angular-facebook.js

angular.module('Facebook', [])
.factory('Facebook', function($rootScope, $q){
  var facebook = {};

  /**
   * @name facebook.getPermission
   * @requires $q
   *
   * @description
   * Try to receive permissions from Facebook.
   *
   * @param {string} permission The identifier of the permissions to request,
   *   see <https://developers.facebook.com/docs/reference/login/#permissions>
   * @returns {Promise} Promise will be resolved with Object containing
   *   `permission_granted` (bool) and possible also `uid` and `accessToken`,
   *   or rejected with Object containing `permission_granted: false`.
   */
  facebook.getPermission = function(permission) {
    var deferred = $q.defer();
    var promise = deferred.promise;

    FB.getLoginStatus(function(response) {
      if(response.authResponse) {
        FB.api('/me/permissions', function(perms_response) {
          if(perms_response['data'][0][permission]) {
            $rootScope.$apply(function() {
              deferred.resolve({
                permission_granted: true
              });
            });
          } else {
            FB.login(function(response) {
              if(response.authResponse) {
                $rootScope.$apply(function() {
                  deferred.resolve({
                    permission_granted: true,
                    uid: response.authResponse.userID,
                    accessToken: response.authResponse.accessToken
                  });
                });
              } else {
                $rootScope.$apply(function() {
                  deferred.reject({
                    permission_granted: false
                  });
                });
              }
            }, {scope: permission});
          }
        });
      } else {
        FB.login(function(response) {
          if(response.authResponse) {
            $rootScope.$apply(function() {
              deferred.resolve({
                permission_granted: true,
                uid: response.authResponse.userID,
                accessToken: response.authResponse.accessToken
              });
            });
          } else {
            $rootScope.$apply(function() {
              deferred.reject({
                permission_granted: false
              });
            });
          }
        }, {scope: permission});
      }
    });

    return promise;
  };

  facebook.init = function() {
    var deferred = $q.defer();

    FB.getLoginStatus(function(response) {
      if (response.status === 'connected') {
        /*
        The user is logged in and connected to your app, and
        `response.authResponse` supplies:

        * user's ID
        * a valid access token
        * a signed request

        and the time the access token and signed request each expire.
        */
        $rootScope.$apply(function() {
          deferred.resolve({
            status: response.status,
            uid: response.authResponse.userID,
            accessToken: response.authResponse.accessToken
          });
        });
      } else if (response.status === 'not_authorized') {
        /*
        The user is logged in to Facebook, but not connected to the app.
        */
        $rootScope.$apply(function() {
          deferred.resolve({
            status: response.status
          });
        });
      } else {
        /*
        The user isn't even logged in to Facebook.
        */
        $rootScope.$apply(function() {
          deferred.reject({
            status: 'not_facebook_user'
          });
        });
      }
    });

    return deferred.promise;
  };

  return facebook;
})
;