( Editor: VS Code; Typescript: 2.2.1 )
The purpose is to get the headers of the response of the request
Assume a POST request with HttpClient in a Service
import {
Injectable
} from "@angular/core";
import {
HttpClient,
HttpHeaders,
} from "@angular/common/http";
@Injectable()
export class MyHttpClientService {
const url = 'url';
const body = {
body: 'the body'
};
const headers = 'headers made with HttpHeaders';
const options = {
headers: headers,
observe: "response", // to display the full response
responseType: "json"
};
return this.http.post(sessionUrl, body, options)
.subscribe(response => {
console.log(response);
return response;
}, err => {
throw err;
});
}
HttpClient Angular Documentation
The first problem is that I have a Typescript error :
'Argument of type '{
headers: HttpHeaders;
observe: string;
responseType: string;
}' is not assignable to parameter of type'{
headers?: HttpHeaders;
observe?: "body";
params?: HttpParams; reportProgress?: boolean;
respons...'.
Types of property 'observe' are incompatible.
Type 'string' is not assignable to type '"body"'.'
at: '51,49' source: 'ts'
Indeed, when I go to the ref of post() method, I point on this prototype (I Use VS code)
post(url: string, body: any | null, options: {
headers?: HttpHeaders;
observe?: 'body';
params?: HttpParams;
reportProgress?: boolean;
responseType: 'arraybuffer';
withCredentials?: boolean;
}): Observable<ArrayBuffer>;
But I want this overloaded method :
post(url: string, body: any | null, options: {
headers?: HttpHeaders;
observe: 'response';
params?: HttpParams;
reportProgress?: boolean;
responseType?: 'json';
withCredentials?: boolean;
}): Observable<HttpResponse<Object>>;
So, I tried to fix this error with this structure :
const options = {
headers: headers,
"observe?": "response",
"responseType?": "json",
};
And It compiles! But I just get the body request as in json format.
Futhermore, why I have to put a ? symbol at the end of some name of fields ? As I saw on Typescript site, this symbol should just tell to the user that it is optional ?
I also tried to use all the fields, without and with ? marks
EDIT
I tried the solutions proposed by Angular 4 get headers from API response. For the map solution:
this.http.post(url).map(resp => console.log(resp));
Typescript compiler tells that map does not exists because it is not a part of Observable
I also tried this
import { Response } from "@angular/http";
this.http.post(url).post((resp: Response) => resp)
It compiles, but I get a unsupported Media Type response. These solutions should work for "Http" but it does not on "HttpClient".
EDIT 2
I get also a unsupported media type with the @Supamiu solution, so it would be an error on my headers. So the second solution from above (with Response type) should works too. But personnaly, I don't think it is a good way to mix "Http" with "HttpClient" so I will keep the solution of Supamiu
You can observe the full response instead of the content only. To do so, you have to pass observe: response
into the options
parameter of the function call.
http
.get<MyJsonData>('/data.json', {observe: 'response'})
.subscribe(resp => {
// Here, resp is of type HttpResponse<MyJsonData>.
// You can inspect its headers:
console.log(resp.headers.get('X-Custom-Header'));
// And access the body directly, which is typed as MyJsonData as requested.
console.log(resp.body.someField);
});