How to retrieve the facebook oauth 2.0 access_token - facebook

Question

I am trying to get the access_token of the logged in facebook user.
I get something like this.. url followed by the code i am retrieve the code..
it says in the guide to exchange it for access_token...
https://graph.facebook.com/oauth/access_token?
client_id=XXXXXXXXXXXXXX&
redirect_uri=http://www.my-site.com/&
client_secret=XXXXXXXXXXXXXXXXXXXXX&
code=2.hJFWoMlLf3tLOSos_qNCBg__.3600.1279836000-10000100XXXXXXX|kGwPB4y5K_-ijD9_1CfjSpT-oaY..
How i can exchange it for a access_token using what FB.api or jquery or javascript..
When i plug this url in the address bar.. i am able to see access_token..
I appreciate if somebody can tell me how to retrieve the access_token using javascript or jquery.
Thanks.

Answer 1

According to Facebook, and my personal experiences with the api, the FB.getSession() function is deprecated and should throw an exception if called.
From facebook:
The FB.getAuthResponse method is a replacement for the FB.getSession method which was deprecated after the migration to OAuth 2.0.
Instead you should use the getLoginStatus callback -
FB.getLoginStatus(function(response) {
var token = response.authResponse.accessToken;
});
//Example structure of response object
var eg =
{
status: 'connected',
authResponse: {
accessToken: '...',
expiresIn:'...',
signedRequest:'...',
userID:'...'
}
};
source: http://developers.facebook.com/docs/reference/javascript/FB.getLoginStatus/

Answer 2

If you are using the JavaScript SDK, then after logging in the user, getting the access token in your JavaScript code is as simple as:
FB.getSession().access_token
However, getSession may return null if a user is logged out, so the proper way is to first check for null before accessing the token.
var session = FB.getSession();
if(session != null) { // user is still logged in
console.log(session.access_token);
}