Error using SockJS in Angular5 - "sockjs_client_1.SockJS is not a constructor"

Question

I am following this tutorial at the moment and I got to the point, where I have to instantiate my SockJS-Client inside my Angular5 Component.

Here is what I did in:

1. I exectuted the following commands to install the required libraries:

   npm install stompjs
   npm install sockjs-client
   npm install jquery
   

2. I imported the libraries to my component like so:

   import { Stomp } from 'stompjs';
   import { SockJS } from 'sockjs-client';
   import $ from 'jquery';
   

3. Finally I tried to instantiate SockJS:

   constructor(){
       this.initializeWebSocketConnection();
   }
   
   initializeWebSocketConnection(){
       let ws = new SockJS(this.serverUrl);  //<- This is the line causing the error
       this.stompClient = Stomp.over(ws);
       let that = this;
       this.stompClient.connect({}, function(frame) {
           that.stompClient.subscribe("/chat", (message) => {
               if(message.body) {
                   $(".chat").append("<div class='message'>"+message.body+"</div>")
                   console.log(message.body);
               }
           });
       });
   }
   

The error I am getting is:

ERROR Error: Uncaught (in promise): TypeError: sockjs_client_1.SockJS is not a constructor

I can't find anything about this problem.

Answer 1

Try either:

import * as SockJS from 'sockjs-client';

or

import SockJS from 'sockjs-client';