Our site editors can include a macro inside the RTE to include a form to participate in a competition or register for an event.

This macro inherits from PartialViewMacroPage and inside the partial an child action is rendered. This child action contains a form and after posting to a SurfaceController I return to CurrentUmbracoPage() when ModelState is invalid. I also add a message to the ViewBag.

But both ModelState and ViewBag are lost as soon as I return to the PartialViewMacroPage.

I tried this solution but the ParentActionViewContext is null inside the PartialViewMacroPage.

I have a working solution using session variables and merging ModelState but I'm hoping someone has a more clean solution.