Question

我的Angular 6拦截器出现问题。我已经将代码从Angular 5.x迁移到了6.0。和rxjs 5.x到6.x。当我尝试创建一个新的用户帐户时，该请求似乎被调用了两次。我知道这是因为我将错误记录到控制台。我注意到当我尝试从firebase auth获取Id令牌时，我得到了重复信息，请参见下面的代码片段。

intercept (request: HttpRequest<any>, next: HttpHandler): observable<HttpEvent<any>> {
return this.auth.getIdToken().pipe(
    mergeMap((token: any) => {
      if (token) {
        request = request.clone({ setHeaders: { Authorization: `Bearer ${token}` } });
      }

      return next.handle(request).pipe(
        tap((event: HttpEvent<any>) => {
          if (event instanceof HttpResponse) {

          }
        }, (err: any) => {
          if (err instanceof HttpErrorResponse) {
            if ((err.status === 401) || (err.status === 403)) {
             this.router.navigate([WellknownRoutesConstants.SIGN_IN], { queryParams: { returnUrl: this.router.routerState.snapshot.url }});
            }
          }
        })
    );

  }));

}

getIdToken (): Observable<any> {
  return ngFireAuth.authState.pipe(
    tap((user) => {
      if (user) {
        return observableOf(user.getIdToken());
      } else {
        return observableOf;
      }
    }),
    catchError(observableOf)
  );
}

Answer 1

格兰特的回答很好，但是有一个问题。

如果用户注销，则auth.idToken会发出一个值，因为令牌值更改为null。请求对象保持不变（但仍处于初始化状态），因此重复了HTTP请求。

我使用take(1)仅采用auth.idToken Observable发出的第一个值。我还更改为switchMap（请参阅take）：

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {

   return this.auth.idToken.pipe(
      take(1), // <-------------- only emit the first value!

      switchMap((token: any) => {
        if (token) {
          request = request.clone({
            setHeaders: { Authorization: `Bearer ${token}` }
          });
        }
        return next.handle(request);
      })

    );
}

Answer 2

自从升级到Angular 6 / RxJS 6以来，这对我有用。这是我的拦截器：

import { Injectable } from '@angular/core';
import { AngularFireAuth } from '@angular/fire/auth';
import {
  HttpRequest,
  HttpHandler,
  HttpEvent,
  HttpInterceptor
} from '@angular/common/http';
import { Observable } from 'rxjs';
import { mergeMap } from 'rxjs/operators';

@Injectable()

export class TokenInterceptor implements HttpInterceptor {

  constructor(
    private auth: AngularFireAuth
  ) {
    console.log('token interceptor constructor');
  }

  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    return this.auth.idToken.pipe(
      mergeMap((token: any) => {
        console.log(token);
        if (token) {
          request = request.clone({ setHeaders: { Authorization: `Bearer ${token}` } });
        }

        return next.handle(request);

    }));
  }
}

具有Firebase身份验证的拦截器

2 个答案: