Ionic2 Http requests

Ionic Http Requests.js

import {Injectable, EventEmitter} from 'angular2/core';
import {Http, Headers, RequestOptions, RequestOptionsArgs, Response, RequestMethod, Request, Connection, ConnectionBackend} from 'angular2/http';
import * as Rx from 'rxjs';


export enum Action { QueryStart, QueryStop };

@Injectable()
export class AuthHttp {
  process: EventEmitter<any> = new EventEmitter<any>();
  authFailed: EventEmitter<any> = new EventEmitter<any>();

  constructor(private _http: Http) { }

  private _buildAuthHeader(): string {
    return localStorage.getItem("authToken");
  }

  public get(url: string, options?: RequestOptionsArgs): Rx.Observable<Response> {
    return this._request(RequestMethod.Get, url, null, options);
  }

  public post(url: string, body: string, options?: RequestOptionsArgs): Rx.Observable<Response> {
    return this._request(RequestMethod.Post, url, body, options);
  }

  public put(url: string, body: string, options?: RequestOptionsArgs): Rx.Observable<Response> {
    return this._request(RequestMethod.Put, url, body, options);
  }

  public delete(url: string, options?: RequestOptionsArgs): Rx.Observable<Response> {
    return this._request(RequestMethod.Delete, url, null, options);
  }

  public patch(url: string, body: string, options?: RequestOptionsArgs): Rx.Observable<Response> {
    return this._request(RequestMethod.Patch, url, body, options);
  }

  public head(url: string, options?: RequestOptionsArgs): Rx.Observable<Response> {
    return this._request(RequestMethod.Head, url, null, options);
  }

  private _request(method: RequestMethod, url: string, body?: string, options?: RequestOptionsArgs): Rx.Observable<Response> {
    let requestOptions = new RequestOptions(Object.assign({
      method: method,
      url: url,
      body: body
    }, options));

    if (!requestOptions.headers) {
      requestOptions.headers = new Headers();
    }

    requestOptions.headers.set("Authorization", this._buildAuthHeader())

    return Rx.Observable.create((observer) => {
      this.process.next(Action.QueryStart);
      this._http.request(new Request(requestOptions))
        .map(res=> res.json())
        .finally(() => {
        this.process.next(Action.QueryStop);
      })
        .subscribe(
        (res) => {
          observer.next(res);
          observer.complete();
        },
        (err) => {
          switch (err.status) {
            case 401:
              //intercept 401
              this.authFailed.next(err);
              observer.error(err);
              break;
            default:
              observer.error(err);
              break;
          }
        })
    })
  }
}