Mark code 1

naive.js

// User ID
var _id;

// Facebook ready
window.fbAsyncInit = function() {
    FB.init({ appId: 'XXX' });
    
    // Do we have a user?
    FB.getLoginStatus(function(response) {
        if('connected' === response.status) {
            // Save user ID
            _id = response.authResponse.userID;
        }
    });
};

// Page ready, get user from Kinvey
window.onload = function() {
    // NOTE at this point, it is unsure whether FB.getLoginStatus has terminated
    kinvey.user.fetch(_id, function(user) {
        // User found, go ahead and render page
    });
};