Is it correct to inject a Facebook SDK wrapper using InSingletonScope with Ninject?

Question

I have written a wrapper around the C# Facebook SDK usign the following code:

public interface IFacebookService
{
    Uri GetLoginUri(string returnUrl);

    FacebookResult OAuth(string url, string code);

    void Post(string message, string accessToken);
}

The implementation looks like:

public class FacebookService : IFacebookService
{
    public Uri GetLoginUri(string returnUrl)
    {
        var oAuthClient = new FacebookOAuthClient(FacebookApplication.Current);

        // code removed for simplicity

        return uri;
    }

    public FacebookResult OAuth(string url, string code)
    {
        FacebookOAuthResult oauthResult;

        if (FacebookOAuthResult.TryParse(url, out oauthResult))
        {
            // code removed for simplicity
        }

        return result;
    }

    public void Post(string message, string accessToken)
    {
        var client = new FacebookClient(accessToken);

        // code removed for simplicity
    }
}

I use Ninject to inject this where needed to perform login using oauth and posting to the users Facebook wall.

I currently have this configured using:

kernel.Bind<IFacebookService>().To<FacebookService>().InSingletonScope();

Is it correct to use InSingletonScope? Since this is a third party library I am not sure if this is the right approach since all threads will share the instance.

Answer 1

I have no knowledge about the Facebook SDK. But as a general rule if the implementation is stateless then singleton is the correct scope. I assume this is the case with your implementation.