import { Injectable } from '@angular/core';
import { HttpRequest, HttpHandler, HttpEvent, HttpInterceptor, HttpErrorResponse } from '@angular/common/http';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/operator/catch';
import 'rxjs/add/observable/throw';

 @Injectable()
 export class AddHeaderInterceptor implements HttpInterceptor {
     intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {

    let currentUser = JSON.parse(localStorage.getItem('currentUser'));
    if (currentUser && currentUser.token) {
        request = request.clone({
            setHeaders: {
                Authorization: `Bearer ${currentUser.token}`,
                Ip:currentUser.Ip
            }
        });
    }
    return next.handle(request);
}
}

import { HTTP_INTERCEPTORS } from '@angular/common/http';

@NgModule({
   providers: [{
   provide: HTTP_INTERCEPTORS,
   useClass: AddHeaderInterceptor,
   multi: true,
  }],
})
export class AppModule {}