how to read content-disposition headers from server response angular 2

Question

I am unable to find, how to read filename from content disposition in angular 2 documentation. Can someone guide read the headers from server in angular 2content headers

Answer 1

With new Angular Http, one can try the following in the Service code.

  downloadLink(): Observable<HttpResponse<Blob>> {
    return this.http.get<Blob>(this.someURL, {
      observe: 'response',
      responseType: 'blob' as 'json'
    });
  }

And use the above as

 this.someService
  .downloadLink()
  .subscribe(
    (resp: HttpResponse<Blob>) => {
      console.log(resp.headers.get('content-disposition'));
      data = resp.body
    });

Also, on the server side, one needs to set the following header in response. 'Access-Control-Expose-Headers': 'Content-Disposition'

Like in Java Spring Boot one can do the same using

    final HttpHeaders headers = new HttpHeaders();
    headers.add(HttpHeaders.CONTENT_DISPOSITION, "attachment; filename=1.xlsx");
    headers.add(HttpHeaders.ACCESS_CONTROL_EXPOSE_HEADERS, HttpHeaders.CONTENT_DISPOSITION);

Answer 2

To those complaining that the best solution is not working, and only content-type is in the headers, you need to set 'Access-Control-Expose-Headers': 'Content-Disposition' ON SERVER SIDE. I am using asp.net core, then I have to do the following.

app.UseCors(builder =>
                builder.WithOrigins(originsAllowed.ToArray())
                    .AllowAnyMethod()
                    .AllowAnyHeader()
                    .WithExposedHeaders("Content-Disposition")

Answer 3

In angular, we can read File Name like as show below,

  this.http.post(URL, DATA).subscribe(
        (res) => {
            var contentDisposition = res.headers.get('content-disposition');
            var filename = contentDisposition.split(';')[1].split('filename')[1].split('=')[1].trim();
            console.log(filename);
        });

But the main thing is that we need to specify Access-Control-Expose-Header in API as shown below,

Note: The last line is mandatory

FileInfo file = new FileInfo(FILEPATH);

HttpResponseMessage response = new HttpResponseMessage(HttpStatusCode.OK);
response.Content.Headers.ContentDisposition = new ContentDispositionHeaderValue("attachment")
{
    FileName = file.Name
};
response.Content.Headers.Add("Access-Control-Expose-Headers", "Content-Disposition");

Answer 4

With Angular 9 and Expresss

Need to Allow this header in Express

res.setHeader('Access-Control-Expose-Headers', 'Content-Disposition');

Angular

this.http.get(url, { observe: 'response', responseType: 'blob' as 'json' })
.subscribe((res: any) => {
    console.log(res.headers.get('content-disposition'));
});

Answer 5

In Angular 7 the up-voted method don't work, you need to do it like this :

const responseHeaderFilename = response.headers.get('content-disposition');

Please find Angular official docs for more details: https://angular.io/guide/http#reading-the-full-response

and also make sure that the "Content-Disposition" is exposed as in @mslugx answer

Answer 6

To get the filename from response header.

(data)=>{  //the 'data' is response of file data with responseType: ResponseContentType.Blob.
    let filename = data.headers.get('content-disposition').split(';')[1].split('=')[1].replace(/\"/g, '')
}

Answer 7

CORS requests only expose 6 headers :

• Cache-Control
• Content-Language
• Content-Type Expires
• Last-Modified & Pragma.

In order to access custom headers with a CORS request, the server has to explicitly whitelist them. This can be done by sending the response header: Access-Control-Expose-Headers

Java : addExposedHeader https://docs.spring.io/spring-framework/docs/4.2.x/javadoc-api/org/springframework/web/cors/CorsConfiguration.html

.NET CORE : WithExposedHeaders https://docs.microsoft.com/en-us/aspnet/core/security/cors?view=aspnetcore-6.0

Express JS : exposedHeaders https://expressjs.com/en/resources/middleware/cors.html