http.service.ts

import { InjectionToken } from '@angular/core';
import { HttpClient, HttpEvent, HttpInterceptor, HttpHandler, HttpRequest } from '@angular/common/http';
import { Observable } from 'rxjs';

declare module '@angular/common/http/src/client' {

  export interface HttpClient {
    hideLoader(hide?: boolean): HttpClient;
  }

}

class HttpInterceptorHandler implements HttpHandler {

  constructor(private next: HttpHandler, private interceptor: HttpInterceptor) { }

  handle(request: HttpRequest<any>): Observable<HttpEvent<any>> {
    return this.interceptor.intercept(request, this.next);
  }

}

export const HTTP_DYNAMIC_INTERCEPTORS = new InjectionToken<HttpInterceptor>('HTTP_DYNAMIC_INTERCEPTORS');