How to give session idle timeout in angular 6?

you can use the code below on the main or parent component. Let's say this is in the admin parent component and am assuming you have an authentication service so that you can know whether the user is logged

declare variables

   userActivity;
   userInactive: Subject<any> = new Subject();

in the constructor or on ngOnInit add

this.setTimeout();
 this.userInactive.subscribe(() => {
   this.logout();
 });  
 logout() {
 this.authService.logout();
 this.authService.redirectLogoutUser();
}

finally add the following methods

    setTimeout() {
    this.userActivity = setTimeout(() => {
      if (this.authService.isLoggedIn) {
        this.userInactive.next(undefined);
        console.log('logged out');
      }
    }, 420000);
  }

  @HostListener('window:mousemove') refreshUserState() {
    clearTimeout(this.userActivity);
    this.setTimeout();
  }

You can use bn-ng-idle npm for user idle / session timeout detection in angular apps. This blog post explanation will help you Learn how to Handle user idleness and session timeout in Angular

npm install bn-ng-idle

app.module.ts

import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
 
import { AppComponent } from './app.component';
import { BnNgIdleService } from 'bn-ng-idle'; // import bn-ng-idle service
 
 
@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule
  ],
  providers: [BnNgIdleService], // add it to the providers of your module
  bootstrap: [AppComponent]
})
export class AppModule { }

app.component.ts

import { Component } from '@angular/core';
import { BnNgIdleService } from 'bn-ng-idle'; // import it to your component
 
@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css']
})
export class AppComponent {
 
  constructor(private bnIdle: BnNgIdleService) { // initiate it in your component constructor
    this.bnIdle.startWatching(300).subscribe((res) => {
      if(res) {
          console.log("session expired");
      }
    })
  }
}

In the above example, I have invoked the startWatching(timeOutSeconds) method with 300 seconds (5 minutes) and subscribed to the observable, once the user is idle for five minute then the subscribe method will get invoked with the res parameter's value (which is a boolean) as true.

By checking whether the res is true or not, you can show your session timeout dialog or message. For brevity, I just logged the message to the console.

Option: 1: angular-user-idle.

Logic

• Library are waiting for a user's inactive for a 1 minutes (60 seconds).

• If inactive are detected then onTimerStart() is fired and
  returning a countdown for a 2 minutes (120 seconds).

• If user did notstop the timer by stopTimer() then time is up after 2 minutes (120 seconds) and onTimeout() is fire.

In AppModule:

@NgModule({
      imports: [
        BrowserModule,

        // Optionally you can set time for `idle`, `timeout` and `ping` in seconds.
        // Default values: `idle` is 600 (10 minutes), `timeout` is 300 (5 minutes) 
        // and `ping` is 120 (2 minutes).
        UserIdleModule.forRoot({idle: 600, timeout: 300, ping: 120})
      ],
      declarations: [AppComponent],
      bootstrap: [AppComponent]
    })

In any of your core componets:

    ngOnInit() {
        //Start watching for user inactivity.
        this.userIdle.startWatching();

        // Start watching when user idle is starting.
        this.userIdle.onTimerStart().subscribe(count => console.log(count));

        // Start watch when time is up.
        this.userIdle.onTimeout().subscribe(() => console.log('Time is up!'));
      }

Bonus: You can use "ping" to make request to refresh token in a given interval of time (e.g. every 10 mins).

Option: 2: Using ngrx

Please refer to the article in the link: https://itnext.io/inactivity-auto-logout-w-angular-and-ngrx-3bcb2fd7983f