javascript - 从 HTML 脚本向另一个域中的 Node.JS 应用程序发出 POST JSON 请求

Question

我正在尝试通过 .erb.html 文件内的 javascript 发出 post json 请求，将字符串数据发送到另一个域中的 node.js 应用程序，该应用程序使用 Express 来处理传入请求。

我从几篇文章中读到，仅使用 XMLHttpRequest 是不可能做到这一点的。如何向这样的应用程序发送这样的请求？

Answer 1

要使用 XMLHttpRequest 执行此操作，远程服务器必须配置 CORS header 。

From MDN :

A resource makes a cross-origin HTTP request when it requests a resource from a different domain, protocol, or port to its own. For example, an HTML page served from http://domain-a.com makes an src request for http://domain-b.com/image.jpg. Many pages on the web today load resources like CSS stylesheets, images, and scripts from separate domains.

For security reasons, browsers restrict cross-origin HTTP requests initiated from within scripts. For example, XMLHttpRequest and Fetch follow the same-origin policy. So, a web application using XMLHttpRequest or Fetch could only make HTTP requests to its own domain. To improve web applications, developers asked browser vendors to allow cross-domain requests.