Update view when 404 exception

Question

On my code i'm using log4net to log exception and end of the logging i want to update view with proper message view. on my log service update view (actually my code does redirect) my code look like this

private readonly HttpContextBase _httpContext;

public void RedirectToError()
{
    var httpException = _httpContext.Server.GetLastError();
    if (httpException != null && (_httpContext.Server.GetLastError() is HttpException))
    {
        _httpContext.Server.ClearError();
        _httpContext.Response.Redirect("/Error", false);
    }

}

but i actually wants to update the viewresult only like authorized attribute i able to update the viewresult like this

protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext)  
{
    if (filterContext.HttpContext.User.Identity.IsAuthenticated)
    {
        filterContext.Result =  new ViewResult {ViewName = "NoPermissions"};
    }
    else
    {
        // let the base implementation redirect the user
        base.HandleUnauthorizedRequest(filterContext);
    }
}

but nor like filtercontext, how can we update viewresult with httpcontext? if no way to do that with httpcontext how could we achieve this ?

Thanks

Hi there's no problem with above code only I need to update view result without redirecting. Like on second code example. — Gayan, Mar 14 '15 at 03:02

score 1 · Answer 1 · answered Mar 13 '15 at 16:09

It is unclear where the first block of code is and whether the second block even relates to your question (other than a demo). Your question is unclear, so this is a shot in the dark.

One way to pass information from one part of the application to another is to use request caching.

private readonly HttpContextBase _httpContext;

public void RedirectToError()
{
    var httpException = _httpContext.Server.GetLastError();
    if (httpException != null && (_httpContext.Server.GetLastError() is HttpException))
    {
        _httpContext.Server.ClearError();

        // Store the error in the request cache
        _httpContext.Items["LastError"] = httpException;
        _httpContext.Response.Redirect("/Error", false);
    }

}

Then in your Error action method you can access this value.

public ActionResult Error()
{
    // Retrieve the error from the request cache
    Exception lastError = (Exception)this.HttpContext.Items["lastError"];

    // Pass the error message to the view
    ViewBag.Error = lastError.Message;

    return View();
}

Typically, you would just log the error and not show it to the user because of the security implications that can have.

I'm sorry. What I'm saying is I wanted to update the viewresult only. Not to redirect. (Url shouldn't update) second code examples not related to my question. It's only to show you how to achieve my goal with filterContext. Thanks — Gayan, Mar 14 '15 at 02:58

score 0 · Answer 2 · answered Mar 17 '15 at 14:59

You can catch the error in the Application_Error Method in the Global.asax and use the HttpContext to redirect to your page.

Protected void Application_Error(object sender, EventArgs e)
{
        MvcApplication app = (MvcApplication)sender;
        HttpContext context = app.Context;
       Exception exc = Server.GetLastError();
        if (exc.GetType() == typeof(HttpException))
            {
                errorCode = ((HttpException)exc).GetHttpCode();
            }
            else if (exc.GetType() == typeof(Exception))
            {
                errorCode = 500;
            }
            var routeData = new RouteData();
            routeData.Values["controller"] = "{Your Controller}";
            routeData.Values["statusDescription"] = "{Your Description}";
            routeData.Values["action"] = "http500";

            switch (errorCode)
            {
                case 404:
                      Server.ClearError();
                    routeData.Values["action"] = "Your action name";
                    break;
                case 403:

                    Server.ClearError();
                    routeData.Values["action"] = "Your action name";
                    break;
                case 405:

                    Server.ClearError();
                    routeData.Values["action"] = "Your action name";
                    break;
                case 500:

                    Server.ClearError();
                    routeData.Values["action"] = "Your action name";
                    break;
                default:

                    Server.ClearError();
                    routeData.Values["action"] = "Your action name";
                    break;
            }

            IController controller = new ErrorsController();
            controller.Execute(new RequestContext(new HttpContextWrapper(context), routeData));

            Server.ClearError();
    }

Please respond if it helps. :)

score 0 · Answer 3 · edited May 23 '17 at 12:22

0

It looks like you're trying to avoid the 302 before the displaying the error page and just return a 404 with the error...

If you get to a controller method that is returning a ViewResult then you're already past the point at which ASP.NET has determined that it should return a 404 or not.

For 404's in MVC I would use this answer.

edited May 23 '17 at 12:22

Community

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answered Mar 17 '15 at 15:31

Rush Frisby

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Update view when 404 exception

3 Answers3