'
    ]
  });
};

system-config.ts

/** Map relative paths to URLs. */
const map: any = {
  'sockjs-client': 'vendor/sockjs-client/lib/entry.js'
};

/** User packages configuration. */
const packages: any = {
  'vendor/sockjs-client/lib': {
    'format': 'cjs',
    'defaultExtension': 'js'
  }
};

My custom service class:

import { Injectable } from '@angular/core';

import * as SockJS from 'sockjs-client';
import BaseEvent = __SockJSClient.BaseEvent;
import SockJSClass = __SockJSClient.SockJSClass;

@Injectable()
export class WebsocketService {

  private sockJs: SockJSClass;

  constructor() {
    console.log('constuctor');
    this.sockJs = new SockJS('/hello');
  }
}

Please let me know how to fix it, thanks a lot!

I can, however, eliminate some error by including the missing lib by adding them one by one in system-config.ts. But I doubt this is the right approach.

const map: any = {
  'sockjs-client': 'vendor/sockjs-client/lib/entry.js',
  'json3': 'vendor/sockjs-client/node_modules/json3/lib/json3.js',
  'url-parse': 'vendor/sockjs-client/node_modules/url-parse/index.js',
  'inherits': 'vendor/sockjs-client/node_modules/inherits/inherits.js',
  'debug': 'vendor/sockjs-client/node_modules/debug/debug.js',
  ...
};

Answer 1

In new version of angular2 CLI https://cli.angular.io/ it is simple to add library.

If you want to add only sockjs_client

1) npm i --save sockjs-client

2) In typings.d.ts add this declaration declare module 'sockjs-client';

But I would recommend to use STOMP-Over-WebSocket Service for angular 2

Install this npm packages

npm i --save stompjs
npm i --save sockjs-client
npm i --save ng2-stomp-service

In typings.d.ts

Add stompjs and sockjs-client module declaration

declare module 'stompjs';
declare module 'sockjs-client';

In app.module.ts

import { StompService } from 'ng2-stomp-service';

@NgModule({
  ...
  providers: [StompService]
})

In app.components.ts

import { StompService } from 'ng2-stomp-service';

private wsConf = {
  host:'test.com'
}

constructor(stomp: StompService) {

  stomp.configure(this.wsConf);

  stomp.startConnect().then(() => {
    console.log('connected');
  });


}

source https://github.com/devsullo/ng2-STOMP-Over-WebSocket

Answer 2

I found a solution to this problem.

The issue is that: npm install sockjs-client downloads sockjs-node instead of client. I hope they will fix it soon.

In your project you're pointing to vendor/sockjs-client/lib/entry.js instead you should download this file http://cdn.jsdelivr.net/sockjs/1/sockjs.min.js put it in your project and point to it in system-config.ts.

Answer 3

In Angular2, the easiest way to import sockjs is to use:

import 'your_path/sockjs-1.1.1.js'

but before you import, please modify part of the code in first line of 'sockjs-1.1.1.js'.

if("object"==typeof exports&&"undefined"!=typeof module)module.exports=e();else if("function"==typeof define&&define.amd)define([],e);else{var f;"undefined"!=typeof window?f=window:"undefined"!=typeof global?f=global:"undefined"!=typeof self&&(f=self),f.SockJS=e()}

replace the code above to:

window.SockJS = e()

after then SockJS could be access from anywhere because now it's a property of window in browser.Also you need to tell typescript SockJS is an ambient variable by adding:

declare let SockJS: any