client/src/app/shared/auth/auth-interceptor.service.ts

   1 import { Observable, throwError as observableThrowError } from 'rxjs'
   2 import { catchError, switchMap } from 'rxjs/operators'
   3 import { Injectable, Injector } from '@angular/core'
   4 import { HTTP_INTERCEPTORS, HttpEvent, HttpHandler, HttpInterceptor, HttpRequest } from '@angular/common/http'
   5 import { AuthService } from '../../core'
   6
   7 @Injectable()
   8 export class AuthInterceptor implements HttpInterceptor {
   9   private authService: AuthService
  10
  11   // https://github.com/angular/angular/issues/18224#issuecomment-316957213
  12   constructor (private injector: Injector) {}
  13
  14   intercept (req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
  15     if (this.authService === undefined) {
  16       this.authService = this.injector.get(AuthService)
  17     }
  18
  19     const authReq = this.cloneRequestWithAuth(req)
  20
  21     // Pass on the cloned request instead of the original request
  22     // Catch 401 errors (refresh token expired)
  23     return next.handle(authReq)
  24                .pipe(
  25                  catchError(err => {
  26                    if (err.status === 401 && err.error && err.error.code === 'invalid_token') {
  27                      return this.handleTokenExpired(req, next)
  28                    }
  29
  30                    return observableThrowError(err)
  31                  })
  32                )
  33   }
  34
  35   private handleTokenExpired (req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
  36     return this.authService.refreshAccessToken()
  37                .pipe(
  38                  switchMap(() => {
  39                    const authReq = this.cloneRequestWithAuth(req)
  40
  41                    return next.handle(authReq)
  42                  })
  43                )
  44   }
  45
  46   private cloneRequestWithAuth (req: HttpRequest<any>) {
  47     const authHeaderValue = this.authService.getRequestHeaderValue()
  48
  49     if (authHeaderValue === null) return req
  50
  51     // Clone the request to add the new header
  52     return req.clone({ headers: req.headers.set('Authorization', authHeaderValue) })
  53   }
  54 }
  55
  56 export const AUTH_INTERCEPTOR_PROVIDER = {
  57   provide: HTTP_INTERCEPTORS,
  58   useClass: AuthInterceptor,
  59   multi: true
  60 }