在Angular中验证JWT的最佳实践（检测令牌更改）

Question

I have a very basic property that checks if token is expired or not:

  get isExpired():boolean {
      return !!localStorage && 
             !!localStorage.getItem("token") && 
             !this.jwt.isTokenExpired(localStorage.getItem("token"));
  }

What is the best practice to keep watching this property in angular?

It might not be the best practice but in AngularJs I could use $scope.$watch

Is there any similar way to achieve the same functionality in Angular 4?

Thanks in advance!

Answer 1

I see different solutions

1. Use Guards to check your token expiration date on every change of route https://angular.io/guide/router#milestone-5-route-guards

2. Create a service that checks on the token expiration every second ,

    Observable .interval(1000) .timeInterval() .flatMap(() => this.authenticationService.isTokenExpired()) .filter(isExpired => isExpired) .subscribe(isExpired => { this.router.navigateByUrl("/login") }); 

this assumes that this.authenticationService.isTokenExpired() returns an Observable<boolean>