Question

I’m having a bit of trouble figuring out how to make this repository pattern work.

In a nutshell, my solution looks something like this…

        ASP.Net MVC
             ^
             |
       Business Logic
             ^
             |
       Data Access 
(Repositories and Unit of Work)
             ^
             |
  Entity Framework Models

I have a Users table with a reference to a Roles table.

In my MVC app, I call the BLL with a GetAllUsers. The code in the BLL looks like this:

public List<User> GetAllUsers()
{
    using (UnitOfWork uow = new UnitOfWork())
    {
        UserRepository userRepository = new UserRepository(uow);
        return userRepository.GetAll().ToList();
    }
}

The UserRepository derives from GenericRepository, which has a GetAll()

public class GenericRepository<T> : IGenericRepository<T> where T : class
{
    private IUnitOfWork _uow = null;

    public GenericRepository(IUnitOfWork uow)
    {
        _uow = uow;
    }

    public virtual IQueryable<T> GetAll()
    {
        return _uow.Set<T>().AsQueryable();
    }
}

It returns a list of users to my MVC app, but when I try and access the Role reference, it hasn’t loaded yet due to lazy loading.

public ActionResult Index()
{
    BusinessLogic.Account blAcct = new BusinessLogic.Account();
    List<User> users = blAcct.GetAllUsers();

    string firstName = users.FirstName;  // Works fine
    string role = users.Roles.RoleName;  // Fails because the context is closed.

    return View();
}

I’ve tried to put an .Include(Roles) on the GetAllUsers, but .Include isn’t available on IQueryable.

Theoretically speaking, am I right in thinking that the MVC app shouldn’t need to know anything about the context or the data access?
And second, how should I be including this Roles reference in my graph before it leaves the BLL?

Answer 1

You are right in thinking your MVC application, given your current application architecture, should not be concerned with the DataContext and data retrieval.

A solution may be to add another Repository method that eagerly loads your Roles:

public IList<Users> GetAllUsersWithRoles()

Then selectively use the method that is appropriate, given the context.