When you use a complex hierarchic Model like :
Model
+--InvoiceHeader
| +-- Address Sender
| +-- Address Recipient
+--List<DetailRow>

       +-- DetailRow

I build
View Invoice
+--InvoiceHeader_TemplateEditor
| +-- Address_TemplateEditor
| +-- Address_TemplateEditor
+--List<DetailRow>

       +-- DetailRow_TemplateEditor

To update keeping the MVC spirit, I also build some partial view for me to rebuild server side hierarchy like that :

_Adress_Updater
+--Address_TemplateEditor

So, if I update Address server side and I regenerate view as string, MVC will automatically generate name and id hierarchy as in the first call, then, I just have to update the div I want to update with de string partial view rendered server side and transfered client side in a JSon Data Bag.

This technique was working in MVC 3 now it fails in MVC 4.

There is multiple RenderViewToString on the internet I tested all, same result.

I also make an other try :

I rendered the partial view but I replaced a textarea generated by @Html.Textareafor(m => m.MyField) by
<div> @Model.MyField </div> It works.

I fell the problem seems to have static variables not reinitialized or something like that.

If you want, you can add me to the contributors, I could try to understand and fix the bug because it's very important for my open source framework.

Awating your reaction,

Best regards

Laurent

    protected string RenderPartialViewToString(string viewName, object model)
    {
        string toReturn;
        if (string.IsNullOrEmpty(viewName))
            viewName = ControllerContext.RouteData.GetRequiredString("action");

        ViewData.Model = model;

        using (StringWriter sw = new StringWriter())
        {
            ViewEngineResult viewResult = ViewEngines.Engines.FindPartialView(ControllerContext, viewName);
            ViewContext viewContext = new ViewContext(ControllerContext, viewResult.View, ViewData, TempData, sw);
            viewResult.View.Render(viewContext, sw);
            toReturn = sw.GetStringBuilder().ToString();
            //toReturn = RenderView(viewContext);
            return toReturn;

        }
    }