I use View Models to hand to my MVC views, nice and slim with little if any methods on them and I use a think ORM model that has all my business logic and is generated by my ORM (BLToolkit).

So the problem is I wanted to take the View Model and update the ORM model with the modified values from the post, kind of a reverse AutoMapper (or BLToolkit.Mapper).

So a ORM class like this;

    public class Contact
    {
         public int Id { get; set; }
         public string Firstname { get; set; }
         public string Lastname { get; set; }
         // Loads of other properties
    }

And a View Model like this (note the type and name should be “EXACTLY” the same;

    public class ContactModel
    {
         public int Id { get; set; }
         public string Firstname { get; set; }
         public string Lastname { get; set; }
    }

Then with this generic Extension method;

        public static void MergeWith(this T1 primary, T2 secondary)
        {
            foreach (var pi in typeof(T2).GetProperties())
            {
                var tpi = typeof(T1).GetProperties().Where(x => x.Name == pi.Name).FirstOrDefault();
                if (tpi == null)
                {
                    continue;
                }
                var priValue = tpi.GetGetMethod().Invoke(primary, null);
                var secValue = pi.GetGetMethod().Invoke(secondary, null);
                if (priValue == null || !priValue.Equals(secValue))
                {
                    tpi.GetSetMethod().Invoke(primary, new object[] { secValue });
                }
            }
        }

So you make the magic in the Controller (for example) like this;

[Authorize]
[HttpPost]
[ValidateAntiForgeryToken]
[ValidateInput(false)]
public ActionResult EditContact(ContactModel model)
    Contact c = Repo.Get<Contact,long>(model.Id);
    c.MergeWith<Contact,ContactModel>(model);
    Repo.Update<Contact>(c);
}

Yea its cheesy, but it works for me

Enjoy!