Reading response headers from an API response - Angular 5 + TypeScript

Question

I run the HTTPrequest and get a valid response from it. The response also contains the X-Token header I want to read. I am trying the code below to read the headers, however, I get a null value as a result

this.currentlyExecuting.request = this.http.request(reqParams.type, reqParams.url, {
    body: reqParams.body,
    responseType: 'json',
    observe: 'response'
}).subscribe(
    (_response: any) => {
        // Also tried _response.headers.init();
        const header = _response.headers.get('X-Token');
        console.log(header);
        onComplete(_response.body);
     },
    _error => {
        onComplete({
            code: -1,
            message: Constants.WEBSERVICE_INTERNET_NOT_CONNNECTED
        });
    }
);

The response APIwhen checking in Chrome inspect shows that the header is present. I tried looking at a few related questions about StackOverflow, but nothing helped.

Answer 1

x- ? "access-control-expose-headers". ,

HTTP, , { observe: 'response'}

http
  .get<any>('url', {observe: 'response'})
  .subscribe(resp => {
    console.log(resp.headers.get('X-Token'));
  });

Answer 2

HttpClient. .

http
  .get<any>('url', {observe: 'response'})
  .subscribe(resp => {
    console.log(resp.headers.get('X-Token'));
  });

Answer 3

Hrishikesh Kale, Access-Control-Expose-Headers.

WebAPI/MVC:

protected void Application_BeginRequest()
        {
            if (HttpContext.Current.Request.HttpMethod == "OPTIONS")
            {
                //These headers are handling the "pre-flight" OPTIONS call sent by the browser
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Methods", "GET, POST, OPTIONS");
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Headers", "*");
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Credentials", "true");
                HttpContext.Current.Response.AddHeader("Access-Control-Allow-Origin", "http://localhost:4200");
                HttpContext.Current.Response.AddHeader("Access-Control-Expose-Headers", "TestHeaderToExpose");
                HttpContext.Current.Response.End();
            }
        }

- , webApiconfig.cs.

config.EnableCors(new EnableCorsAttribute("", headers: "", methods: "*",exposedHeaders: "TestHeaderToExpose") { SupportsCredentials = true });

** web.config, . *

<httpProtocol>
   <customHeaders>
      <add name="Access-Control-Expose-Headers" value="TestHeaderToExpose" />
   </customHeaders>
</httpProtocol>

.

!

Answer 4

POST authorization header JWT Token. , Expose Header . , , Authorization Exposed Header filter class.

response.addHeader("Access-Control-Expose-Headers", "Authorization");
response.addHeader("Access-Control-Allow-Headers", "Authorization, X-PINGOTHER, Origin, X-Requested-With, Content-Type, Accept, X-Custom-header");
response.addHeader(HEADER_STRING, TOKEN_PREFIX + token); // HEADER_STRING == Authorization

.

this.authenticationService.login(this.f.email.value, this.f.password.value)
  .pipe(first())
  .subscribe(
    (data: HttpResponse<any>) => {
      console.log(data.headers.get('authorization'));
    },
    error => {
      this.loading = false;
    });

.

return this.http.post<any>(Constants.BASE_URL + 'login', {username: username, password: password},
  {observe: 'response' as 'body'})
  .pipe(map(user => {
       return user;
  }));

Answer 5

(Angular 6):

import { HttpClient, HttpHeaders, HttpResponse } from '@angular/common/http';

const httpOptions = {
  headers: new HttpHeaders({ 'Content-Type': 'application/json' }),
  observe: 'response' as 'response'
};

this.http.post(link,body,httpOptions).subscribe((res: HttpResponse<any>) => {
  console.log(res.headers.get('token-key-name'));
})

Answer 6

,

let main_headers = {}
this.http.post(url,
  {email: this.username, password: this.password},
  {'headers' : new HttpHeaders ({'Content-Type' : 'application/json'}), 'responseType': 'text', observe:'response'})
  .subscribe(response => {
    const keys = response.headers.keys();
    let headers = keys.map(key => {
      '${key}: ${response.headers.get(key)}'
        main_headers[key] = response.headers.get(key)
       }
      );
  });

json.

header_list['X-Token']