Scouting: Add ability to scout offline

Signed-off-by: Filip Kujawa <filip.j.kujawa@gmail.com>
Change-Id: I0e0c0be033824c05b6c239d38eb79d95745fceec
diff --git a/scouting/www/app/app.module.ts b/scouting/www/app/app.module.ts
index ccc4840..decd1f3 100644
--- a/scouting/www/app/app.module.ts
+++ b/scouting/www/app/app.module.ts
@@ -1,6 +1,7 @@
-import {NgModule} from '@angular/core';
+import {NgModule, isDevMode} from '@angular/core';
 import {BrowserModule} from '@angular/platform-browser';
 import {BrowserAnimationsModule} from '@angular/platform-browser/animations';
+import {ServiceWorkerModule} from '@angular/service-worker';
 
 import {App} from './app';
 import {EntryModule} from '../entry';
@@ -17,6 +18,12 @@
   imports: [
     BrowserModule,
     BrowserAnimationsModule,
+    ServiceWorkerModule.register('./ngsw-worker.js', {
+      enabled: !isDevMode(),
+      // Register the ServiceWorker as soon as the application is stable
+      // or after 30 seconds (whichever comes first).
+      registrationStrategy: 'registerWhenStable:30000',
+    }),
     EntryModule,
     NotesModule,
     MatchListModule,