Can't get app to navigate to portal

问题

I'm trying to write a route guard. Here's my route...

{ path: 'portal', component: PortalComponent, canActivate: [AuthGuard] }

And here's AuthGuard:

@Injectable()
export class AuthGuard implements CanActivate {
    constructor(private appState: ApplicationState, private router: Router) {}

    canActivate(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<boolean> {
        let url: string = state.url;
        return this.checkLogin(url);
    }

    checkLogin(url: string): Observable<boolean> {
        return this.appState.User.map(
            (user) => {
                if (user.UserToken) return true;

                this.navToLogin(url);
                return false;
            }
        );
    }

    private navToLogin(redirUrl: string) {
        this.appState.RedirectUrl = redirUrl;
        this.router.navigate(['/']);
    }
}

And here's ApplicationState where you get the User from...

@Injectable()
export class ApplicationState {
    private _user: BehaviorSubject<LoginUser> = new BehaviorSubject<LoginUser>(new LoginUser());

    get User() {
        return this._user.asObservable();
    }
}

I want the user to be able to access the /portal route if the UserToken exists on the User object. However, if the token does not exist, I want the user to navigate to the login page (default route /).

I have a link to /portal that I tried clicking. And the appState.User.map inside checkLogin() returns true, however, the app never navigates to /portal.

What am I doing wrong? Is this one of those "cold observable" situations?

回答1:

Try this:

@Injectable()
export class ApplicationState {
    private _user: BehaviorSubject<LoginUser> = new BehaviorSubject<LoginUser>(new LoginUser());

    get User() {
        return this._user.value;
    }
    // login(user: LoginUser) { this._user.next(user); }
}


@Injectable()
export class AuthGuard implements CanActivate {
    // ...

    checkLogin(url: string): boolean {
      if (this.appState.User.UserToken) return true;

      this.navToLogin(url);
      return false;
    }

    // ...
}

来源：https://stackoverflow.com/questions/39853352/cant-get-app-to-navigate-to-portal