R – Force NHibernate to issue an update

You shouldn't. NHibernate sessions are there to help you work in an ACID environment, which means that one transaction is not aware of any concurrent transactions. You should be using short sessions which do small sets of actions. You should not be holding sessions open for long periods of time. If you do need long periods of time for working with domain objects, then you should be detaching and then re-attaching the domain objects from and to different sessions.

Once you open a new session, any changes done to the database before the session was opened will be made available through NHibernate.

Here's how I do it.

I decided to use IPrincipal instead of IIdentity because it means I don't have to implement both IIdentity and IPrincipal.

1. Create the interface

   interface ICustomPrincipal : IPrincipal
   {
       int Id { get; set; }
       string FirstName { get; set; }
       string LastName { get; set; }
   }
   

2. CustomPrincipal

   public class CustomPrincipal : ICustomPrincipal
   {
       public IIdentity Identity { get; private set; }
       public bool IsInRole(string role) { return false; }
   
       public CustomPrincipal(string email)
       {
           this.Identity = new GenericIdentity(email);
       }
   
       public int Id { get; set; }
       public string FirstName { get; set; }
       public string LastName { get; set; }
   }
   

3. CustomPrincipalSerializeModel - for serializing custom information into userdata field in FormsAuthenticationTicket object.

   public class CustomPrincipalSerializeModel
   {
       public int Id { get; set; }
       public string FirstName { get; set; }
       public string LastName { get; set; }
   }
   

4. LogIn method - setting up a cookie with custom information

   if (Membership.ValidateUser(viewModel.Email, viewModel.Password))
   {
       var user = userRepository.Users.Where(u => u.Email == viewModel.Email).First();
   
       CustomPrincipalSerializeModel serializeModel = new CustomPrincipalSerializeModel();
       serializeModel.Id = user.Id;
       serializeModel.FirstName = user.FirstName;
       serializeModel.LastName = user.LastName;
   
       JavaScriptSerializer serializer = new JavaScriptSerializer();
   
       string userData = serializer.Serialize(serializeModel);
   
       FormsAuthenticationTicket authTicket = new FormsAuthenticationTicket(
                1,
                viewModel.Email,
                DateTime.Now,
                DateTime.Now.AddMinutes(15),
                false,
                userData);
   
       string encTicket = FormsAuthentication.Encrypt(authTicket);
       HttpCookie faCookie = new HttpCookie(FormsAuthentication.FormsCookieName, encTicket);
       Response.Cookies.Add(faCookie);
   
       return RedirectToAction("Index", "Home");
   }
   

5. Global.asax.cs - Reading cookie and replacing HttpContext.User object, this is done by overriding PostAuthenticateRequest

   protected void Application_PostAuthenticateRequest(Object sender, EventArgs e)
   {
       HttpCookie authCookie = Request.Cookies[FormsAuthentication.FormsCookieName];
   
       if (authCookie != null)
       {
           FormsAuthenticationTicket authTicket = FormsAuthentication.Decrypt(authCookie.Value);
   
           JavaScriptSerializer serializer = new JavaScriptSerializer();
   
           CustomPrincipalSerializeModel serializeModel = serializer.Deserialize<CustomPrincipalSerializeModel>(authTicket.UserData);
   
           CustomPrincipal newUser = new CustomPrincipal(authTicket.Name);
           newUser.Id = serializeModel.Id;
           newUser.FirstName = serializeModel.FirstName;
           newUser.LastName = serializeModel.LastName;
   
           HttpContext.Current.User = newUser;
       }
   }
   

6. Access in Razor views

   @((User as CustomPrincipal).Id)
   @((User as CustomPrincipal).FirstName)
   @((User as CustomPrincipal).LastName)
   

and in code:

    (User as CustomPrincipal).Id
    (User as CustomPrincipal).FirstName
    (User as CustomPrincipal).LastName

I think the code is self-explanatory. If it isn't, let me know.

Additionally to make the access even easier you can create a base controller and override the returned User object (HttpContext.User):

public class BaseController : Controller
{
    protected virtual new CustomPrincipal User
    {
        get { return HttpContext.User as CustomPrincipal; }
    }
}

and then, for each controller:

public class AccountController : BaseController
{
    // ...
}

which will allow you to access custom fields in code like this:

User.Id
User.FirstName
User.LastName

But this will not work inside views. For that you would need to create a custom WebViewPage implementation:

public abstract class BaseViewPage : WebViewPage
{
    public virtual new CustomPrincipal User
    {
        get { return base.User as CustomPrincipal; }
    }
}

public abstract class BaseViewPage<TModel> : WebViewPage<TModel>
{
    public virtual new CustomPrincipal User
    {
        get { return base.User as CustomPrincipal; }
    }
}

Make it a default page type in Views/web.config:

<pages pageBaseType="Your.Namespace.BaseViewPage">
  <namespaces>
    <add namespace="System.Web.Mvc" />
    <add namespace="System.Web.Mvc.Ajax" />
    <add namespace="System.Web.Mvc.Html" />
    <add namespace="System.Web.Routing" />
  </namespaces>
</pages>

and in views, you can access it like this:

@User.FirstName
@User.LastName