Question

I have several forms, all which require a checkbox for each province/state. Therefore, I’ve made a partial view to render the checkboxes inside a form to promote code re-use. But when the user submits the form to a controller method, the RegionsViewModel does not get binded. The overall question is, how can I get multiple forms to share a partial view and view model?

Here’s a sample code of my situation
Models

public class Form1ViewModel
{
    /* Some properties */
    public RegionsViewModel Regions {set; get;}
}

public class Form2ViewModel
{
    /* Some properties */
    public RegionsViewModel Regions {set; get;}
}

public class Form3ViewModel
{
    /* Some properties */
    public RegionsViewModel Regions {set; get;}
}

public class RegionsViewModel
{
    public bool ON {set; get;}
    public bool QC {set; get;}
    /* this continues for all provinces and states */
}

Controller

[HttpPost]
public ActionResult Form(Form1VewModel model) {

    //All properties except for model.RegionViewModel does not bind properly to the submitted form :(
}

Form1ViewModel.aspx

<% using (Html.BeginForm())
    {%>
    <!-- Binds some property -->
    <% Html.RenderPartial("Controls/RegionSelector", Model.Regions); %>
    <input type="submit" value="Submit Form!" />
<%}%>

Controls/RegionSelector.ascx

<%=Html.CheckBoxFor(x => x.AvailableProvince_ON> ON
<%=Html.CheckBoxFor(x => x.AvailableProvince_QC> QC
<!-- Binds to all provinces and states -->

Update
Replaced “Model.RegionSelectorVm” with “Model.Region”. Thanks for finding the bug in my demo code Darin Dimitrov.

Answer 1

What is RegionSelectorVm? It seems that this is the type of your partial. Try with editor templates. It’s cleaner:

<% using (Html.BeginForm()) { %>
    <!-- Binds some property -->
    <%= Html.EditorFor(x => x.Regions) %>
    <input type="submit" value="Submit Form!" />
<% } %>

and inside ~/Views/Shared/EditorTemplates/RegionsViewModel.ascx:

<%@ Control 
    Language="C#" 
    Inherits="System.Web.Mvc.ViewUserControl<AppName.Models.RegionsViewModel>" %>
<%= Html.CheckBoxFor(x => x.ON) %> ON
<%= Html.CheckBoxFor(x => x.QC) %> QC

<!-- 
     Continue with inputs for the provinces and states 
     which are part of the RegionsViewModel model 
-->

Now everything should bind correctly.