Question

I have a model object called Problem:

[Table(Name = "Problems")]
public class Problem
{
    [HiddenInput(DisplayValue = false)]
    [Column(IsPrimaryKey = true, IsDbGenerated = true, AutoSync = AutoSync.OnInsert)]
    public int ProblemId { get; set; }

    [Display(ResourceType = typeof(Resources.Resources), Name = "TablePersonStudentName")]
    [Column] public int StudentId { get; set; }

    [Display(ResourceType = typeof(Resources.Resources), Name = "TableCommunicationTypesName")]
    [Column] public int CommunicationTypeId { get; set; }

    [Display(ResourceType = typeof(Resources.Resources), Name = "TableProblemTypeName")]
    [Column] public int ProblemTypeId { get; set; }

    [Display(ResourceType = typeof(Resources.Resources), Name = "TableMitigatingCircumstanceLevelName")]
    [Column] public int MitigatingCircumstanceLevelId { get; set; }

    [Display(ResourceType = typeof(Resources.Resources), Name = "TableProblemDate")]
    [Column] public DateTime? DateTime { get; set; }

    [Display(ResourceType = typeof(Resources.Resources), Name = "TableProblemOutline")]
    [Column] public string Outline { get; set; }

    [Display(ResourceType = typeof(Resources.Resources), Name = "TableProblemFile")]
    [Column] public byte[] MitigatingCircumstanceFile { get; set; }

    [Display(ResourceType = typeof(Resources.Resources), Name = "TableProblemAbsentFrom")]
    [Column] public DateTime? AbsentFrom { get; set; }

    [Display(ResourceType = typeof(Resources.Resources), Name = "TableProblemAbsentUntil")]
    [Column] public DateTime? AbsentUntil { get; set; }

    [Display(ResourceType = typeof(Resources.Resources), Name = "TableProblemRequestedFollowUp")]
    [Column] public DateTime? RequestedFollowUp { get; set; }

    public CommunicationType CommunicationType { get; set; }

    public MitigatingCircumstanceLevel MitigatingCircumstanceLevel { get; set; }

    public ProblemType ProblemCategory { get; set; }

    public ICollection<ProblemCommunication> ProblemCommunications { get; set; }

    public ICollection<AssessmentExtension> AssessmentExtensions { get; set; }

    public ICollection<User> Users { get; set; }

}

As this model contains lots of objects from other database tables I am using dropdownlists in my view by using a viewModel:

public class ProblemViewModel
{
    public Problem Problem { get; set; }
    public SelectList Students { get; set; }
    public SelectList CommunicationType { get; set; }
    public SelectList MitigatingCircumstanceLevel { get; set; }
    public SelectList ProblemType { get; set; }
    public MultiSelectList ProblemUsers { get; set; }

    public ProblemViewModel(Problem problem, ISqlStudentRepository sqlStudentRepository, 
        ISqlCommunicationTypeRepository sqlCommunicationTypeRepository, ISqlMitigatingCircumstanceLevelRepository sqlMitigatingCircumstanceRepository,
        ISqlProblemTypeRepository sqlProblemTypeRepository, ISqlUserRepository sqlUserRepository,
        string username)
    {
        this.Problem = problem;
        this.Students = new SelectList(sqlStudentRepository.Students.ToList(), "StudentId", "FirstName");
        this.CommunicationType = new SelectList(sqlCommunicationTypeRepository.CommunicationTypes.ToList(), "CommunicationTypeId", "Name");
        this.MitigatingCircumstanceLevel = new SelectList(sqlMitigatingCircumstanceRepository.MitigatingCircumstanceLevels.ToList(), "MitigatingCircumstanceLevelId", "Name");
        this.ProblemType = new SelectList(sqlProblemTypeRepository.ProblemTypes.ToList(), "ProblemTypeId", "TypeName");
        this.ProblemUsers = new MultiSelectList(sqlUserRepository.Users.Where(s => s.UserName != username).ToList(), "UserId", "UserName");
    }
}

This is generate upon navigation to the Problem/Create controller method:

public ViewResult Create()
    {
        string username = User.Identity.Name;

        return View("Edit", new ProblemViewModel(new Problem(), sqlStudentRepository, 
            sqlCommunicationTypeRepository, sqlMitigatingCircumstanceRepository,
            sqlProblemTypeRepository, sqlUserRepository, username));
    }

Here is the ascx view:

<%@ Control Language="C#" Inherits="System.Web.Mvc.ViewUserControl<BournemouthUniversity.WebUI.Models.ProblemViewModel>" %>

        <div class="editor-field">
            <%: Html.HiddenFor(model => model.Problem.ProblemId)%>
            <%: Html.ValidationMessageFor(model => model.Problem.ProblemId)%>
        </div>

        <div class="editor-label">
            <%: Html.LabelFor(model => model.Problem.StudentId) %>
        </div>
        <div class="editor-field">
            <%: Html.DropDownListFor(model => model.Problem.StudentId, Model.Students)%>
            <%: Html.ValidationMessageFor(model => model.Problem.StudentId)%>
        </div>

