definma-ui/src/app/login.service.ts

import { Injectable } from '@angular/core';
import {ApiService} from './api.service';
import {ActivatedRouteSnapshot, CanActivate, RouterStateSnapshot} from '@angular/router';
import {LocalStorageService} from 'angular-2-local-storage';

@Injectable({
  providedIn: 'root'
})
export class LoginService implements CanActivate {

  private loggedIn = false;

  constructor(
    private api: ApiService,
    private storage: LocalStorageService
  ) {
    this.login();
  }

  login(username = '', password = '') {
    return new Promise(resolve => {
      if (username !== '') {
        this.storage.set('basicAuth', btoa(username + ':' + password));
      }
      this.api.get('/authorized').subscribe((data: any) => {
          if (data.status === 'Authorization successful') {
            this.loggedIn = true;
            resolve(true);
          }
          else {
            this.loggedIn = false;
            this.storage.remove('basicAuth');
            resolve(false);
          }
        },
        () => {
          this.loggedIn = false;
          this.storage.remove('basicAuth');
          resolve(false);
        });
    });
  }

  canActivate(route: ActivatedRouteSnapshot = null, state: RouterStateSnapshot = null) {
    return this.loggedIn;
  }
}