Token HttpInterceptor

token.interceptor.ts

import {Injectable} from '@angular/core';
import {HttpEvent, HttpHandler, HttpInterceptor, HttpRequest} from '@angular/common/http';
import {Observable} from 'rxjs/Observable';
import {AuthService} from '../services/auth.service';


@Injectable()
export class TokenInterceptor implements HttpInterceptor {

  constructor(private auth: AuthService) {
  }

  intercept(request: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    const token = localStorage.getItem('token'); // Without Auth Service
//  const token = this.auth.getToken(); // With Auth Service (AuthService is custom service which u can create)

    if (token) {
      request = request.clone({
        setHeaders: {
          authToken: `Bearer ${token}`
        }
      });
    }

    return next.handle(request);
  }
}