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   LRUBuffer,
   7   Websocket as WS,
   8   WebsocketBuilder,
   9 } from "websocket-ts";
  10 import { wsUri } from "../env";
  11 import { isBrowser } from "../utils";
  12
  13 export class WebSocketService {
  14   private static _instance: WebSocketService;
  15   private ws: WS;
  16   public subject: Observable<any>;
  17
  18   public admins: PersonViewSafe[];
  19   public banned: PersonViewSafe[];
  20
  21   private constructor() {
  22     let firstConnect = true;
  23
  24     this.subject = new Observable((obs: any) => {
  25       this.ws = new WebsocketBuilder(wsUri)
  26         .onMessage((_i, e) => {
  27           try {
  28             obs.next(JSON.parse(e.data.toString()));
  29           } catch (err) {
  30             console.log(err);
  31           }
  32         })
  33         .onOpen(() => {
  34           console.log(`Connected to ${wsUri}`);
  35
  36           if (!firstConnect) {
  37             let res: WebSocketJsonResponse<any> = {
  38               reconnect: true,
  39             };
  40             obs.next(res);
  41           }
  42           firstConnect = false;
  43         })
  44         .onRetry(() => {
  45           console.log("Retrying websocket connection...");
  46         })
  47         .onClose(() => {
  48           console.error("Websocket closed.");
  49         })
  50         .withBackoff(new ExponentialBackoff(100, 7))
  51         .withBuffer(new LRUBuffer(1000))
  52         .build();
  53     }).pipe(share());
  54
  55     if (isBrowser()) {
  56       window.onunload = () => {
  57         this.ws.close();
  58
  59         // Clears out scroll positions.
  60         sessionStorage.clear();
  61       };
  62     }
  63   }
  64
  65   public send(data: string) {
  66     this.ws.send(data);
  67   }
  68
  69   public static get Instance() {
  70     return this._instance || (this._instance = new this());
  71   }
  72 }