MVC BeginCollectionItem - asp.net-mvc

Question

I'm having some issue getting my partial view BeginCollectionItem to save to the database. I have a form which has a dynamic number of "sections" that can be added to the page, and within each of these fields there is a text box where the user can enter the section name.
As far as I can tell the BeginCollectionItem within the partial view is working properly, however I cannot post the info to the database. In my other forms I have used a [bind()] to send the data to the database, is it possible to get this into a list and then post that via a bind?
I've included my code below:
The Model:
namespace project.Models.SetupViewModels
{
public class SOPTopTemplateBuilderViewModel
{
public List<Section> Section { get; set; }
}
public class Section {
public int SectionId { get; set; }
public string SectionText { get; set; }
public string TopTempId { get; set; }
}
}
cshtml:
#model IEnumerable<project.Models.SetupViewModels.Section>
#using (Html.BeginForm("SOPTopTemplateBuilder", "Setup", FormMethod.Post))
{
<div class="main-holder" id="theform">
#foreach(var item in Model)
{
#Html.Partial("_SectionCreator", item)
}
</div>
<button id="add" type="button">Add</button>
<div class="form-group submit-row">
<div class="col-12 float-to-right">
<input type="submit" class="btn btn-default" value="continue" />
</div>
</div>
}
#section Scripts {
<script>
$(document).ready(function () {
var url = '#Url.Action("AddSection")';
var form = $('form');
var recipients = $('#theform');
$('#add').click(function() {
$.post(url, function(response) {
recipients.append(response);
// Reparse the validator for client side validation
form.data('validator', null);
$.validator.unobtrusive.parse(form);
});
});
});
</script>
}
Partial View:
#model project.Models.SetupViewModels.Section
#using HtmlHelpers.BeginCollectionItemCore
#using (Html.BeginCollectionItem("Section"))
{
<div class="new-section">
<div>
<p>New Section</p>
#Html.HiddenFor(m => m.SectionId, new { #class="id" })
#Html.EditorFor(m => m.SectionText, new { #class = "form-control limit-form"})
</div>
</div>
}
Controller:
[HttpPost]
public PartialViewResult AddSection()
{
return PartialView("_SectionCreator", new Section());
}
[HttpGet]
public ActionResult SOPTopTemplateBuilder(){
List<Section> model = new List<Section>();
return View(model);
}
[HttpPost]
public ActionResult SOPTopTemplateBuilder(IEnumerable<Section> soptop)
{
if (ModelState.IsValid)
{}
return View(soptop);
}

Answer 1

Your use of Html.BeginCollectionItem("Section") perpends Section[xxxx] to the name attribute (where xxxx is a Guid) so that you generating inputs with
<input name="Section[xxxx].SectionId" .... />
which posts back to a model containing a collection property named Sections.
Since you already have a model with that property, you can change the POST method to
[HttpPost]
public ActionResult SOPTopTemplateBuilder(SOPTopTemplateBuilderViewModel soptop)
other options include
Using your existing POST method and omitting the "Section" prefix
using Html.BeginCollectionItem("") which will generate
name="[xxxx].SectionId"
Changing the POST method signature to public ActionResult
SOPTopTemplateBuilder(IEnumerable<Section> section) (where the
name of the parameter matches the name of the prefix)
Using a BindAttribute to 'strip' the prefix from the form values
public ActionResult SOPTopTemplateBuilder([Bind(Prefix = "Section")]IEnumerable<Section> soptop)
As a side note, your editing data, so you should always use a view model (say public class SectionViewModel) rather than using data models in your view. - What is ViewModel in MVC?