HTTP Interceptor Library for JSON Web Token Authorisation

I was looking for an interceptor library for HTTP requests made from my Angular web app to backend services. The idea is to inject every request with Authorization header containing user JWT access token. Found a popular one in GitHub, https://github.com/auth0/angular2-jwt.

First install the library:

npm install @auth0/angular-jwt

Then in app.module.ts file, add the codes below. Note that my app has an authentication class (AuthService) that manages all the authentication functionalities, including retrieving user JWT access token.

. . .
import { JwtModule, JWT_OPTIONS } from '@auth0/angular-jwt';
import { AuthService } from './services/auth.service';

export function jwtOptionsFactory(authService: AuthService) {
  return {
    tokenGetter: () => {
      return authService.getUserAccessToken();
    },
    allowedDomains: ["localhost:5555"]  // my local dev environment
  }
}


@NgModule({
  imports: [
    JwtModule.forRoot({
      jwtOptionsProvider: {
        provide: JWT_OPTIONS,
        useFactory: jwtOptionsFactory,
        deps: [AuthService]
      }
    }),
    . . .
  ],
  . . .
})

export class AppModule { }

Now all the HTTP requests will have 'Authorization: Bearer [TOKEN]' added in the headers.