Question

我的应用中有多项服务，例如AuthenticateService，UserService，可以从API请求数据。

在大多数服务功能中都有一些常用标头，例如authentication token和Content-Type header。我想将这些标题保留在单个类中，并在请求数据时在服务中使用它们。

我尝试创建一个custom export class并通过在其中定义函数来获取这些函数，但它会产生一些错误。 Angular 2/4

从服务中访问的类

import { Injectable } from '@angular/core'; 


import { Http, Headers, Response, RequestOptions } from '@angular/http';
@Injectable()
export class MainService {

    commonHeaders(){
        let headers = new Headers({  
            'Content-Type': 'application/json',
        });
        return headers; 
    }

    AuthorizedRequestCommonHeaders() {
        let headers = new Headers({  
            'Content-Type': 'application/json',
        });
        headers.append('Authorization', 'Basic ' + (localStorage.getItem('auth_token')) ); 
        return headers;
    } 

}

我尝试访问如下 AuthenticationService.ts

import { Injectable } from '@angular/core';
import { Http, Headers, Response, RequestOptions } from '@angular/http';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/operator/map'

import { MainService } from './main-service';  

@Injectable()
export class AuthenticationService {
  login(email: string, password: string) {
    let headers = this.MainService.commonHeaders();
    let options = new RequestOptions({
        headers: headers
    });

    let postData = {  
        email: email,
        password: password  
    }

    return this.http.post(this.oauthUrl, JSON.stringify(postData) , options)
        .map((response: Response) => { 
            let result = response.json(); 
            if (result && result.token) { 
                localStorage.setItem('auth_token', JSON.stringify(result.token)); 
            }
        });

}

错误消息

属性'commonHeaders'在'MainService'类型上不存在。

Answer 1

通过导入它可以在任何地方使用的通用功能

import { Injectable } from '@angular/core';     
import { Http, Headers, Response, RequestOptions } from '@angular/http';
@Injectable()
export class MainService {



    AuthorizedRequestCommonHeaders() {
        let headers = commonHeaders();
        headers.append('Authorization', 'Basic ' + (localStorage.getItem('auth_token')) ); 
        return headers;
    } 

}

export function commonHeaders(){ //keep this is main service or any other but make sure to provide proper path
            let headers = new Headers({  
                'Content-Type': 'application/json',
            });
            return headers; 
        }

AuthenticationService.ts

import { commonHeaders } from './main-service'; 

@Injectable()
export class AuthenticationService {
  login(email: string, password: string) {
    let headers = commonHeaders();
}

保留常用标题并在角度2/4中使用多个服务

1 个答案: