Using AutoMapper in the Edit action method in an MVC3 application

Question

Here is my controller code, which works 100% as I need it to. However the POST method isn't using the AutoMapper and that is not OK. How can I use AutoMapper in this action method?

I'm using Entity Framework 4 with the Repository Pattern to access data.

public ActionResult Edit(int id)
{
    Product product = _productRepository.FindProduct(id);
    var model = Mapper.Map<Product, ProductModel>(product);
    return View(model);
}

[HttpPost]
public ActionResult Edit(ProductModel model)
{
    if (ModelState.IsValid)
    {
        Product product = _productRepository.FindProduct(model.ProductId);

        product.Name = model.Name;
        product.Description = model.Description;
        product.UnitPrice = model.UnitPrice;

        _productRepository.SaveChanges();

        return RedirectToAction("Index");
    }

    return View(model);
}

If I use AutoMapper, the entity framework reference is lost and the data doesn't persist to the database.

[HttpPost]
public ActionResult Edit(ProductModel model)
{
    if (ModelState.IsValid)
    {
        Product product = _productRepository.FindProduct(model.ProductId);
        product = Mapper.Map<ProductModel, Product>(model);

        _productRepository.SaveChanges();

        return RedirectToAction("Index");
    }

    return View(model);
}

I'm guessing this is caused the Mapper.Map function returning a brand new Product object and because of that, no references to the entity framework graph is being kept. What alternatives do you suggest?

It's not clear what the problem you are experiencing is. You say that your POST method is not using Automapper, but I don't see any Automapper code in your `[HttpPost]` method. — Robert Harvey, Jan 13 '12 at 00:40
Not sure he means automapper Robert, think he means "modelbinder" but I'm not 100% sure — Keith Nicholas, Jan 13 '12 at 00:44
I edited in more details that should make the problem clearer. I don't mean ModelBinder, I mean the actual lib called AutoMapper. — Only Bolivian Here, Jan 13 '12 at 00:44
oh, you want the map to map to an EXISTING object... what you are doing is turning a ProductModel into a new Product object. — Keith Nicholas, Jan 13 '12 at 00:47
@KeithNicholas: Yep, I know that's the problem. Can you suggest alternatives? I don't *want* to create a new Product object, but the Mapper.Map() method does this. Unless I am missing something. — Only Bolivian Here, Jan 13 '12 at 00:49

score 15 · Accepted Answer · answered Jan 13 '12 at 00:49

15

I think you just do

 Product product = _productRepository.FindProduct(model.ProductId);
 Mapper.Map(model, product);
 _productRepository.SaveChanges();

you may also want to check that you have a non null product first, and also that user is allowed to change that product....

answered Jan 13 '12 at 00:49

Keith Nicholas

43,549
15
93
156

Its correct , Actually we have to **create Map for Get and Post of Edit Method** , for Get Its: Domain Model To ViewModel Mappings and for Post Its: ViewModel To Domain Model Mappings , check [this](http://stackoverflow.com/a/26908339/2218697), hope helps someone. – Shaiju T Mar 28 '16 at 16:08

Using AutoMapper in the Edit action method in an MVC3 application

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