Using Omniauth facebook and ajax - ruby-on-rails

Question

I'm trying to allow a user to sign in via facebook, and not be redirected off of the current page. I'm currently using Rails with omniauth-facebook and devise for authentication. I'm assuming the best way to do this is via ajax once I've received authentication from facebook via the Javascript api. However, I'm not sure what I need to pass to the callback url for omniauth to verify the authentication. Here's what I currently have (I'm trying to avoid using jquery for the time being)
:javascript
window.fbAsyncInit = function() {
// init the FB JS SDK
FB.init({
appId : 'app-id', // App ID from the app dashboard
channelUrl : '//localhost:3000/channel.html', // Channel file for x-domain comms
status : true, // Check Facebook Login status
cookie : true,
xfbml : true // Look for social plugins on the page
});
// Additional initialization code such as adding Event Listeners goes here
document.getElementById('facebook-login').onclick = function(event) {
FB.login(function(response) {
if (response.authResponse) {
var xhr = new XMLHttpRequest();
xhr.onreadystatechange = function() {
console.log(xhr);
if (xhr.readyState == 4) {
console.log(xhr.responseText);
}
}
xhr.open('GET', 'http://localhost:3000/users/auth/facebook/callback', true);
xhr.send(null);
} else {
console.log("Something when horrible wrong");
}
}, {scope: ''});
}
};
// Load the SDK asynchronously
(function(d, s, id){
var js, fjs = d.getElementsByTagName(s)[0];
if (d.getElementById(id)) {return;}
js = d.createElement(s); js.id = id;
js.src = "//connect.facebook.net/en_US/all.js";
fjs.parentNode.insertBefore(js, fjs);
}(document, 'script', 'facebook-jssdk'));
The thing I'm most unsure about is if I'm calling my own endpoint (users/auth/facebook/callback) correctly, or if I need to pass anything to it. Any help would be greatly appreciated.

Answer 1

For me, the problem was making a GET request instead of a POST request.
Changed to POST and the problem is gone.
I would have left it as a comment, as I'm not leaving further information to justify this solution, but i'm new at this (StackOverflow); I don't have enough points to be able to comment.
Anyway, Hope it helps!