ngx-admin/src/app/@theme/components/header/header.component.ts

import { Component, OnDestroy, OnInit } from '@angular/core';
import { NbMediaBreakpointsService, NbMenuService, NbSidebarService, NbThemeService } from '@nebular/theme';

import { UserData } from '../../../@core/data/users';
import { LayoutService } from '../../../@core/utils';
import { map, takeUntil } from 'rxjs/operators';
import { Subject } from 'rxjs';
import { User } from '../../../@core/data/user';
import { Router } from '@angular/router';
import { LoginService } from '../../../auth/login.service';

@Component({
  selector: 'ngx-header',
  styleUrls: ['./header.component.scss'],
  templateUrl: './header.component.html',
})
export class HeaderComponent implements OnInit, OnDestroy {

  private destroy$: Subject<void> = new Subject<void>();
  userPictureOnly: boolean = false;
  username: any;
  roles: any;
  userpicture: any;

  themes = [
    {
      value: 'default',
      name: 'Light',
    },
    {
      value: 'dark',
      name: 'Dark',
    },
    {
      value: 'cosmic',
      name: 'Cosmic',
    },
    {
      value: 'corporate',
      name: 'Corporate',
    },
  ];

  currentTheme = 'default';

  userMenu = [{ title: 'User Role(s)' }];

  constructor(private sidebarService: NbSidebarService,
    private router: Router,
    private menuService: NbMenuService,
    private themeService: NbThemeService,
    private layoutService: LayoutService,
    private loginService: LoginService,
    private breakpointService: NbMediaBreakpointsService) {
  }

  ngOnInit() {

    this.username = localStorage.getItem('username');
    this.roles = localStorage.getItem('roles');
    this.userpicture = 'assets/images/eva.png';

    if (this.username == null) {
      this.router.navigate(['/auth/login']);
    }
    
    this.username = this.username.replace(/['"]+/g, '');

    this.currentTheme = this.themeService.currentTheme;

    const { xl } = this.breakpointService.getBreakpointsMap();
    this.themeService.onMediaQueryChange()
      .pipe(
        map(([, currentBreakpoint]) => currentBreakpoint.width < xl),
        takeUntil(this.destroy$),
      )
      .subscribe((isLessThanXl: boolean) => this.userPictureOnly = isLessThanXl);

    this.themeService.onThemeChange()
      .pipe(
        map(({ name }) => name),
        takeUntil(this.destroy$),
      )
      .subscribe(themeName => this.currentTheme = themeName);
  }

  logout(){
    this.loginService.logout();
  }

  ngOnDestroy() {
    this.destroy$.next();
    this.destroy$.complete();
  }

  changeTheme(themeName: string) {
    this.themeService.changeTheme(themeName);
  }

  toggleSidebar(): boolean {
    this.sidebarService.toggle(true, 'menu-sidebar');
    this.layoutService.changeLayoutSize();

    return false;
  }

  navigateHome() {
    this.menuService.navigateHome();
    return false;
  }
}