signalR send partial view result string via hub - asp.net-mvc

Question

I need to be able to return partial view as string in my MVC app via signalR. I'm using hubs.
I'm using the following method to return a partial view string (from here):
public static string RenderPartialView(string controllerName, string partialView, object model)
{
var context = httpContextBase as HttpContextBase;
var routes = new RouteData();
routes.Values.Add("controller", controllerName);
var requestContext = new RequestContext(context, routes);
string requiredString = requestContext.RouteData.GetRequiredString("controller");
var controllerFactory = ControllerBuilder.Current.GetControllerFactory();
var controller = controllerFactory.CreateController(requestContext, requiredString) as ControllerBase;
controller.ControllerContext = new ControllerContext(context, routes, controller);
var ViewData = new ViewDataDictionary();
var TempData = new TempDataDictionary();
ViewData.Model = model;
using (var sw = new StringWriter())
{
var viewResult = ViewEngines.Engines.FindPartialView(controller.ControllerContext, partialView);
var viewContext = new ViewContext(controller.ControllerContext, viewResult.View, ViewData, TempData, sw);
viewResult.View.Render(viewContext, sw);
return sw.GetStringBuilder().ToString();
}
}
In order for this method to work I need HttpContext.Current therefore in my OnConnected (I noticed that this always exists) I set it like so:
public class TaskActionStatus : Hub
{
private static HttpContextBase httpContextBase;
...
public override Task OnConnected()
{
httpContextBase = new HttpContextWrapper(HttpContext.Current) as HttpContextBase;
...
and then I use it in my RenderPartialView method:
var context = httpContextBase as HttpContextBase;
This way I always have access to current HttpContext. However, I noticed that sometimes my static copy of HttpContext is null. Why is that?.
What's the best approach here?
Is there a way to render partial view without HttpContext?

Answer 1

I used fake http context to generate view:
public static string GetRazorViewAsString(object model, string filePath)
{
HttpContext httpContext = MockHelper.FakeHttpContext();
var st = new StringWriter();
var context = new HttpContextWrapper(httpContext);
var routeData = new RouteData();
var controllerContext = new ControllerContext(new RequestContext(context, routeData), new FakeController());
var razor = new RazorView(controllerContext, filePath, null, false, null);
razor.Render(
new ViewContext(controllerContext, razor, new ViewDataDictionary(model), new TempDataDictionary(), st),
st);
return st.ToString();
}
#endregion
}
public class FakeController : Controller
{
}
public class MockHelper
{
#region Public Methods and Operators
public static HttpContext FakeHttpContext()
{
var httpRequest = new HttpRequest(string.Empty, "http://novomatic/", string.Empty);
var stringWriter = new StringWriter();
var httpResponce = new HttpResponse(stringWriter);
var httpContext = new HttpContext(httpRequest, httpResponce);
var sessionContainer = new HttpSessionStateContainer(
"id",
new SessionStateItemCollection(),
new HttpStaticObjectsCollection(),
10,
true,
HttpCookieMode.AutoDetect,
SessionStateMode.InProc,
false);
httpContext.Items["AspSession"] =
typeof(HttpSessionState).GetConstructor(
BindingFlags.NonPublic | BindingFlags.Instance,
null,
CallingConventions.Standard,
new[] { typeof(HttpSessionStateContainer) },
null).Invoke(new object[] { sessionContainer });
return httpContext;
}
#endregion
}