MVC 3 Post of Viewmodel with Completex IEnumerable - asp.net-mvc-3

Question

I have a complex class that is part of a property of a viewmodel. My viewmodel has a wine class property and a wine class has a ICollection property called CaseProductions. The CaseProduction class has several properties as well.
On the create GET event, the NewWineViewModel is instantiated, then it runs a GetCaseProductionDefaults with create a list of CaseProduction classes that have some default values, but are mostly empty.
Now, I originally used razor to do a foreach statement and just pop out my table the way I wanted it. But I've see around that doesn't work to bind this type of IEnumerable back to the viewmodel on POST. I've tried to use the below, but no dice.
EditorFor(m => m.Wine.CaseProductions)
I'm really looking for advise on what the best way to handle this is. Each wine will have a collection of caseproductions, and I want that to bind back to the wine within the viewmodel. Is their some way I can edit the ids of those elements in razor to make sure they bind? What's the best way to handle this one?
viewmodel:
public class NewWineViewModel
{
public Wine Wine { get; set; }
public VOAVIRequest VOAVIRequest { get; set; }
public bool IsRequest { get; set; }
public Dictionary<int, int> BottlesPerCase { get; set; }
public SelectList VarTypes { get; set; }
public SelectList Origins { get; set; }
public SelectList Apps { get; set; }
public SelectList Vintages { get; set; }
public SelectList Importers { get; set; }
}
case production class:
public class CaseProduction
{
public int CaseProductionID { get; set; }
public int WineID { get; set; }
public int CaseProductionSizeID { get; set; }
public int CaseCount { get; set; }
public int CountPerCase { get; set; }
public virtual CaseProductionSize CaseProductionSize { get; set; }
public virtual Wine Wine { get; set; }
}
getting default case productions:
public List<CaseProduction> GetCaseProductionDefaults(vfContext db)
{
//creates blank list of all formats
List<CaseProduction> cp = new List<CaseProduction>();
foreach (CaseProductionSize size in db.CaseProductionSizes)
{
int defaultBottlesPerCase = 1;
switch ((CaseProductionSizeEnum)size.CaseProductionSizeID)
{
case CaseProductionSizeEnum.s187ml:
defaultBottlesPerCase= 24;
break;
case CaseProductionSizeEnum.s375ml:
defaultBottlesPerCase = 12;
break;
case CaseProductionSizeEnum.s500ml:
defaultBottlesPerCase = 12;
break;
case CaseProductionSizeEnum.s750ml:
defaultBottlesPerCase = 12;
break;
default:
defaultBottlesPerCase = 1;
break;
}
cp.Add(new CaseProduction { CaseProductionSizeID = size.CaseProductionSizeID, CountPerCase = defaultBottlesPerCase, CaseProductionSize = size, WineID = this.Wine.WineID });
}
return cp;
}
my razor code for the case production table:
#foreach (vf2.Models.CaseProduction cp in Model.Wine.CaseProductions)
{
<tr>
<td>#cp.CaseProductionSize.Name
</td>
<td>#Html.Raw(#Html.TextBoxFor(m => m.Wine.CaseProductions.Where(c => c.CaseProductionSizeID == cp.CaseProductionSizeID).First().CaseCount, new { #class = "caseCount", id = "txt" + cp.CaseProductionSize.Name }).ToString().Replace("CaseCount","txt" + cp.CaseProductionSize.Name))
</td>
<td>
#Html.DropDownListFor(m => m.Wine.CaseProductions.Where(c => c.CaseProductionSizeID == cp.CaseProductionSizeID).First().CountPerCase, new SelectList(Model.BottlesPerCase, "Key", "Value", cp.CountPerCase), new { #class = "countPerCase", id = "ddl" + cp.CaseProductionSize.Name, name = "ddl" + cp.CaseProductionSize.Name})
</td>
<td class="totalBottleCalc">
</td>
</tr>
}
instantiation of my caseproduction collection:
public ActionResult Create(int ID = 0, int VintUpID = 0)
{
NewWineViewModel nw = new NewWineViewModel();
nw.Wine.CaseProductions = nw.GetCaseProductionDefaults(db);
nw.BottlesPerCase = nw.GetBottlesPerCase(db);

Answer 1

I believe the model binder isn't picking up on your CaseProduction objects because they don't look like a CaseProduction objects.
You have renamed CaseCount, your CaseProductionSize has no Id (nor does you CaseProduction, and it's missing several properties. In your loop you have to include all properties, and keep the names consistent with the names of your POCOs. Otherwise the model binder won't know what they are. You can put all the properties in hidden fields if you want.

Answer 2

You must instantiate your nested Lists and complex models in your parent models constructor. The default model binder will not instantiate child classes.
If you do that, then you can use the EditorFor(m => m.Wine.CaseProductions) should work, and you don't need the complex view code you are using.
If you want to customize how the CaseProduction is rendered, then you can create a CaseProduction.cshtml file in ~/Shared/EditorTemplates and it will use this definition to render each item in the collection (it will automatically iterate over the collection for you).
Also, you shouldn't do linq queries in your view. Your problem there is that it looks like you're passing your data entity directly to the view. This is bad design. You need to instead create a ViewModel that contains only the information needed to render the view. Then, you filter your data before you assign it to the View model.