Managed to hack something together.  Although I'd like to know the correct way to do something like this.

This is my controller

[HttpPost]
public ActionResult HandleDropDownPostback(ConstituencyModel model)
{
    if (ModelState.IsValid == false)
    {
        return CurrentUmbracoPage();
    }

    var db = ApplicationContext.Current.DatabaseContext.Database;

    Constituency constituency = db.Query<Constituency>("SELECT * FROM bcg_Constituencies WHERE ConstituencyName = @0", model.ConstituencySelected).First();
    if (constituency != null)
    {
        TempData["constituency"] = constituency;
    }

    var ccgs = db.Query<CcgModel>("SELECT * FROM bcg_CCGs LEFT JOIN bcg_CcgContactDetails ON bcg_CCGs.CCGName = bcg_CcgContactDetails.CCGName WHERE ConstituencyCrossover = @0", model.ConstituencySelected);
    TempData["ccgs"] = ccgs;

    return RedirectToCurrentUmbracoPage();
}

And my partial view

@using (Html.BeginUmbracoForm<ConstituencySurfaceController>("HandleDropDownPostback"))
{
    <div class="editor-row">
        @Html.DropDownListFor(model => model.ConstituencySelected, Model.ConstituencyList, "Select your constituency")

        <input type="submit" value="Find CCG Details" class="btn auto" />
        <div>
        @Html.ValidationMessageFor(model => model.ConstituencySelected)
        </div>
    </div>

    if (TempData["constituency"] != null && TempData["ccgs"] != null)
    {
        Constituency constituency = (Constituency)TempData["constituency"];

        <div class="constituency-details">
            <p><strong>Constituency:</strong> @constituency.ConstituencyName<br />
                <strong>MP:</strong> @constituency.FirstName @constituency.LastName (@constituency.Party)
            </p>
        </div>

        IEnumerable<CcgModel> ccgs = (IEnumerable<CcgModel>)TempData["ccgs"];

        if (ccgs.Count() > 0)
        {
            <table class="ccg-table">
                <tr>
                    <th>CCG</th>
                    <th style="width:230px;">Contact Phone No</th>
                    <th style="width:40px;">Live</th>
                </tr>
            @foreach (CcgModel item in ccgs)
            {
                <tr class="@(item.Live ? "live" : "notlive")">
                    <td>@item.CCGName</td>
                    <td>@(!string.IsNullOrEmpty(item.Telephone) ? item.Telephone : "N/A")</td>
                    <td>@(item.Live ? "Yes" : "No")</td>
                </tr>
            }
            </table>
        }
        else
        {
            <p>There are no CCGs within the selected constituency.</p>
        }
    }
}

Firstly i would not use umbracoBeginForm or RedirectToPage

I would use standard Html and Ajax posts

It sounds like you want to use AJAX to re-render a portion of the page on post back?  Is this correct.

Are you going to your controller from a view or partial view?  If you go from a view you need to go back to a view, if you go from a partial you need to go back to a partial, thus you need AJAX to rerender that partial.

I think this is where your problem is.  You are posting back a partial view result using a HTML POST which is re-rendeing the page with just the partial and not the whole page with everything.

Does that make sense?

Charlie :)

It was my intention to have an AJAX post that renders a section on the page.  But as I didn't know how to call the controller from the javascript I thought just making a simple for that posts back to the same page would be easier.  Don't think it was though :p

What I wanted was the MVC equivelant of an auto postback drop down list where upon selecting an item in the drop down the details for that item are shown on the same page.  I've not done a lot of MVC though and I had a (very) tight deadline so I couldn't take my time and learn how to do it properly.

If I'm honest I don't really understand what you said.  It makes common sense which is a start I suppose ;)

The only thing I can suggest is to make sure your controller inherits from SurfaceController.

public class ConstituencySurfaceController : Umbraco.Web.Mvc.SurfaceController

Not sure why TempDate would be null as I don't really understand how my code works :p

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