I've working on a project where I've implemented Route Hijacking on a Template basis with my own custom ViewModel inheriting from RenderModel.

The url displayed to the user is /members/admin/{route parameter}/edit which is rendered successfully via a Controller I have put together that inherits from RenderMvcController. The template displayed contains a simple form which posts to a Controller that inherits from SurfaceController.

If I use a @Html.BeginUmbracoForm form on this template then the post back to the controller is successful however as soon as I change this to a @Ajax.BeginForm the form doesn't appear to submit. When I look at Chrome's console I can see the submit returns a 500 error with a System.NullReferenceException thrown within the ViewModel's default constructor:

public class EditViewModel : RenderModel
{
public EditViewModel() : base(UmbracoContext.Current.PublishedContentRequest.PublishedContent) { }
public EditViewModel(IPublishedContent content) : base(content) { }
}

I'm guessing that as this is an AJAX post that the UmbracoContext is lost so my question is how do I get around this? I could go with one View Model for display purposes that inherits from RenderModel and then a separate one to use for the form post that doesn't inherit from RenderModel but that seems like a bit of a hack.

Any ideas?