ASP.MVC 2 Model Data Persistance

Question

I'm and MVC1 programmer, new to the MVC2.

The data will not persist to the database in an edit scenario. Create works fine.

Controller:

    //
    // POST: /Attendee/Edit/5

    [Authorize(Roles = "Admin")]
    [AcceptVerbs(HttpVerbs.Post)]
    public ActionResult Edit(Attendee attendee)
    {

        if (ModelState.IsValid)
        {
            UpdateModel(attendee, "Attendee");
            repository.Save();

            return RedirectToAction("Details", attendee);
        }
        else
        {
            return View(attendee);
        }
    }

Model:

[MetadataType(typeof(Attendee_Validation))]
public partial class Attendee
{
}

public class Attendee_Validation
{

    [HiddenInput(DisplayValue = false)]
    public int attendee_id { get; set; }

    [HiddenInput(DisplayValue = false)]
    public int attendee_pin { get; set; }

    [Required(ErrorMessage = "* required")]
    [StringLength(50, ErrorMessage = "* Must be under 50 characters")]
    public string attendee_fname { get; set; }

    [StringLength(50, ErrorMessage = "* Must be under 50 characters")]
    public string attendee_mname { get; set; }
}

I tried to add [Bind(Exclude="attendee_id")] above the Class declaration, but then the value of the attendee_id attribute is set to '0'.

View (Strongly-Typed):

<% using (Html.BeginForm()) {%>
    ...
    <%=Html.Hidden("attendee_id", Model.attendee_id) %>
    ...
    <%=Html.SubmitButton("btnSubmit", "Save") %>
<% } %>

Basically, the repository.Save(); function seems to do nothing. I imagine it has something to do with a primary key constraint violation. But I'm not getting any errors from SQL Server. The application appears to runs fine, but the data is never persisted to the Database.

Answer 1

I think you should first get an instance of the attendee class from repository before you call Save function.

var attendeeToEdit=repository.GetAttendee(attendee.ID);
UpdateModel(attendeeToEdit);

I'm guessing something like that may work. Try it and see if it works.

Answer 2

Got It! Here's the solution:

[AcceptVerbs(HttpVerbs.Post)]
public ActionResult Edit(int id, FormCollection form)
{
    Attendee attendee = repository.GetAttendee(id);

    try
    {
        UpdateModel(attendee, form);
        repository.Save();

        return RedirectToAction("Details", attendee);
    }
    catch
    {
        return View(attendee);
    }
}

The UpdateModel() ValueProvider was the problem.