Question

I’ve been fiddling about and trying multiple things, but I’m going wrong somewhere. I tried to make my first attempt using AutoMapper as simple as possible. I’m trying to create a new Brand and save it to the database, using a CreateBrandViewModel. Some of this might look a bit fruity, but I was trying to get it to work in the simplest way possible.

Domain:

public class Brand : EntityBase
{
    public virtual string Name { get; set; } //Not Nullable
    public virtual bool IsActive { get; set; } // Not Nullable
    public virtual Product DefaultProduct { get; set; } // Nullable
    public virtual IList<Product> Products { get; set; } // Nullable
}

ViewModel:

public class CreateBrandViewModel
{
    public string Name { get; set; }
    public bool IsActive { get; set; }
}

Controller

this is where I’ve been playing about the most for a while, so it looks a bit strange now. The commented out code hasn’t resolved my problem.

    [HttpPost]
    public ActionResult Create(CreateBrandViewModel createBrandViewModel)
    {
        if(ModelState.IsValid)
        {

            Mapper.CreateMap<Brand, CreateBrandViewModel>();
                //.ForMember(
                //    dest => dest.Name,
                //    opt => opt.MapFrom(src => src.Name)
                //)
                //.ForMember(
                //    dest => dest.IsActive,
                //    opt => opt.MapFrom(src => src.IsActive)
                //);

            Mapper.Map<Brand, CreateBrandViewModel>(createBrandViewModel)
            Session.SaveOrUpdate(createBrandViewModel);
            return RedirectToAction("Index");
        }

        else
        {
            return View(createBrandViewModel);
        }
    }

Just for the record, BrandController inherits from SessionController (Ayendes way), and transactions are managed through an ActionFilter. Though thats is a bit irrelevant I think. I’ve tried various different ways so I have different error messages – if you can take a look at whats happening and tell me how you might expect to use it that would be great.

For reference, my fluent nhibernate mapping for Brand:

public class BrandMap : ClassMap<Brand>
{
    public BrandMap()
    {
        Id(x => x.Id);

        Map(x => x.Name)
            .Not.Nullable()
            .Length(50);

        Map(x => x.IsActive)
            .Not.Nullable();

        References(x => x.DefaultProduct);

        HasMany(x => x.Products);

    }
}

Edit 1

I just tried the following code, but putting a breakpoint on Session.SaveOrUpdate(updatedModel) the fields are null and false, when they shouldn’t be:

            var brand = new Brand();
            var updatedBrand = Mapper.Map<Brand, CreateBrandViewModel>(brand, createBrandViewModel);
            Session.SaveOrUpdate(updatedBrand);
            return RedirectToAction("Index");
        }

Answer 1

You appear to be doing your mapping the wrong way around on your return trip from the post. The alternative syntax may help out here, try:

// setup the viewmodel -> domain model map 
// (this should ideally be done at initialisation time, rather than per request)
Mapper.CreateMap<CreateBrandViewModel, Brand>();
// create our new domain object
var domainModel = new Brand();
// map the domain type to the viewmodel
Mapper.Map(createBrandViewModel, domainModel);
// now saving the correct type to the db
Session.SaveOrUpdate(domainModel);

let me know if that cracks the egg… or just egg on yer face again 🙂