How can I use an action filter in ASP.NET MVC to route to a different view but using the same URL? - asp.net-mvc

Question

Is it possible to make a filter that, after a controller action has been (mostly) processed, checks for a certain test condition and routes to a different view transparently to the user (i.e., no change in the URL)?
Here would be my best guess at some pseudocode:
public override void OnResultExecuting(ResultExecutingContext filterContext)
{
// If some condition is true
// Change the resulting view resolution to XYZ
base.OnResultExecuting(filterContext);
}

Answer 1

filterContext.Result = new ViewResult
{
ViewName = "~/Views/SomeController/SomeView.cshtml"
};
This will short-circuit the execution of the action.

Answer 2

also you can return view as from your action
public ActionResult Index()
{
return View(#"~/Views/SomeView.aspx");
}

Answer 3

This is what I ended up doing, and wrapped up into a reusable attribute and the great thing is it retains the original URL while redirecting (or applying whatever result you wish) based on your requirements:
public class AuthoriseSiteAccessAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
base.OnActionExecuting(filterContext);
// Perform your condition, or straight result assignment here.
// For me I had to test the existance of a cookie.
if (yourConditionHere)
filterContext.Result = new SiteAccessDeniedResult();
}
}
public class SiteAccessDeniedResult : ViewResult
{
public SiteAccessDeniedResult()
{
ViewName = "~/Views/SiteAccess/Login.cshtml";
}
}
Then just add the attribute [SiteAccessAuthorise] to your controllers you wish to apply the authorisation access to (in my case) or add it to a BaseController. Make sure though the action you are redirecting to's underlying controller does not have the attribute though, or you'll be caught in an endless loop!

Answer 4

I have extended the AuthorizeAttribute of ASP.NET MVC action filter as DCIMAuthorize, in which I perform some security checks and if user is not authenticated or authorized then action filter will take user to access denied page. My implementation is as below:
public class DCIMAuthorize : AuthorizeAttribute
{
public string BusinessComponent { get; set; }
public string Action { get; set; }
public bool ResturnJsonResponse { get; set; }
public bool Authorize { get; set; }
public DCIMAuthorize()
{
ResturnJsonResponse = true;
}
protected override bool AuthorizeCore(HttpContextBase httpContext)
{
try
{
//to check whether user is authenticated
if (!httpContext.User.Identity.IsAuthenticated)
return false;
//to check site level access
if (HttpContext.Current.Session["UserSites"] != null)
{
var allSites = (VList<VSiteList>)HttpContext.Current.Session["UserSites"];
if (allSites.Count <= 0)
return false;
}
else
return false;
// use Authorize for authorization
Authorize = false;
string[] roles = null;
//get roles for currently login user
if (HttpContext.Current.Session["Roles"] != null)
{
roles = (string[])HttpContext.Current.Session["Roles"];
}
if (roles != null)
{
//for multiple roles
string[] keys = new string[roles.Length];
int index = 0;
// for each role, there is separate key
foreach (string role in roles)
{
keys[index] = role + "-" + BusinessComponent + "-" + Action;
index++;
}
//access Authorization Details and compare with keys
if (HttpContext.Current.Application["AuthorizationDetails"] != null)
{
Hashtable authorizationDetails = (Hashtable)HttpContext.Current.Application["AuthorizationDetails"];
bool hasKey = false;
foreach (var item in keys)
{
hasKey = authorizationDetails.ContainsKey(item);
if (hasKey)
{
Authorize = hasKey;
break;
}
}
}
}
return base.AuthorizeCore(httpContext);
}
catch (Exception)
{
throw;
}
}
public override void OnAuthorization(AuthorizationContext filterContext)
{
try
{
filterContext.Controller.ViewData["ResturnJsonResponse"] = ResturnJsonResponse;
base.OnAuthorization(filterContext);
if (!filterContext.HttpContext.User.Identity.IsAuthenticated)
{
// auth failed, redirect to login page
filterContext.Result = new HttpUnauthorizedResult();
return;
}
if (!Authorize)
{
//Authorization failed, redirect to Access Denied Page
filterContext.Result = new RedirectToRouteResult(
new RouteValueDictionary{{ "controller", "Base" },
{ "action", "AccessDenied" }
//{ "returnUrl", filterContext.HttpContext.Request.RawUrl }
});
}
}
catch (Exception)
{
throw;
}
}
}

Answer 5

You Can Also Save All Route File Path in a Static And Use it Like This :
public static class ViewPath
{
public const string SomeViewName = "~/Views/SomeViewName.cshtml";
//...
}
And into Your ActionFilter :
context.Result = new ViewResult()
{
ViewName = ViewPath.SomeViewName /*"~/Views/SomeViewName.cshtml"*/
};