src/shared/services/WebSocketService.ts

   1 import { PersonViewSafe, WebSocketJsonResponse } from "lemmy-js-client";
   2 import { Observable } from "rxjs";
   3 import { share } from "rxjs/operators";
   4 import {
   5   ExponentialBackoff,
   6   Websocket as WS,
   7   WebsocketBuilder,
   8 } from "websocket-ts";
   9 import { wsUri } from "../env";
  10 import { isBrowser } from "../utils";
  11
  12 export class WebSocketService {
  13   private static _instance: WebSocketService;
  14   private ws: WS;
  15   public subject: Observable<any>;
  16
  17   public admins: PersonViewSafe[];
  18   public banned: PersonViewSafe[];
  19
  20   private constructor() {
  21     let firstConnect = true;
  22
  23     this.subject = new Observable((obs: any) => {
  24       this.ws = new WebsocketBuilder(wsUri)
  25         .onMessage((_i, e) => {
  26           try {
  27             obs.next(JSON.parse(e.data.toString()));
  28           } catch (err) {
  29             console.log(err);
  30           }
  31         })
  32         .onOpen(() => {
  33           console.log(`Connected to ${wsUri}`);
  34
  35           if (!firstConnect) {
  36             let res: WebSocketJsonResponse<any> = {
  37               reconnect: true,
  38             };
  39             obs.next(res);
  40           }
  41           firstConnect = false;
  42         })
  43         .onRetry(() => {
  44           console.log("Retrying websocket connection...");
  45         })
  46         .onClose(() => {
  47           console.error("Websocket closed.");
  48         })
  49         .withBackoff(new ExponentialBackoff(100, 7))
  50         .build();
  51     }).pipe(share());
  52
  53     if (isBrowser()) {
  54       window.onunload = () => {
  55         this.ws.close();
  56
  57         // Clears out scroll positions.
  58         sessionStorage.clear();
  59       };
  60     }
  61   }
  62
  63   public send(data: string) {
  64     this.ws.send(data);
  65   }
  66
  67   public static get Instance() {
  68     return this._instance || (this._instance = new this());
  69   }
  70 }