Error No Access-Control-Allow-Origin header is present on the requested resource node js

Question

I have a problem when trying to communicate with my node.js server from ajax requests.

I have configured my server like this :

var allowCrossDomain = function(req, res, next) {
  res.header("Access-Control-Allow-Origin", "*");
  res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type,      Accept");
  next();
};

app.use(allowCrossDomain);

When doing my requests I have this error :

XMLHttpRequest cannot load http://10.192.122.180:8181/meters. No 'Access-Control-Allow-     Origin' header is present on the requested resource. Origin 'http://localhost:6161' is  therefore not allowed access.

Could someone help me please ?

Thanks!

Answer 1

Hello @kartik,

My guess is that you're serving the page before your middleware (allowCrossDomain) gets a chance to run.

If you're using Express 3, try the following:

app.use(allowCrossDomain);
app.use(app.router);

If you're using Express 4, make sure your app.use(allowCrossDomain) call is before the rest of your routes (app.get and such).

Hope it helps!