Authenticate Facebook via Windows Azure Mobile Services

 

Let’s first understand what does the word authentication means before we go to the technical concept of Facebook authentication.

 

What is authentication?

 

It’s a method where the user tries to connect to a certain domain or application so the user needs access to this domain/application here comes the role of authentication. Simply it’s a way to authorize users through a certain domain or application.

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Identity Providers

Facebook is an Identity Provider which a user can login through it to be authorized to access an Application and there is a variety of Identity providers like (Microsoft Account, Yahoo ID, Google ID, Facebook and Twitter).

Authentication

To use authentication with windows azure mobile services first you need to have a working Windows Azure Account then go to the portal (http://manage.windowsazure.com) in order to register the application for authentication and to configure the mobile services.

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After Logging into the Portal go to the Mobile Services tab and then choose your own mobile service that you’ve created before then click on the Identity

Now a page that has all of the supported identities will appear so that when you pick an Identity Provider for user authentication you must fill in its required fields. 

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To add the Facebook settings you must first register your Facebook application from the Facebook Developers site

Go to https://developers.facebook.com/   and if you didn’t register before press on Register Now then the Policy will appear to you read it then accept it and click done.

Now go to apps and press on create new app in order to create the Facebook app that you’ll use to authenticate the users

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Write the name of the Application and then press Continue.

Then you’ll be provided the APP ID and the APP Secret Key Copy them and then go back to the mobile service identity page and paste them in the Facebook settings.

Now go to the Data Tab and press on the created Table (ToDoItem) and click on permissions then choose Only Authenticated Users in all the permissions and now your app allows only authenticated users. Now to test your mobile service go to the previously created windows 8 app and add the following authentication code

Go to the MainPage.xaml.cs

Add this to the using statements 

using Windows.UI.Popups;

 

then add the following code to the MainPage Class

private MobileServiceUser user;
private async System.Threading.Tasks.Task Authenticate()
{
    while (user == null)
    {
        string message;
        try
        {
            user = await App.MobileService
                .LoginAsync(MobileServiceAuthenticationProvider.Facebook);
            message = 
                string.Format("You are now logged in - {0}", user.UserId);
        }
        catch (InvalidOperationException)
        {
            message = "You must log in. Login Required";
        }
 
 
    var dialog = new MessageDialog(message);
    dialog.Commands.Add(new UICommand("OK"));
    await dialog.ShowAsync();
}
 
 
}

 

And at the end replace the OnNavigatedTo method that implements the new Authenticate Method 

protected override async void OnNavigatedTo(NavigationEventArgs e)
{
    await Authenticate();
    RefreshTodoItems();
}

Now when running the Application it will first ask the user to sign in using Facebook then the user will be authorized to use the application. You can as well use the same mobile service with any other app for example Windows Phone or Android.

Create Your First Windows Azure Mobile Services

Azure SDK

 

As previously blogged about the features of a windows azure mobile service acting as a backend for the mobile application and what does azure offer developers first of all before creating the first mobile service you need to have Windows Azure SDK if you are going to link your application to the created mobile service which you can find here http://www.windowsazure.com/en-us/downloads/

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Where you can find the SDK for the target platform you are using to develop your application

 

Azure Account

 

Now it’s time to create your first Azure Mobile Service but in order to do so you must have a Windows Azure working account if you don’t have one you can register for a 90 days trial from http://www.windowsazure.com/en-us/pricing/free-trial/

Note: Internet Card or credit card that supports internet transactions is needed for authentication

 

Create your first mobile service

 

First of all you must go to the windows azure account portal from https://manage.windowsazure.com/ and sign in with your Microsoft account than you registered with for windows azure account

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Then after going to the portal the previous screen appears with all of the services you’ve created choose new and select mobile service

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After selecting create the following windows will appear for you to enter the URL for your mobile service and choose if you want to create a new Database and its region

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Then press next to take you to the next page which you’ll specify the DB settings and then press finish to create your mobile serviceImage

 

 

Once you’ve done these steps you’ve successfully created your first mobile service then what you can do next is to either link it to an existing application or create a new application via the mobile service which will create for you a simple ToDo list application for the target platform that you choose and create a todo table for your application to store the items the user enters via the mobile service.

 

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Windows Azure Mobile Services

Windows Azure Mobile Service

 

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As the whole point of cloud computing as a theory is to migrate the processing power away from the device as when for example when doing a task that takes a lot of processing like searching in a lot of data or processing a large image where this task will take a lot of time on the device but if the processing is done outside the device and the result was returned then that would be using the processing power as a service and will be a well use of the cloud computing and that’s what’s azure mobile services is all about.

Windows Azure mobile service is simply a service that runs on the mobile device and then a request is sent to the cloud (Windows Azure) with the data that needs to be processed or the task that needs to be executed and then the processing process happens on the cloud and the mobile service waits for the result until the processing process is done and the result is sent back to the mobile device.

Mobile Services also are used to store data in a windows azure SQL database which was formerly known as (SQL Azure), Azure Tables or BLOBs.

 

Reaching every platform

 

Windows Azure Mobile Services supports a lot of mobile platforms that are commonly used now a days like Android, IOS, Windows Phone and Windows 8 so using windows azure SDK you can reach every 1 of these platforms via the RESTFUL API and also it connects multiple client apps to the same mobile service as a backend.

Mobile Services Features

 

Windows Azure Mobile services has lots of features to support developers that depend on azure as a backend for their applications, the most popular features are push notifications and authentication.

Push Notifications

 

Notification is a way of delivering a message to the user of a certain system by using software and maybe hardware features to notify him/her about a new update in the system for example when received a new e-mail a notification appears on the screen and plays a sound so that the user would be alert to the new mail that have been received.

Most of the new social networks and e-mail clients now a days use the notifications system as they want their users to be updated with the new updates they have like Facebook, Twitter, Google plus, Windows Live, …etc.

Windows Azure mobile service has built a push notification hub for the developers to make the mobile application users be familiar with the latest updates and notify them with the most important data/updates so it’s easily implemented in the Windows Store, Windows Phone, Android and IOS applications. 

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Authentication with well-known Service providers

 

A lot people that want to access their services on the cloud must go through an authentication process where each user trying to access the services on the cloud must be authorized with an access specially that users accessing these services are from different identity providers.

That’s why Windows Azure made authentication to well-known identity providers like Facebook, Twitter, and Microsoft Account more easily through mobile services just by registering on the wanted identity provider developer website and asking for a token for the application and adding it to the mobile service the user can then be authenticated through the mobile service.