Angular: HttpInterceptor with different handling for specific situation

Question

I know there is in Angular the HTTPInterceptor:

@Injectable()
export class HTTPRequestInterceptor implements HttpInterceptor {

intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    return next.handle(request).pipe(
      tap(
        (_response: HttpEvent<any>) => {
          // nothing to do ... ... used for sending anyway...
        },
        (error: HttpErrorResponse) => {
         ... // display message
        }

To my understanding this is applied to all of my requests. Now I have the situation that for one specific request I do not want to apply the regular error handling. Is there an easy way to achieve this? e.g. setting some special parameters in my request

this.http.get<MyInfo>(`getlastInfo/${id}`).toPromise();

Answer 1

As BELLIL suggested, reading a header is easier than relying on the url. You could still remove the header before sending it to the server :

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

    const doSpecificHandling = req.headers.has('Angular-Error-Handler');

    return next.handle(req.clone({
      headers: req.headers.delete('Angular-Error-Handler')
    })).pipe(
      tap(
        (_response: HttpEvent<any>) => {
          // nothing to do ... ... used for sending anyway...
        },
        (error: HttpErrorResponse) => {
          if (doSpecificHandling) {
            //handle error for specific case
          } else {
            //handle error for generic case
          }
        }
      )
    );
  }

With the request:

this.http.get<MyInfo>(`getlastInfo/${id}`, {
  headers: new HttpHeaders().set('Angular-Error-Handler', 'diff'),
}).toPromise();