ruby-on-rails - Rails 3 应用程序中的 Access-Control-Allow-Origin 不允许来源 http://localhost:3000

Question

我无法通过以下错误从 XHR 获取 GET

XMLHttpRequest cannot load http://blog.rrikesh.com/demo/assets/img/img1.jpg. Origin       
http://localhost:3000 is not allowed by Access-Control-Allow-Origin.

所以，我允许这样的跨域访问：

class ApplicationController < ActionController::Base
  protect_from_forgery
  before_filter :allow_cross_domain_access
  def allow_cross_domain_access
      response.headers["Access-Control-Allow-Origin"] = "*"
      response.headers["Access-Control-Allow-Methods"] = "GET, PUT, POST, DELETE"
  end
end

但是，它会发生同样的错误。我能做些什么？

Answer 1

以下 PHP 代码适用于我。请注意 if (...) 非常重要，如果您为所有请求返回相同的 CORES 标头，那么（至少）chrome 将取消请求（至少对于 localhost 服务器）

<?php
if (isset($_SERVER['HTTP_ORIGIN'])) {
    //header("Access-Control-Allow-Origin: {$_SERVER['HTTP_ORIGIN']}");
    header("Access-Control-Allow-Origin: *");
    header('Access-Control-Allow-Credentials: true');    
    header("Access-Control-Allow-Methods: GET, POST, OPTIONS"); 
}   
if ($_SERVER['REQUEST_METHOD'] == 'OPTIONS') {
    if (isset($_SERVER['HTTP_ACCESS_CONTROL_REQUEST_METHOD']))
        header("Access-Control-Allow-Methods: GET, POST, OPTIONS");         
    if (isset($_SERVER['HTTP_ACCESS_CONTROL_REQUEST_HEADERS']))
        header("Access-Control-Allow-Headers: {$_SERVER['HTTP_ACCESS_CONTROL_REQUEST_HEADERS']}");

    exit(0);
} 

?>