Adds ServiceWorker Service

Adds ServiceWorker Service for Updating PWA

src/app/shared/service-worker/update.service.spec.ts

@@ -0,0 +1,16 @@
+import { TestBed } from '@angular/core/testing';
+
+import { UpdateService } from './update.service';
+
+describe('UpdateService', () => {
+  let service: UpdateService;
+
+  beforeEach(() => {
+    TestBed.configureTestingModule({});
+    service = TestBed.inject(UpdateService);
+  });
+
+  it('should be created', () => {
+    expect(service).toBeTruthy();
+  });
+});

src/app/shared/service-worker/update.service.ts

@@ -0,0 +1,26 @@
+import { Injectable } from '@angular/core';
+import {SwUpdate} from "@angular/service-worker";
+import {interval} from "rxjs";
+
+@Injectable({
+    providedIn: 'root'
+})
+export class UpdateService {
+
+    constructor(private swUpdate: SwUpdate) {
+        if (swUpdate.isEnabled) {
+            interval(6 * 60 * 60).subscribe(() => swUpdate.checkForUpdate()
+                .then(() => console.log('checking for updates')));
+        }
+    }
+
+    public checkForUpdates(): void {
+        this.swUpdate.available.subscribe(event => this.promptUser());
+    }
+
+    private promptUser(): void {
+        console.log('updating to new version');
+        this.swUpdate.activateUpdate().then(() => document.location.reload());
+    }
+
+}