Question

My MVC application allows a subset of users to insert/edit records in a table, and since I’m using Windows authentication I get their samaccountnames “for free” and can insert these in a “Last Updated By” field in the mentioned records.

One of the most important (and frequently used) views in my application will display lists of 50-100 records per page, but I don’t want to display their samaccountnames. I want their more user-friendly display names that I want to get from Active Directory.

I’ve seen several posts here suggesting linking AD to SQL, but that requires installing components on the SQL server which I’d rather not do. Instead, I was thinking of creating the following interface and derived class:

public interface IUserInformationStore
{
  UserInformation FindBySamAccountName(string samAccountName)
}

public class ActiveDirectoryStore
{
  HashSet<UserInformation> _cache;

  public UserInformation FindBySamAccountName(string samAccountName)
  {
    // Look for samaccountname in _cache and if not found
    // retrieve information from AD with DirectorySearcher.
    // Store information in _cache and return correct user.
}

My problem now is how to access this information. I was thinking of using Ninject’s ToSingleton, but I suspect that might be “Singleton Per Worker process”. So maybe the Cache would be a better place for it. But what would be the best way of accessing the object? Static class with static property that checks if it’s in the Cache already, initializes it otherwise, and returns the object?

Or is there a completely better way of solving this problem?

Answer 1

I tried 2 solutions eventually:

1

kernel.Bind<IUserRepository>().To<ActiveDirectoryUserRepository>().InSingletonScope().WithConstructorArgument("rootPath", "LDAP://dc=tessdata,dc=no");

public static MvcHtmlString GetDisplayNameSingleton(this HtmlHelper htmlHelper, string samAccountName)
{
  var userRepository = DependencyResolver.Current.GetService<IUserRepository>();
  return new MvcHtmlString(userRepository != null ? userRepository.FindByUsername(samAccountName).DisplayName : "Ukjent");
}

2

kernel.Bind<IUserRepository>().To<ActiveDirectoryUserRepository>().WithConstructorArgument("rootPath", "LDAP://dc=tessdata,dc=no");

public static MvcHtmlString GetDisplayName(this HtmlHelper htmlHelper, string samAccountName)
{
  if (HttpRuntime.Cache["UserRepository"] == null)
  {
    var newUserRepository = DependencyResolver.Current.GetService<IUserRepository>();
    HttpRuntime.Cache.Add("UserRepository", newUserRepository, null, DateTime.MaxValue,
                                  TimeSpan.FromMinutes(20), CacheItemPriority.Default, null);
  }
  var userRepository = HttpRuntime.Cache["UserRepository"] as IUserRepository;
  return new MvcHtmlString(userRepository != null ? userRepository.FindByUsername(samAccountName).DisplayName : "Ukjent");
}

The second method was noticeably faster, especially after the first call when the repository was cached. You get better control over caching too. The first method will stay in memory until the application is restarted.

I’m not sure about best practice in either case though.