Facebook Single Sign-on App

In this page, you will learn how to use Facebook’s Single Sign-On (SSO) with Monaca Cloud IDE using Angular 1 and Onsen UI. The authentication is done by cordova-plugin-facebook4. This plugin will use the native Facebook app to perform Single Sign On for the user; otherwise, the sign on will degrade gracefully using the standard dialog based authentication.

Tested Environment

  • Android 7.0
  • iOS 10.1.1

Prerequisite

APP_ID and APP_NAME are required by the cordova-plugin-facebook4 plugin. These two values can be found in the Facebook for Developer console after registering your app. To do so, please proceed as follows:

  1. Go to Facebook for Developers and log in with your Facebook account.

  2. Go to My Apps → Add a New App .

  3. Input the necessary information of your app and click Create App ID.

  4. From the Dashboard, go to Settings and you will be able to find the APP_ID (App ID) and APP_NAME (Display Name).

  5. Now it’s time to add the platform(s) of the devices which will run your app by clicking + Add Platform button.

  6. If your app will run on Android, select Android.

  7. Fill in the necessary information as shown below and click Save Changes:

    • Google Play Package Name: is the Android’s Package Name you configured in Monaca Cloud IDE for Android App Settings.

    • Key Hashes: is the SHA-1 fingerprint of the KeyStore you configured in Monaca Cloud IDE for Android KeyStore Settings. Please refer to How to get SHA-1 fingerprint of a keystore created in Monaca Cloud IDE.

    • Enable Single Sign On option.

  8. If your app will run on iOS as well, Click + Add Platform and select iOS.

  9. Fill in the necessary information as shown below and Save Changes:

    • Bundle ID: is the iOS’s App ID you configured in Monaca Cloud IDE for iOS App Settings.

    • Enable Single Sign On option.

Importing the Project to Monaca Cloud IDE

Configuring the Plugin

The authentication is done by cordova-plugin-facebook4. This plugin will use the native Facebook app to perform Single Sign-on for the user; otherwise, the sign on will degrade gracefully using the standard dialog based authentication.

Before starting to use the plugin, you are required to input the APP_ID and APP_NAME values within the plugin’s configuration as follows:

  1. From Monaca Cloud IDE menu, go to Configure → Cordova Plugin Settings .

  2. Under the Enabled Plugins section, hover over cordova-plugin-facebook4 and click Configure button.

  3. Input the APP_ID and APP_NAME values you got in the Prerequisite section. See the screenshot below as an example:

  4. Click OK to complete the configuration.

Application Explanation

File Components

File Description
index.html The startup Page
home.html Login Page
profile.html User profile Page
css/style.css A stylesheet file for the application
js/app.js A JavaScript file for implementation of the application

HTML Explanation

index.html

<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no">
<meta http-equiv="Content-Security-Policy" content="default-src * data:; style-src * 'unsafe-inline'; script-src * 'unsafe-inline' 'unsafe-eval'">
<script src="components/loader.js"></script>
<script src="lib/angular/angular.min.js"></script>
<script src="lib/onsenui/js/onsenui.min.js"></script>
<script src="lib/onsenui/js/angular-onsenui.min.js"></script>
<script src="js/app.js"></script>

<link rel="stylesheet" href="components/loader.css">
<link rel="stylesheet" href="lib/onsenui/css/onsenui.css">
<link rel="stylesheet" href="lib/onsenui/css/onsen-css-components.css">
<link rel="stylesheet" href="css/style.css">
</head>
<body>
  <body >
      <ons-navigator id="myNavigator" page="home.html"></ons-navigator>
  </body>
</body>
</html>

This file is the startup page of the application. As you can see within the <body> tag, there is only one ons-navigator component. It provides page stack management and navigation. The attribute page is used to identify the first page in the stack.

home.html

<ons-page ng-controller="HomeCtrl">
  <ons-toolbar>
      <div class="center">Facebook Demo</div>
  </ons-toolbar>
  <div class="page">
      <p class="center">
          Welcome to Facebook Authentication Demo with Monaca using Onsen UI and AngularJS!
      </p>
      <ons-button ng-click="Login()">
          Connect to Facebook
      </ons-button>
  </div>
</ons-page>

This page is a login page. If there is existing login information found in the device, it will be automatically redirected to profile.html page.

profile.html

<ons-page ng-controller="ProfileCtrl">
  <ons-toolbar>
      <div class="center">Facebook Profile</div>
      <div class="right">
          <ons-toolbar-button ng-click="Logout()">
              <ons-icon icon="fa-sign-out"></ons-icon>
          </ons-toolbar-button>
      </div>
  </ons-toolbar>
  <div class="page">
      <p class="center">
          <img src="{{user.profile_url}}" class="profile">
          <p>{{user.name}}</p>
          <p>(@{{user.id}})</p>
          <p>{{user.email}}</p>
      </p>
  </div>
</ons-page>

This page is a user’s Facebook profile page.

