constructor(routerService: RouterService, appService: AppService, userService: UserService) {
     super(appService);
     this.appService = appService;
     this.userService = userService;
     this.routerService = routerService;
     
     userService.getUser().then(user => this.init(user));
     
     this.subscribeEvent(AppEvent.SlidingNavVisible, (visible: boolean) => this.isSlidingNavVisible = visible);
     this.subscribeEvent(AppEvent.PageLoading, (loading: boolean) => this.isPageLoading = loading);
 }

        return Observable.create(observer => {
            this.userService.getUser().then((user: User) => {
                if (user) {
                    observer.next(true);
                }
                else {
                    observer.next(false);
                }

                observer.complete();
            });
        });

 logout() {
     this.userService.logout().then(() => this.logoutCompete());
 }

 register() {
     this.errMessage = false;
     this.userService.register(this.registerForm.value).then(user => this.loginComplete(user));
 }

 login() {
     this.errMessage = false;
     this.userService.login(this.loginForm.value).then(user => this.loginComplete(user));
 }