System.NullReferenceException-NerdDinner Tutorial - asp.net-mvc-3

Question

I am doing a ASP.NET MVC tutorial. I created a Dinner Controller as well as a index view of Dinner Controller. But, I got an error on my Dinner Index View. The error appears on the for each loop in the following code. But the dinner index view is generated by default. I didnt change any thing.
The code of my Dinner Index View is
#model IEnumerable<NerdDinner.Models.Dinner>
#{
ViewBag.Title = "Index";
}
<h2>Index</h2>
<p>
#Html.ActionLink("Create New", "Create")
</p>
<table>
<tr>
<th>
Title
</th>
<th>
Latitude
</th>
<th>
Longitude
</th>
<th>
EventDate
</th>
<th>
ContactPhone
</th>
<th>
Address
</th>
<th>
Country
</th>
<th>
HostedBy
</th>
<th>
Description
</th>
<th></th>
</tr>
#foreach (var item in Model) {//Error appears here
<tr>
<td>
#Html.DisplayFor(modelItem => item.Title)
</td>
<td>
#Html.DisplayFor(modelItem => item.Latitude)
</td>
<td>
#Html.DisplayFor(modelItem => item.Longitude)
</td>
<td>
#Html.DisplayFor(modelItem => item.EventDate)
</td>
<td>
#Html.DisplayFor(modelItem => item.ContactPhone)
</td>
<td>
#Html.DisplayFor(modelItem => item.Address)
</td>
<td>
#Html.DisplayFor(modelItem => item.Country)
</td>
<td>
#Html.DisplayFor(modelItem => item.HostedBy)
</td>
<td>
#Html.DisplayFor(modelItem => item.Description)
</td>
<td>
#Html.ActionLink("Edit", "Edit", new { id=item.DinnerID }) |
#Html.ActionLink("Details", "Details", new { id=item.DinnerID }) |
#Html.ActionLink("Delete", "Delete", new { id=item.DinnerID })
</td>
</tr>
}
</table>
The code of my Dinner controller is
namespace NerdDinner.Controllers
{
public class DinnerController : Controller
{
IDinnerRepository _repository;
public DinnerController()
{
_repository = new sqlDinnerRepository();
}
public DinnerController(IDinnerRepository repository)
{
_repository = repository;
}
//
// GET: /Dinner/
public ActionResult Index()
{
if (Request.IsAjaxRequest())
{
var dinners = _repository.FindAllDinners().Where(x => x.EventDate >= DateTime.Now).ToList();
return Json(dinners);
}
else
{
return View();
}
}
//
// GET: /Dinner/Details/5
public ActionResult Details(int id)
{
var dinner = _repository.GetDinner(id);
return View(dinner);
}
//
// GET: /Dinner/Create
public ActionResult Create()
{
return View();
}
//
// POST: /Dinner/Create
[HttpPost]
public ActionResult Create(Dinner dinner)
{
try
{
// TODO: Add insert logic here
_repository.AddDinner(dinner);
_repository.Save();
return RedirectToAction("Index");
}
catch
{
return View(dinner);
}
}
//
// GET: /Dinner/Edit/5
public ActionResult Edit(int id)
{
var dinner = _repository.GetDinner(id);
return View(dinner);
}
//
// POST: /Dinner/Edit/5
[HttpPost]
public ActionResult Edit(int id, FormCollection collection)
{
var dinner = _repository.GetDinner(id);
try
{
// TODO: Add update logic here
UpdateModel(dinner, collection.ToValueProvider());
_repository.Save();
return RedirectToAction("Index");
}
catch
{
return View(dinner);
}
}
//
// POST: /Dinner/Delete/5
[HttpPost]
public ActionResult Delete(int id)
{
var dinner = _repository.GetDinner(id);
try
{
// TODO: Add delete logic here
_repository.DeleteDinner(dinner);
_repository.Save();
return RedirectToAction("Index");
}
catch
{
return View(dinner);
}
}
}
}
IDinnerRepository is an interface and sqlDinnerRepository implements it
The code of IDinnerRepository is
namespace NerdDinner.Models
{
public interface IDinnerRepository
{
//Query Methods
IQueryable<Dinner> FindAllDinners();
IQueryable<Dinner> FindUpcomingDinners();
Dinner GetDinner(int id);
//Insert/Delete
void AddDinner(Dinner dinner);
void DeleteDinner(Dinner dinner);
//Persistence
void Save();
}
}
The code of sqlDinnerRepository is
namespace NerdDinner.Models
{
public class sqlDinnerRepository: IDinnerRepository
{
public dbDataContext db;
public sqlDinnerRepository()
{
db = new dbDataContext();
}
public IQueryable<Dinner> FindAllDinners()
{
return db.Dinners;
}
public IQueryable<Dinner> FindUpcomingDinners()
{
return from dinner in db.Dinners
where dinner.EventDate > DateTime.Now
orderby dinner.EventDate
select dinner;
}
public Dinner GetDinner(int id)
{
return db.Dinners.SingleOrDefault(x => x.DinnerID == id);
}
public void AddDinner(Dinner dinner)
{
db.Dinners.InsertOnSubmit(dinner);
}
public void Save()
{
db.SubmitChanges();
}
public void DeleteDinner(Dinner dinner)
{
db.Dinners.DeleteOnSubmit(dinner);
}
}
}
I have updated my database as well as LINQ data model.

Answer 1

return View();
You didn't pass any model to the view.
Therefore, Model is null.

Answer 2

This action does not send a model to the view when you make a regular GET request.
public ActionResult Index()
{
if (Request.IsAjaxRequest())
{
var dinners = _repository.FindAllDinners().Where(x => x.EventDate >= DateTime.Now).ToList();
return Json(dinners);
}
else
{
return View();
}
}
I don't know why default project does this but you can fix the NRE like this:
public ActionResult Index()
{
var dinners = _repository.FindAllDinners().Where(x => x.EventDate >= DateTime.Now).ToList();
if (Request.IsAjaxRequest())
{
return Json(dinners);
}
else
{
return View(dinners);
}
}