How to keep related entities on object when returned from ASP.NET MVC view

I am working on an ASP.NET MVC RC2 app using Entity Framework.

This is my Entity diagram.

In my repository I get the entity like this:

public Product GetProduct(int id)
{
    return (from c in _entities.ProductSet.Include("User")
           where c.Id == id
           select c).FirstOrDefault();
}

My view:

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<SampleApp.Models.Product>" %>

Edit product

<h2>Edit product</h2>

<%= Html.ValidationSummary("Edit was unsuccessful. Please correct the errors and try again.") %>

<% using (Html.BeginForm()) {%>

    <fieldset>
        <legend>Fields</legend>
        <p>
            <label for="Id">Id:</label>
            <%=  Model.Id %>
        </p>
        <p>
            <label for="Title">Title:</label>
            <%= Html.TextBox("Title", Model.Title) %>
            <%= Html.ValidationMessage("Title", "*") %>
        </p>
        <p>
            <label for="Body">Body:</label>
            <%= Html.TextBox("Body", Model.Body) %>
            <%= Html.ValidationMessage("Body", "*") %>
        </p>
        <p>
            <input type="submit" value="Save" />
        </p>
    </fieldset>

<% } %>

<div>
    <%=Html.ActionLink("Back to List", "Index") %>
</div>

Problem and my question is: When the "Product" entity is returned from the view on post, the linked entity "User" is null. Why is that and is there any way to get around this?

From stackoverflow

• Because the productToEdit is a new product object populated from the form fields and if you don't have fields for the user how would you populate the User entity

  For a "workaround", first get the product from the db, edit this with the edited fields in the productToEdit and save to db

  jesperlind : I thought this was the case of the object "being new" coming from the view. I don't need to change the user in my scenario. The user is only in the relation to track who created the product. Thanks for this info, I will work around it.

• You can also choose to use a custom ModelBinder that understands your model & persistence strategy to fully load the graph back into memory.

  jesperlind : Thanks that sounds promising, I'll look into that. I solved the above by problem attaching the original object in the Edit-function in the service. In this way it passes the same validation I got when I create a Product. (Product must have User)