javascript - 如何通过jsonp读取cookie？

Question

嗨，我有这段代码可以从index.html加载页面:

<script src="https://ajax.aspnetcdn.com/ajax/jQuery/jquery-1.12.2.min.js"></script>
<script>
function jsonCallback(json){
  console.log(json);
  alert(document.cookie.json)
}

$.ajax({
  url: "https://run.plnkr.co/plunks/v8xyYN64V4nqCshgjKms/data-2.json",
  dataType: "jsonp"
});
</script>

我想要获取cookie，所以在https://run.plnkr.co/plunks/v8xyYN64V4nqCshgjKms/data-2.json我已在控制台中执行: document.cookie='test=123' 并返回未定义。为什么？我该如何修复它？

以下是该 URL 返回的内容:

jsonCallback(
  {
    "sites":
    [
      {
        "siteName": "SitePoint",
        "domainName": "https://www.sitepoint.com",
        "description": "SitePoint is a hub for web developers to share their passion for building incredible Internet things."
      },
      {
        "siteName": "A List Apart",
        "domainName": "http://alistapart.com/",
        "description": "A List Apart explores the design, development, and meaning of web content, with a special focus on web standards and best practices."
      },
      {
        "siteName": "Smashing Magazine",
        "domainName": "https://www.smashingmagazine.com/",
        "description": "Smashing Magazine delivers useful and innovative information to Web designers and developers."
      }
    ]
  }
);

Answer 1

您不能在页面中使用 JavaScript 代码来读取其他来源的 cookie。如果您有 http://example.com/foo.html 并在其中加载来自 http://api.com 的脚本(这就是您使用 JSONP 所做的事情)/，随来自 http://api.com/ 的响应返回的任何 cookie 都与 http://api.com/ 关联。您无法使用 http://example.com/foo.html 中的 JavaScript 代码读取它们。