ASP.NET MVC - add to a viewmodel list and submit

Question

I have an ASP.NET MVC program with an order/odc request form. I have a customer, order and order item model. What I want to do is allow the user to place an order for a list of items to be approved. I have the viewmodel being passed to the form/view with a few fields including a list of order item objects. I am able to dynamically add rows to the table which shows the list of order items but on submit there is nothing in the viewmodel list. What am I doing wrong? How do I pass the items entered into the table to the view so that I can submit to the database?

Controller

    public ActionResult NewOdc()
    {
        var viewModel = new NewOdcViewModel()
        {
            OdcItems = new List<tblOdcItem>() 
        };

        viewModel.OdcItems.Add(new tblOdcItem());

        return View(viewModel);
    }

I call this code from jQuery to add a new item to the list:

    public ActionResult GetView(string rowCount)
    {
        tblOdcItem item = new tblOdcItem();
        return PartialView("_OdcItemEditor", item);
    }

And on submit I call this code:

    [HttpPost]
    public ActionResult NewOdcSubmit(NewOdcViewModel viewModel)
    {
        _context.tblOdcs.Add(new tblOdc());
        ...

I'm using a foreach to go through the list and create a partial for each item.

View:

@using (Html.BeginForm("NewOdcSubmit", "Odc", FormMethod.Post))
{
            if (Model != null)
            {
                @Html.HiddenFor(m => m.OdcItems);
            }

            <div class="panel panel-info">
                <div class="panel-heading">
                    <h2 class="panel-title">Enter New ODC</h2>
                </div>
                <div class="panel-body">
                    @Html.AntiForgeryToken()
                    <div class="form-group">
                        @Html.LabelFor(model => model.User.UserName, new { @class = "col-md-2 col-sm-1 control-label" })
                        <div class="col-md-2 col-sm-3">
                            @Html.TextBoxFor(model => model.User.UserName, new { @Value = ((PM_Portal2020.Models.tblUser)Session["User"]).UserName, @readonly = true })
                        </div>
                        @Html.LabelFor(model => model.User.Phone, new { @class = "col-md-2 col-sm-1 control-label" })
                        <div class="col-md-2 col-sm-3">
                            @Html.TextBoxFor(model => model.User.Phone, new { @Value = ((PM_Portal2020.Models.tblUser)Session["User"]).Phone })
                        </div>
                    </div>
                    <div class="form-group col-md-10 col-sm-12">
                        <label>Expenses</label>
                        <table id="submissionTable" class="table table-bordered">
                            <thead>
                                <tr>
                                    <th>Qty</th>
                                    <th>Description</th>
                                    <th>Estimated Cost</th>
                                </tr>
                            </thead>
                            <tbody>
                                @foreach (PM_Portal2020.Models.tblOdcItem item in Model.OdcItems)
                                {
                                    @Html.Partial("_OdcItemEditor", item)
                                }
                            </tbody>
                        </table>
                        <p>
                            <button id="add" type="button" class="btn btn-primary">Add</button>
                        </p>
                    </div>
                    <div class="form-group col-lg-10 col-sm-12">
                        @Html.LabelFor(model => model.Details, new { @class = "col-md-2 col-sm-1 control-label" })
                        <div class="">
                            @Html.TextAreaFor(model => model.Details, new { @class = "form-control" })
                        </div>
                    </div>
                </div>
                <div class="panel-footer">
                    <div class="">
                        <button type="submit" class="btn btn-success">Save</button>&nbsp;&nbsp;
                        @Html.ActionLink("Back", "Index")
                    </div>
                </div>
            </div>
}

PartialView in Shared folder:

@model PM_Portal2020.Models.tblOdcItem

<tr @Html.Id("tablerow" + Model.ID)>
    <td>
        <div class="editor-field">
            @Html.TextBoxFor(model => model.Quantity, new { @class = "text-box single-line", name = "Quantity[" + Model.ID + "]", type = "text", value = "", required = "required" })
        </div>
    </td>
    <td>
        <div class="editor-field">
            @Html.TextBoxFor(model => model.Description, new { @class = "text-box single-line", name = "Description[" + Model.ID + "]", type = "text", value = "", required = "required", id = "itemDesc" })
        </div>
    </td>
    <td>
        <div class="editor-field">
            @Html.TextBoxFor(model => model.EstimatedCost, new { @class = "text-box single-line", name = "EstimatedCost[" + Model.ID + "]", type = "text", value = "", required = "required" })
        </div>
    </td>
    <td>
        <button type="button" class="btn btn-primary" onclick="removeTr(this);">
            <span class="glyphicon glyphicon-trash"></span>
        </button>
    </td>
</tr>

View Model

public class NewOdcViewModel
{
    public NewOdcViewModel()
    {
    }

    public IList<tblOdcItem> OdcItems { get; set; }
    public string Details { get; set; }
    public int OdcId { get; set; }
    public tblUser User { get; set; }
}

It submits to the controller but the odcitems list is always count = 0. Any help would be great. Thanks

Answer 1

Here is the javascript example, just use this function on add/delete operation to re-arrange name.

function RearangeName(){
        var i = 0;
        $("#submissionTable>tbody>tr").each(function () {
            $(this).find("input").each(function () {
                if ($(this).prop("name").indexOf('Quantity') > 0) {
                    $(this).attr('name', "OdcItems[" + i + "].Quantity");
                }
                if ($(this).prop("name").indexOf('Description') > 0) {
                    $(this).attr('name', "OdcItems[" + i + "].Description");
                }
                if ($(this).prop("name").indexOf('EstimatedCost') > 0) {
                    $(this).attr('name', "OdcItems[" + i + "].EstimatedCost");
                }
            });
            i++;
        });
    }