CORS in Node.js and AngularJS - node.js

Question

I have a CORS problem with my app.
My stack is Node.js with Express 4 and AngularJS using Restangular
I already have tried a few things (for example) but I keep getting:
XMLHttpRequest cannot load http://localhost:8080/api/users. Request header field Content-Type is not allowed by Access-Control-Allow-Headers.
In the server side I have this headers:
app.all('/*', function(req, res, next) {
res.header("Access-Control-Allow-Origin", "*");
res.header("Access-Control-Allow-Headers", "X-Requested-With");
res.header("Access-Control-Allow-Methods", "GET, POST","PUT");
next();
});
In the AngularJS part I am using this:
$httpProvider.defaults.useXDomain = true;
delete $httpProvider.defaults.headers.common['X-Requested-With'];
And I am doing the post with Restangular like this:
var baseUsers = Restangular.all('users');
....
....
baseUsers.post(newUser).then(function(user){
console.log(user);
});
One more thing, in the Node.js server I am consoling the req.method and it says OPTIONS, I really don't know why.
Perhaps is something silly, hope someone can help me.
Thanks!

Answer 1

Change -
res.header("Access-Control-Allow-Headers", "X-Requested-With");
TO
res.header("Access-Control-Allow-Headers", "X-Requested-With, Content-Type");
Source 1
Source 2

Answer 2

I am posting same answer with a detailed code, Because i got some issues when i use the selected answer.
Just pull the code below after initialization of the app object
app.all('/*', function(req, res, next) {
res.header("Access-Control-Allow-Origin", "*");
res.header("Access-Control-Allow-Headers", "X-Requested-With, Content-Type");
res.header("Access-Control-Allow-Methods", "GET, POST","PUT");
next();
});
I hope this will be little bit more helpful.