使用Express在NodeJS上检测AJAX请求

Question

I'm using NodeJS with Express. How can I tell the difference between an ordinary browser request and an AJAX request? I know I could check the request headers but does Node/Exprsss expose this information?

Answer 1

Most frameworks set the X-Requested-With header to XMLHttpRequest , for which Express has a test:

app.get('/path', function(req, res) {
  var isAjaxRequest = req.xhr;
  ...
});

Answer 2

In case the req.xhr is not set, say in frameworks such as Angularjs, where it was removed , then you should also check whether the header can accept a JSON response (or XML, or whatever your XHR sends as a response instead of HTML).

if (req.xhr || req.headers.accept.indexOf('json') > -1) {
  // send your xhr response here
} else {
  // send your normal response here
}

Of course, you'll have to tweak the second part a little to match your usecase, but this should be a more complete answer.

Ideally, the angular team should not have removed it, but should have actually found a better solution for the CORS' pre-flight problem, but that's how it rests now...