Question

I am building a ASP.NET MVC App that will allow a user to connect to one of several databases (with the same schema) depending upon their selection. The user will select a database prior to login and then be authenticated against that database.

I have added added several role providers to web.config, each with a different connection string corresponding to each of the available databases.

I understand that I can access the role providers with the Roles.providers collection but I don’t understand how I can choose which role provider is being user by the [Authorize] attribute in my controllers

My Controllers look something like this:

namespace MyApp.Controllers
{
    [Authorize(Roles = "admin")]
    public class AdminController : Controller
    {

I assume that this will check the users role against the default role provider.
How can I select at run time which role provider will be used for the [Authorize] attribute?

Answer 1

As far as I know, there’s no way to do what you’re suggesting. Attributes are static metadata that can’t be changed at run-time. However, even though it’s less convenient, you can accomplish what you want by redirecting if the user doesn’t have the appropriate role:

[Authorize]
public class AdminController : Controller {

  public ActionResult ActionRequiringRoleFoo() {
    if( !User.IsInRole( "foo" ) ) return RedirectToAction( "InsufficientPrivileges" );
    return View();
  }

If you want to have this behavior for all actions in your controller, you can override the OnActionExecuting method:

protected override void OnActionExecuting( ActionExecutingContext filterContext ) {
  base.OnActionExecuting( filterContext );
  if( filterContext.ActionDescriptor.ActionName != "InsufficientPrivileges" && 
    !User.IsInRole( "anon" ) ) filterContext.Result = new RedirectResult( "InsufficientPrivileges" );
}

I hope that helps.