为什么在CodeIgniter rest-server中，访问控制 - 甘应 - 原始蛋白不起作用

Question

我想从一个区块链API中获取数据..

在控制器cart.php

中

<?php
defined('BASEPATH') OR exit('No direct script access allowed');
class Cart extends CI_Controller {
    /**
     * Index Page for this controller.
     *
     * Maps to the following URL
     *      http://example.com/index.php/welcome
     *  - or -
     *      http://example.com/index.php/welcome/index
     *  - or -
     * Since this controller is set as the default controller in
     * config/routes.php, it's displayed at http://example.com/
     *
     * So any other public methods not prefixed with an underscore will
     * map to /index.php/welcome/<method_name>
     * @see https://codeigniter.com/user_guide/general/urls.html
     */
    public function __construct()
    {
        parent::__construct();
        header("Access-Control-Allow-Methods: GET, OPTIONS");
        header("Access-Control-Allow-Headers: Content-Type, Content-Length, Accept-Encoding");
        if ( "OPTIONS" === $_SERVER['REQUEST_METHOD'] ) {
        die();
        }
    }
    public function index()
    {
        $this->load->view('cart_view');
    }
}

in asyc.js

$.getJSON( "https://blockchain.info/rawaddr/1N1WJYDUgaBrk9eUfawSYurs9ZtKcVVfTE", function( data ) {
  console.log(data);
});

我有错误

XMLHttpRequest cannot load https://blockchain.info/rawaddr/1N1WJYDUgaBrk9eUfawSYurs9ZtKcVVfTE. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://localhost' is therefore not allowed access.

Answer 1

您误解了CORS的工作原理。您已将CORS标头添加到您自己的代码中，而标头需要从Blockchain.info输出。

某些区块链API调用可以附加&cors=true以获取CORS标题，但不能将其提供此特定端点。

解决方案是通过自己的服务器端代理您的API调用。在PHP代码中创建一个将调用区块链API的路由。服务器到服务器请求将不受CORS的约束。通过Ajax致电您的PHP路线。