Move angular services to separate directory

src/app/services/websocket.service.ts

@@ -0,0 +1,58 @@
+import { Injectable } from '@angular/core';
+import { QueueingSubject } from 'queueing-subject';
+import { Observable } from 'rxjs/Observable';
+import websocketConnect from 'rxjs-websockets';
+import { filter, map, share } from 'rxjs/operators';
+import { WSMessage } from './wsmessage';
+
+
+function jsonWebsocketConnect(url: string, input: Observable<object>, protocols?: string | string[]) {
+  const jsonInput = input.pipe(map(message => JSON.stringify(message)));
+  const { connectionStatus, messages } = websocketConnect(url, jsonInput, protocols);
+  const jsonMessages = messages.pipe(map(message => JSON.parse(message)));
+  return { connectionStatus, messages: jsonMessages };
+}
+
+@Injectable()
+export class WebSocketService {
+  private uplink: QueueingSubject<object>;
+  public downlink: Observable<WSMessage<undefined>>;
+
+  constructor() {
+
+  }
+
+  public connect() {
+    if (this.downlink) {
+      return;
+    }
+
+    // Using share() causes a single WebSocket to be created when the first
+    // observer subscribes. This socket is shared with subsequent observers
+    // and closed when the observer count falls to zero.
+    const wsproto = (location.protocol === 'https:') ? 'wss://' : 'ws://';
+    this.downlink = jsonWebsocketConnect(
+      wsproto + window.location.host + '/ws',
+      this.uplink = new QueueingSubject<object>()
+    ).messages.pipe(
+        map(message => <WSMessage<undefined>> message),
+        share()
+      );
+    console.log('ws connected');
+  }
+
+  public observeAnchor<T>(anchor: string): Observable<WSMessage<T>> {
+    return this.downlink.pipe(filter(message => message.anchor === anchor));
+  }
+
+  public send(anchor: string, data: any): void {
+    // If the WebSocket is not connected then the QueueingSubject will ensure
+    // that messages are queued and delivered when the WebSocket reconnects.
+    // A regular Subject can be used to discard messages sent when the WebSocket
+    // is disconnected.
+    this.uplink.next({
+      'anchor': anchor,
+      'data': data
+    });
+  }
+}