Angular HttpClient append headers to HttpHeaders [duplicate]

问题

I am upgrading from the HttpServer to the HttpClientService and as part of that I have to switch my headers from Headers to HttpHeaders. However For some reason my custom headers are no longer being appended. What do I need to update to have the headers appended?

  private getHeaders(headers?: HttpHeaders): HttpHeaders {
    if (!headers) {
      headers = new HttpHeaders();
    }
    headers.delete('authorization');
    const token: any = this.storageService.getItem('token');
    if (token) {
      headers.append('Authorization', 'Bearer ' + token);
    }
    const user: User = this.storageService.getObject('user');
    if (user && Object.keys(user).length) {
      headers.append('X-Session-ID', user.uuid);
      headers.append('X-Correlation-ID', this.uuidService.generateUuid());
    }
    return headers;
  }

That method returns a httpHeader but it's empty.

回答1:

HttpHeaders.append returns a clone of the headers with the value appened, it does not update the object. You need to set the returned value to the headers.

angular/packages/common/http/src/headers.ts

append(name: string, value: string|string[]): HttpHeaders { 
  return this.clone({name, value, op: 'a'}); 
}

So to append the headers you do this.

let headers: HttpHeaders = new HttpHeaders();
headers = headers.append('Content-Type', 'application/json');
headers = headers.append('x-corralation-id', '12345');

and boom!

来源：https://stackoverflow.com/questions/47805542/angular-httpclient-append-headers-to-httpheaders

标签

angular

angular-httpclient