如何确定控制器是否应该使用wantsJSON返回JSON

Question

我在sails中看到请求对象中有一个名为wantsJSON的变量，并且在创建新项目时生成的错误页面中显示

if (req.wantsJSON) {
    //Do Something
} 

sails如何决定用户是否想要JSON？

Answer 1

Sails根据请求决定。您可以在the source code中找到它。我已经复制并评论了有趣的部分：

// True, if the request has a xhr polling origin. (via socket)
req.wantsJSON = req.xhr;

// True, if the above was false (or null) and the origin not only accepts html.
// See HTTP header field 'Accept'
req.wantsJSON = req.wantsJSON || !req.explicitlyAcceptsHTML;

// True, if everything above was false (or null) and the origins content type 
// is json and the header field 'Accept' is set.
// See HTTP header field 'Content-type'
req.wantsJSON = req.wantsJSON || (req.is('json') && req.get('Accept'));