Facebook connect for Windows 8 metro style apps

request_fb_token.js

/**
 * Ask user for facebook connect & get the accesstoken
 *
 * @param {Object} options
 * @param {Function} callback
 * @param {Function} error_handler (optional)
 **/
function requestFbToken (options, callback, error_handler) {
    options = _extend({
        appId: null,
        redirectUri: 'https://www.facebook.com',
        scope: [],
        display: 'popup'
    }, options);

    if (options.appId === null) {
        throw new Error('require app id');
    }

    if (typeof callback !== 'function') {
        throw new Error('require callback function');
    }

    if (typeof error_handler !== 'undefined' &&
        typeof error_handler !== 'function') {
        throw new Error('error handler should be a function');
    }
    error_handler = error_handler || function (e) { console.log(e, e.stack); };

    var auth_uri = 'https://www.facebook.com/dialog/oauth?' + 
                   'client_id=' + options.appId +
                   '&redirect_uri=' + encodeURIComponent(options.redirectUri) + 
                   '&scope=' + options.scope.join(',') +
                   '&display=' + options.display +
                   '&response_type=token',
        callback_uri = options.redirectUri;

    Windows.Security.Authentication.Web.WebAuthenticationBroker.authenticateAsync(
        Windows.Security.Authentication.Web.WebAuthenticationOptions.none,
        new Windows.Foundation.Uri(auth_uri),
        new Windows.Foundation.Uri(callback_uri)
    )
    .done(function (result) {
        var m = result.responseData.match(/#access_token=(.+?)&/);

        callback(m === null ? m : m[1]);
    }, error_handler);

    function _extend(d, s) {
        for (var property in s) {
            d[property] = s[property];
        }
        return d;
    }
};