Session Expiration Alert

An Angular module to time session expiration. When user session idle time reaches a threshold, then pop up a modal dialog to let user choose to continue session or log out the system. When user session is expired, timer will stop and user will be logged out. A http interceptor is registered, so that session timer will restart at every http request.

Dependencies: Angular 6+, Bootstrap 4+ (css), NgBootstrap 3+.

Demo

Usage

In app.module.ts

@NgModule({
  declarations: [AppComponent],
  imports: [
    BrowserModule,
    HttpClientModule,
    NgbModule.forRoot(),
    SessionExpirationAlertModule.forRoot()
    // *** your other import modules
  ],
  providers: [
    {
      provide: SessionInteruptService,
      useClass: AppSessionInteruptService
    }
  ],
  bootstrap: [AppComponent]
})
export class AppModule {}

In app.component.html

<session-expiration-alert></session-expiration-alert>

In app-session-interupt.service.ts

@Injectable()
export class AppSessionInteruptService extends SessionInteruptService {
  constructor(private readonly httpClient: HttpClient) {
    super();
  }
  continueSession() {
    console.log(`I issue an API request to server.`);
  }
  stopSession() {
    console.log(`I logout.`);
  }
}

Then the SessionTimerService will start to count down at each second.

• To provide actions in the alert modal dialog, you want to provide a AppSessionInteruptService class, which will be able to continue session via refreshing cookie, or stop session via logging out.

• To start/stop/reset timer, inject SessionTimerService into your component or service, then call startTimer(), stopTimer(), resetTimer() as needed.

• To get the remain time (in seconds), you can subscribe to remainSeconds$ in SessionTimerService.

Configuration

 imports: [
   // ***
    SessionExpirationAlertModule.forRoot({totalMinutes: 0.5}),
   //***
  ],

The SessionExpirationAlertModule accepts a configuration with interface of SessionExpirationConfig, which is an optional input and has a default value of total minutes = 20 min.

<session-expiration-alert
  [startTimer]="true"
  [alertAt]="2*60"
></session-expiration-alert>

[optional] startTimer indicates if the app needs to work on session expiration check or not. Default: true.

[optional] alertAt indicates when the alert modal dialog should show up. The value means how many seconds left till session becomes expired. Default: 60 (seconds).