barker/bookie/src/app/core/http-auth-interceptor.ts

import {Injectable} from '@angular/core';
import {HttpEvent, HttpHandler, HttpInterceptor, HttpRequest} from '@angular/common/http';

import {Observable, throwError} from 'rxjs';
import {catchError} from 'rxjs/operators';
import {ToasterService} from './toaster.service';
import {Router} from '@angular/router';
import {ConfirmDialogComponent} from '../shared/confirm-dialog/confirm-dialog.component';
import { MatDialog } from '@angular/material/dialog';

@Injectable()
export class HttpAuthInterceptor implements HttpInterceptor {

  constructor(private router: Router, private dialog: MatDialog, private toaster: ToasterService) {
  }

  intercept(req: HttpRequest<any>, next: HttpHandler):
    Observable<HttpEvent<any>> {
    return next.handle(req)
      .pipe(
        catchError((error: any) => {
            if (error.status === 401) {
              this.toaster.show('Danger', 'User has been logged out');
              const dialogRef = this.dialog.open(ConfirmDialogComponent, {
                width: '250px',
                data: {
                  title: 'Logged out!',
                  content: 'You have been logged out.\n' +
                    'You can press Cancel to stay on page and login in another tab to resume here,' +
                    ' or you can press Ok to navigate to the login page.'
                }
              });
              dialogRef.afterClosed().subscribe((result: boolean) => {
                if (result) {
                  this.router.navigate(['login']);
                }
              });
            }
            return throwError(error);
          }
        )
      );
  }
}