        <div class="editor-label">
            <%: Html.LabelFor(model => model.Problem.CommunicationTypeId)%>
        </div>
        <div class="editor-field">
            <%: Html.DropDownListFor(model => model.Problem.CommunicationTypeId, Model.CommunicationType)%>
            <%: Html.ValidationMessageFor(model => model.Problem.CommunicationTypeId)%>
        </div>

        <div class="editor-label">
            <%: Html.LabelFor(model => model.Problem.ProblemTypeId)%>
        </div>
        <div class="editor-field">
            <%: Html.DropDownListFor(model => model.Problem.ProblemTypeId, Model.ProblemType)%>
            <%: Html.ValidationMessageFor(model => model.Problem.ProblemTypeId)%>
        </div>

        <div class="editor-label">
            <%: Html.LabelFor(model => model.Problem.MitigatingCircumstanceLevelId)%>
        </div>
        <div class="editor-field">
            <%: Html.DropDownListFor(model => model.Problem.MitigatingCircumstanceLevelId, Model.MitigatingCircumstanceLevel)%>
            <%: Html.ValidationMessageFor(model => model.Problem.MitigatingCircumstanceLevelId)%>
        </div>

        <div class="editor-label">
            <%: Html.LabelFor(model => model.Problem.DateTime)%>
        </div>
        <div class="editor-field">
            <%: Html.TextBoxFor(model => model.Problem.DateTime, new { @class = "datePicker" })%>
            <%: Html.ValidationMessageFor(model => model.Problem.DateTime)%>
        </div>

        <div class="editor-label">
            <%: Html.LabelFor(model => model.Problem.Outline)%>
        </div>
        <div class="editor-field">
            <%: Html.TextAreaFor(model => model.Problem.Outline, 6, 70, new { maxlength = 255 })%>
            <%: Html.ValidationMessageFor(model => model.Problem.Outline)%>
        </div>

        <div class="editor-label">
            <%: Html.LabelFor(model => model.Problem.AbsentFrom)%>
        </div>
        <div class="editor-field">
            <%: Html.TextBoxFor(model => model.Problem.AbsentFrom, new { @class = "datePicker" })%>
            <%: Html.ValidationMessageFor(model => model.Problem.AbsentFrom)%>
        </div>

        <div class="editor-label">
            <%: Html.LabelFor(model => model.Problem.AbsentUntil)%>
        </div>
        <div class="editor-field">
            <%: Html.TextBoxFor(model => model.Problem.AbsentUntil, new { @class = "datePicker" })%>
            <%: Html.ValidationMessageFor(model => model.Problem.AbsentUntil)%>
        </div>

        <div class="editor-label">
            <%: Html.LabelFor(model => model.Problem.RequestedFollowUp)%>
        </div>
        <div class="editor-field">
            <%: Html.TextBoxFor(model => model.Problem.RequestedFollowUp, new { @class = "dateTimePicker" })%>
            <%: Html.ValidationMessageFor(model => model.Problem.RequestedFollowUp)%>
        </div>

        <div class="editor-label">
            <%: Html.LabelFor(model => model.Problem.Users)%>
        </div>
        <div class="editor-field">
            <%: Html.ListBoxFor(model => model.Problem.Users, Model.ProblemUsers, new { @class = "multiselect" })%>
            <%: Html.ValidationMessageFor(model => model.Problem.Users)%>
        </div>

        <p>
            <input type="submit" class="button" value="Save" />
        </p>

<% } %>

However when I submit the form the [HttpPost] Edit controller action is entered but with null for the majority of values…

[HttpPost]
    public ActionResult Edit(Problem problemValues)
    {
        try
        {
            MembershipUser myObject = Membership.GetUser();
            String UserId = myObject.ProviderUserKey.ToString();

            Problem problem = problemValues.ProblemId == 0
                ? new Problem()
                : sqlProblemRepository.Problems(UserId).First(p => p.ProblemId == problemValues.ProblemId);
            TryUpdateModel(problem);

            if (ModelState.IsValid)
            {
                sqlProblemRepository.SaveProblem(problem);
                TempData["message"] = problem.ProblemId + " has been saved.";

                if (Request.IsAjaxRequest())
                {
                    return Json(problem);
                }

                return RedirectToAction("Details", "Student", new { problem.StudentId });
            }
            else
                return View(problem);
        }
        catch (Exception ex)
        {
            if (Request.IsAjaxRequest())
            {
                return Json(null);
            }
            else
            {
                TempData["message"] = "Record Not Found.";
                return RedirectToAction("Index");
            }
        }
    }

Any Ideas on this would be appreciated it appears to happen on most of my forms where I have dropdowns however I don’t understand why all the values are null even the non-dropdown fields.

Thanks in advance…

Jonathan

Answer 1

I would recommend you to keep your repositories separate from the model. This way all you pass to the view is the model. Neither the View nor the ViewModel should need any repository. The way it works is the controller uses a repository to fetch the model and pass this model to the view:

public ViewResult Create()
{
    string username = User.Identity.Name;
    Problem model = someRepository.FetchModel(username);
    ProblemViewModel viewModel = someMapper.ConvertToViewModel(model);

    return View("Edit", viewModel);
}

And the submit action:

[HttpPost]
public ViewResult Create(ProblemViewModel viewModel)
{
    // viewModel will contain all the fields that you have corresponding
    // inputs in the View
    ...
}