Angular2 WebSocket Class | Can connect to raw websocket url using engine.io-client and have the ability to reconnect it's self and emit connectivity status

app.component.ts

import { Component } from '@angular/core';
import {WebSocketClient} from './websocket-client';

@Component({
    selector: 'my-app',
    template: '<h1>Websocket connectivity: <small>{{connectivity}}</small></h1>'
})
export class AppComponent {
  connectivity:string;
  constructor() {
    var wsClient = new WebSocketClient('wss://websocket-server-tlimpanont.c9users.io/');

    wsClient.message$.subscribe( (data:any) => {
      console.log(data);
    });

    wsClient.connectivity$.subscribe( (connectivity:string) => {
      this.connectivity = connectivity;
    });

  }
}

websocket-client.ts

import { Observer, Observable, Subject } from 'rxjs/Rx';
import {EventEmitter} from '@angular/core';
const eio = require('engine.io-client');

export class WebSocketClient {
    public message$:Observable<any>;
    public connectivity$ = new EventEmitter();

    constructor(public webSocketUrl:string) {
        let connect$ = Observable.create(this.connect.bind(this));
        let connectionRetry$ = connect$.retryWhen((errorObs: Observable<any>) => errorObs.delay(2000));
        let result = connectionRetry$.do((socket: any) => {
          return Observable.create((observer: Observer<any>) => {
              socket.on('message', (data: any) => {
                  console.log(data);
                  observer.next(data);
              });

              socket.on('error', (error: any) => {
                  console.log(error);
                  observer.error(data);
              });
              return () => observer.complete();
          }).subscribe();
        });
        this.message$ = result.last();
    }
    private connect(observer: Observer<any>) {
        let socket = new eio.Socket(this.webSocketUrl);
        socket.binaryType = 'blob';
        socket.on('open', () => {
            console.log('open!')
            observer.next(socket);
            this.connectivity$.next('online');
        });
        socket.on('close', () => {
            console.log('close!')
            observer.error('close!');
            this.connectivity$.next('offline');
        });
      }
}