XDomain 详细介绍
XDomain 是 JavaScript CORS 跨域请求的一个替代产品，无需任何服务器端的配置。只需要在同域下放置一个 proxy.html 文件即可。该库利用 XHook 来获取所有 XHR，可以无缝的和其他库协同工作。

Features

• Simple

• Library Agnostic

  • With jQuery $.ajax (and subsequently $.get, $.post)
  • With Angular $http service

• Cross domain XHR just magically works

  • No need to modify the server code
  • No need to use IE's silly XDomainRequest Object

• Easy XHR access to file servers:

  • Amazon
  • Dropbox
• Includes XHook and its features

• proxy.html files (slaves) may:

  • White-list domains
  • White-list paths using regular expressions (e.g. only allow API calls: /^/api/)
• Highly performant
• Seamless integration with FormData

示例代码：

//do some vanilla XHR
var xhr = new XMLHttpRequest();
xhr.open('GET', 'http://xyz.example.com/secret/file.txt');
xhr.onreadystatechange = function(e) {
  if(xhr.readyState === 4)
    alert(xhr.responseText);
};
xhr.send();

//or if we are using jQuery...
$.get('http://xyz.example.com/secret/file.txt').done(function(data) {
  console.log("got result: ", data);
});