Templated Helpers and SelectLists in the View Model don't mix: true?

It seems like there's a disconnect in the advised best practices when it comes to including the data source of a select list in a view model. For example, many best practices blog posts will recommend something along these lines:

ViewModel:

public class InvoiceViewModel 
{
     [UIHint("SelectInvoiceType")]
     public int idInvoiceType { get; set; }

     /* snip */

     /* I'll use this in the view to generate a SelectList */
     public List<invoicetype> InvoiceTypes { get; set; }
}

But then when we get to the editor template, the Model object will be just the int, with no knowledge of the containing view model:

SelectInvoiceType.cshtml

@model int
@{
  Layout = "~/Views/Shared/_EditorFormItem.cshtml";
  List<SelectListItem> selList = /* nothing to say here, really */;
}
@section DataContent {
   @Html.DropDownListFor(m => Model, selList, null)
}

So, unless I'm missing something, these two "best practices" -- templated view helpers and strong开发者_运维问答ly-typed list data in the view model -- just can't be used together. You have to resort to stuffing your list data into the ViewBag. Sound about right?

Sorry to sound incredulous, but I feel like I must be missing something.

---

You have to resort to stuffing your list data into the ViewBag. Sound about right?

No. To me stuffing things in ViewBag/ViewData doesn't sound right. You should not use int as a model type to an editor template that is supposed to generate a dropdownlist. A dropdownlist consists of two properties: a scalar type to bind the selected value to and a collection to be used to generate the different options in this ddl.

So a more correct way would be the following:

public class MyViewModel
{
    [UIHint("SelectInvoiceType")]
    public InvoiceTypesViewModel Invoice { get; set; }

    ... some other properties specific to the view
}

where InvoiceTypesViewModel is a view model and doesn't contain any reference to domain models such as invoicetype in the list in your example:

public class InvoiceTypesViewModel
{
     public int SelectedInvoiceType { get; set; }
     public SelectList InvoiceTypes { get; set; }
}

then in your main view:

@model MyViewModel
...
@Html.EditorFor(x => x.Invoice)

and the editor template:

@model InvoiceViewModel
@Html.DropDownListFor(m => m.SelectedInvoiceType, Model.InvoiceTypes)