Does the Facebook .NET client SDK support universal apps / apps generated via AppStudio?

Question

I created a universal app via Microsoft's AppStudio. I tried adding Facebook authentication to the app by following the 'Scrumptious tutorial' (http://facebooksdk.net/docs/phone/tutorial/).

When I run the app on my phone, I can never get to the facebook login page, because the following line: await App.FacebookSessionClient.LoginAsync("user_about_me,read_stream");

always results in the following exception:

System.NotImplementedException: Not implemented
at Windows.Security.Authentication.Web.WebAuthenticationBroker.AuthenticateAsync(WebAuthenticationOptions options, Uri requestUri, Uri callbackUri) at Facebook.Client.FacebookSessionClient.d__24.MoveNext()

The source of the exception is this call in the FacebookSessionClient.cs (facebook-client package): var result = await WebAuthenticationBroker.AuthenticateAsync(options, startUri, endUri);

It seems that this function is not implemented for the phone. I am still wondering how it is possible that the turial, which refers to the exact same code would work.

Answer 1

It's not implemented for 8.1 yet. If you want to use Facebook authentication in 8.1 you can use the following approach:

In your App class:

private const string RedirectUrl = "https://www.facebook.com/connect/login_success.html";
private static readonly IReadOnlyCollection<string> Permissions = new[] { "email", "offline_access" };

protected override void OnActivated(IActivatedEventArgs args)
{
    base.OnActivated(args);
    var continuationActivatedEventArgs = args as IContinuationActivatedEventArgs;
    if (continuationActivatedEventArgs == null)
        return;
    var webAuthenticationResult = ((WebAuthenticationBrokerContinuationEventArgs)continuationActivatedEventArgs).WebAuthenticationResult;
    if (webAuthenticationResult.ResponseStatus == WebAuthenticationStatus.Success)
    {
        var facebookClient = new FacebookClient();
        var result = facebookClient.ParseOAuthCallbackUrl(new Uri(webAuthenticationResult.ResponseData));
        if (!result.IsSuccess)
        {
            // Process unsuccessful authentication
        }
        else
        {
            // Process successful authentication
            var accessToken = result.AccessToken;
        }
    }
}

// Authentication method, this method should be invoked when you click Facebook authentication button
public void AuthenticateAndContinue()
{
    var loginUrl = GetLoginUrl();
    WebAuthenticationBroker.AuthenticateAndContinue(loginUrl, new Uri(RedirectUrl));
}

private Uri GetLoginUrl()
{
    var parameters = new Dictionary<string, object>();
    parameters["client_id"] = "YourFacebookApplicationId";
    parameters["redirect_uri"] = RedirectUrl;
    parameters["response_type"] = "token";
    parameters["display"] = "touch";
    parameters["mobile"] = true;
    parameters["scope"] = String.Join(",", Permissions);

    var facebookClient = new FacebookClient();

    return facebookClient.GetLoginUrl(parameters);
}

I put everything in one place just for example purposes, it's better to separate fb authentication logic. You can find this approach here MSDN Windows Phone 8.1 Web Authentication samples