Question

The code below is not showing my errors in the view, how do I ensure my errors display in the view?

//Note I throw a rules exception if something goes wrong somewhere, if so I copy the errors onto the modelstate

    [HttpPost]
    public RedirectToRouteResult TaskDueDate(int id, int taskid)
    {

        var duedate = Request.Form["duedate"];
        var duetime = Request.Form["duetime"];

        try
        {
            var newduedate = DateHelper.GoodDate(duedate, duetime);
            _service.SetTaskDueDate(id, taskid, newduedate);

            this.FlashInfo("success, task due date has been updated...");
        }
        catch (RulesException ex)
        {
            ex.CopyTo(ModelState);
        }

        return RedirectToAction("TaskDetail");
    }

ex.CopyTo extension method:

public static void CopyTo(this RulesException ex, ModelStateDictionary modelstate)
    {
        CopyTo(ex,modelstate,null);
    }

    public static void CopyTo(this RulesException ex, ModelStateDictionary modelstate, string prefix)
    {
        prefix = string.IsNullOrEmpty(prefix) ? "" : prefix + ".";
        foreach (var propertyerror in ex.Errors)
        {
             string key = ExpressionHelper.GetExpressionText(propertyerror.Property);
            modelstate.AddModelError(prefix + key, propertyerror.Message);
        }
    }

In my view I basically have:

        <div id="Errors">
            <span id="ServerResponse"></span>
            <%= Html.ValidationSummary(false, "")%>
        </div>

I think the model state gets cleared and no errors remain on a redirect???

Answer 1

Yes, a redirect is a response to the browser that tells it to make a new request, so any context that you have is lost.

You could show an error page when there is anything to display on it:

if (ModelState.Count > 0) {
  return View("ErrorPage");
} else {
  return RedirectToAction("TaskDetail");
}

You would need to change the return type of your action method to the base class AcionResult to return different kinds of action results.