Stylesheet Explanation

This file consists of the CSS style for the navigation bar and Facebook profile image.

div.page {
 padding: 5%;
 text-align: center;
}

p.center {
  text-align: center;
}

img.profile {
  width: 40%;
  border: solid 1px #1da1f2;
  border-radius: 5px;
}

.navigation-bar {
  background-color: #4267b2;
}

.button {
  background-color: #4267b2;
}

JavaScript Explanation

ons.bootstrap()
.service('StorageService', function() {
  var setLoginUser = function(user_info) {
      window.localStorage.login_user = JSON.stringify(user_info);
  };

  var getLoginUser = function(){
      return JSON.parse(window.localStorage.login_user || '{}');
  };

  return {
      getLoginUser: getLoginUser,
      setLoginUser: setLoginUser
  };
})

.controller('HomeCtrl', function($scope, StorageService, $http, $q) {
  var CheckLoginStatus = function(){
      window.facebookConnectPlugin.getLoginStatus(
          function(data){
              if(data.authResponse){
                  console.log('Login info is found!');
                  myNavigator.pushPage('profile.html');
              }else{
                  console.log('No login info is found!');
              }
          },
          function(e){
              LoginError(e);
          }
      );
  }

  ons.ready(function() {
      CheckLoginStatus();
  });

  var GetProfileInfo = function (authResponse) {
      var info = $q.defer();

      facebookConnectPlugin.api('/me?fields=email,name&access_token=' + authResponse.accessToken, null,
          function (response) {
              info.resolve(response);
          },
          function (response) {
              info.reject(response);
          }
      );
      return info.promise;
  };

  var LoginSuccess = function(response){
      var authResponse = response.authResponse;

      GetProfileInfo(authResponse).then(function(user) {
          StorageService.setLoginUser({
              name: user.name,
              id: user.id,
              email: user.email,
              profile_url: "http://graph.facebook.com/" + authResponse.userID + "/picture?type=large"
          });
          myNavigator.pushPage('profile.html');
      }, function(error){
          console.log('Error retrieving user profile' + JSON.stringify(error));
      });

  };

  var LoginError = function(error){
      console.log('Login Error: ' + JSON.stringify(error));
      // When "User cancelled dialog" error appears
      if (error.errorCode === "4201"){
          CheckLoginStatus();
      }
  };

  $scope.Login = function(){
      facebookConnectPlugin.login(['email', 'public_profile'], LoginSuccess, LoginError);
  }


})
.controller('ProfileCtrl', function($scope, StorageService, $http, $q) {
  $scope.user = StorageService.getLoginUser();

  var LogoutFromFacebook = function(){
      facebookConnectPlugin.logout(
          function() {
              console.log('Successful logout!');
              myNavigator.pushPage("home.html");
          },
          function(error) {
              console.log('Error logging out: ' + JSON.stringify(error));
          }
      );
  }

  $scope.Logout = function(){
      ons.notification.confirm({
          message: "Are you sure you want to log out?",
          title: 'Facebook Demo',
          buttonLabels: ["Yes", "No"],
          callback: function(idx) {
          switch (idx) {
              case 0:
                  LogoutFromFacebook();
              case 1:
                  break;
              break;
          }
        }
      });
  }
});

Inside this file, there is a service, called StorageService, to store the login information of the user using the device’s Local Storage. There are also two controllers such as HomeCtrl and ProfileCtrl which are the controllers for home.html and profile.html pages, respectively.

HomeCtrl controller consists of several functions used within the home.html page. Once, the page is loaded, the CheckLoginStatus() function is triggered to check if there is any existing login information. If the login information is found, the myNavigator.pushPage() function is called to navigate to profile.html page showing the user’s Facebook profile as found in the login information. When the user clicks on Connect to Facebook button, the Login() function is triggered. In this function, the facebookConnectPlugin.login() function is called to show the native Facebook authentication dialog. If the login is successful, the login information will be stored in the device’s local storage via StorageService.setLoginUser() function and then the myNavigator.pushPage() function is called to navigate to profile.html page.

If you have logged in with a Facebook app on your device, the information of that account will be automatically grabbed and used in this app. If you want to login with a different account, please go to your Facebook app and change the account there.

However, if you do not have a Facebook app on your device or you have not logged in the existing Facebook app on your device, the following authentication screen will appear:

In the ProfileCtrl controller, there are 2 functions: Logout() and LogoutFromFacebook(). The Logout() function is called when the user clicks on the Logout icon on the top-right corner of the Profile page. Inside the Logout() function, a confirmation dialog is shown. If the user selects Yes, both LogoutFromFacebook() function StorageService service are called to log the user out and remove the login information from the device’s local storage, respectively.