Accessing sub model with HTML Helper

Question

I have an object which looks like this:

public class QuestionSet
{
    [Required]
    public int Id { get; set; }

    [Required]
    public int ConferenceId { get; set; }

    [Required]
    public string Name { get; set; }

    public virtual ICollection<RegistrationQuestion> Questions { get; set; }

    public virtual ICollection<QuestionSetAssignee> QuestionSetAssignees { get; set; }

    public QuestionSet()
    {

    }

    public QuestionSet(int conferenceId)
    {
        this.ConferenceId = conferenceId;
    }
}

And the model for RegistrationQuestion looks like this:

public class RegistrationQuestion
{
    [Required]
    public int Id { get; set; }

    [Required]
    public int QuestionSetId { get; set; }

    [Required]
    public string QuestionText { get; set; }
}

When creating a QuestionSet, I would like to create its related RegistrationsQuestions at the same time. However, the Razor Html Helpers don't let me drill down to that level.

I can do this:

@Html.LabelFor(model => model.Questions)

but not this (and this is what I want to be able to do):

@Html.LabelFor(model => model.Questions.QuestionText)

Any guidance on how to achieve this?

Answer 1

I solved this by creating a partial view for the sub model and then dynamically inserting those (with JavaScript/jQuery) as needed.

Answer 2

You can get it working like this. I made small changes to your model, instead of using ICollection<>, I used IList<> which have indexer support and can easily be iterated.

public class QuestionSet
{
    [Required]
    public int Id { get; set; }

    [Required]
    public int ConferenceId { get; set; }

    [Required]
    public string Name { get; set; }

    public virtual IList<RegistrationQuestion> Questions { get; set; }
}

public class RegistrationQuestion
{
    [Required]
    public int Id { get; set; }

    [Required]
    public int QuestionSetId { get; set; }

    [Required]
    public string QuestionText { get; set; }
}

I add following sample data in controller action -

    public ActionResult Index()
    {
        QuestionSet q = new QuestionSet();
        q.Questions = new List<RegistrationQuestion>();
        q.Questions.Add(new RegistrationQuestion() { QuestionText = "hi1?" });
        q.Questions.Add(new RegistrationQuestion() { QuestionText = "hi2?" });
        q.Questions.Add(new RegistrationQuestion() { QuestionText = "hi3?" });
        return View(q);
    }

And then in your view, you can have iteration in following way -

@for (int i = 0; i < Model.Questions.Count; i++)
{
    @Html.LabelFor(model => model.Questions[i].QuestionText, Model.Questions[i].QuestionText)
    @Html.EditorFor(model => model.Questions[i].QuestionText)
    <br/>
}

Output -