asp.net mvc parent child view with parent view updating children

Question

I am using a partial view to create a parent child view. What I would ideally like is the submit button on the parent view to save the child values.

I have the following model.

public class Course
{
    public int CourseId { get; set; }
    public string Name { get; set; }
    public int Par { get; set; }
    public string Tee { get; set; }
    public decimal Rating { get; set; }
    public virtual IEnumerable<CourseHole> Holes { get; set; }

    public static Course Create()
    {
        var course = new Course();
        course.Par = 72;
        var holes = new List<CourseHole>();
        for (int i = 0; i < 18; i++)
        {
            holes.Add(new CourseHole() { Course = course, Number = i + 1, Par = 4 });
        }
        course.Holes = holes;
        return course;
    }
}

public class CourseHole
{
    public int CourseHoleId { get; set; }
    public int Number { get; set; }
    public int Par { get; set; }
    public int Length { get; set; }
    public int Ranking { get; set; }
    public Course Course { get; set; }
}

And the following parent view.

@model Golf_Statz.Models.Course

@{
    ViewBag.Title = "Create";
}

<h2>Create</h2>


@using (Html.BeginForm())
{
    @Html.AntiForgeryToken()

    <div class="form-horizontal">
        <h4>Course</h4>
        <hr />
        @Html.ValidationSummary(true, "", new { @class = "text-danger" })
        <div class="form-group">
            @Html.LabelFor(model => model.Name, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-4">
                @Html.EditorFor(model => model.Name, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Name, "", new { @class = "text-danger" })
            </div>

            @Html.LabelFor(model => model.Par, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-4">
                @Html.EditorFor(model => model.Par, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Par, "", new { @class = "text-danger" })
            </div>
        </div>

        <div class="form-group">
            @Html.LabelFor(model => model.Tee, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-4">
                @Html.EditorFor(model => model.Tee, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Tee, "", new { @class = "text-danger" })
            </div>

            @Html.LabelFor(model => model.Rating, htmlAttributes: new { @class = "control-label col-md-2" })
            <div class="col-md-4">
                @Html.EditorFor(model => model.Rating, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Rating, "", new { @class = "text-danger" })
            </div>
        </div>

        @foreach (Golf_Statz.Models.CourseHole hole in Model.Holes)
        {
            @Html.Partial("CreateHole", hole)
        }

        <div class="form-group">
            <div class="col-md-offset-2 col-md-10">
                <input type="submit" value="Create" class="btn btn-default" />
            </div>
        </div>
    </div>
}



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

@section Scripts {
    @Scripts.Render("~/bundles/jqueryval")
}

And the following partial view.

@model Golf_Statz.Models.CourseHole

@{
    ViewBag.Title = "CreateHole";
}

@using (Html.BeginForm()) 
{
    @Html.AntiForgeryToken()

    <div class="form-horizontal" id="CreateHole-" + model.CourseHoleId>
        @Html.ValidationSummary(true, "", new { @class = "text-danger" })
        <div class="form-group">
            <div class="col-md-2 col-md-offset-2">
                <p>@Model.Number</p>
            </div>
            <div class="col-md-2">
                @Html.EditorFor(model => model.Par, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Par, "", new { @class = "text-danger" })
            </div>
            <div class="col-md-2">
                @Html.EditorFor(model => model.Length, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Length, "", new { @class = "text-danger" })
            </div>
            <div class="col-md-2">
                @Html.EditorFor(model => model.Ranking, new { htmlAttributes = new { @class = "form-control" } })
                @Html.ValidationMessageFor(model => model.Ranking, "", new { @class = "text-danger" })
            </div>
        </div>
    </div>
}

@section Scripts {
    @Scripts.Render("~/bundles/jqueryval")
}

My controller methods are.

// GET: Course/Create
        public ActionResult Create()
        {           
            return View(Course.Create());
        }

        // POST: Course/Create
        // To protect from overposting attacks, please enable the specific properties you want to bind to, for 
        // more details see http://go.microsoft.com/fwlink/?LinkId=317598.
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create([Bind(Include = "CourseId,Name,Par,Tee,Rating")] Course course)
        {
            if (ModelState.IsValid)
            {
                db.Courses.Add(course);
                foreach (var hole in course.Holes)
                {
                    db.CourseHoles.Add(hole);
                }
                db.SaveChanges();
                return RedirectToAction("Index");
            }

            return View(course);
        }

No matter what I seem to do course.Holes in the HttpPost Create method is always null. I think I want something similar to this but it's for editing and I want it for creating. Any help would be greatly appreciated as this is my first mvc project.

Answer 1

In your case you have two forms! Razor would generate this

<form>
    <form>
    </form>
 </form>

remove @using (Html.BeginForm()) {} from the partial view

Answer 2

Your foreach loop is generating duplicate id attributes (invalid html) and name attributes which have no relationship to your model. Change the partial to an EditorTemplate

/Views/Shared/EditorTemplates/CourseHole.cshtml

and remove the BeginForm, AntiForgeryToken and scripts

@model Golf_Statz.Models.CourseHole
<div class="form-horizontal" id="CreateHole-" + model.CourseHoleId>
    <div class="form-group">
        <div class="col-md-2 col-md-offset-2">
            <p>@Model.Number</p>
        </div>
        <div class="col-md-2">
            @Html.EditorFor(model => model.Par, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.Par, "", new { @class = "text-danger" })
        </div>
        <div class="col-md-2">
            @Html.EditorFor(model => model.Length, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.Length, "", new { @class = "text-danger" })
        </div>
        <div class="col-md-2">
            @Html.EditorFor(model => model.Ranking, new { htmlAttributes = new { @class = "form-control" } })
            @Html.ValidationMessageFor(model => model.Ranking, "", new { @class = "text-danger" })
        </div>
    </div>
</div>

and then in the main view

@Html.EditorFor(m => m.Holes)

The EditorFor() method will correctly generate the html for binding to a collection, for example

<input name="Holes[0].Par" ...>
<input name="Holes[1].Par" ...>

You also need to remove the [Bind] attribute since you are excluding property Holes, and you seem to want to bind to all properties anyway.

Side note: You do not generate an input for the hole CourseHoleId or Number properties so these wont post back.