I'm using the ExceptionFilterAttribute, like this:
public class HttpExceptionFilter : ExceptionFilterAttribute
{
public override void OnException(HttpActionExecutedContext context)
{
var httpEx = context.Exception as HttpException;
if (httpEx != null)
{
var message = new HttpResponseMessage((HttpStatusCode) httpEx.GetHttpCode());
context.Response = message;
context.Exception = null;
}
}
}
So, I need to go through this filter, but if it enters the 'if' condition,
I'd like it to do not enter any more filters, that's why I did the last line:
context.Exception = null;
But it's not working. How can I do that?
Thanks a lot!
Using FilterAttribute and IExceptionFilter and implementing the OnException with the ExceptionContext parameter would avoid any other filters if an exception is raised.
public class MyErrorHandlerAttribute : FilterAttribute, IExceptionFilter
{
public void OnException(ExceptionContext filterContext)
{
if (!filterContext.ExceptionHandled)
{
//Write more exception processing code if required
filterContext.ExceptionHandled = true;
filterContext.Result = new ViewResult { ViewName = "Error" };
}
}
}
Tested this with OnResultExecuted. Didn't fire when an exception got handled by the aforementioned implementaion.
Related
I'm trying to pass a URL for a background image to my _Layout.cshtml,
public HomeController()
{
this.ViewData["BackgroundImage"] = "1920w/Stipula_fountain_pen.jpg";
}
and
<body style="background-image: url(#(string.Format("assets/images/{0}", ViewData["BackgroundImage"])))">
...
</body>
but ViewData is always empty inside _Layout.cshtml. Is that working as intended? I'd rather not go down the BaseViewModel/BaseController route as that feels like overkill.
EDIT: It seems as if ViewData set in the constructor isn't actually used, because once an action is executing the collection is empty. If I set ViewData inside the action then that data is passed on to _Layout.cshtml - feels like a bug to me.
You can use an action filter to set ViewData for all controller actions:
public class SetBackgroundUrlAttribute : ActionFilterAttribute
{
public override void OnActionExecuted(ActionExecutedContext filterContext)
{
base.OnActionExecuted(filterContext);
var result = filterContext.Result as ViewResult;
if (result != null)
{
result.ViewData["BackgroundImage"] = "1920w/Stipula_fountain_pen.jpg";
}
}
}
[SetBackgroundUrl]
public HomeController()
{
}
Or just override OnActionExecuted method of the controller:
public override void OnActionExecuted(ActionExecutedContext context)
{
base.OnActionExecuted(context);
var result = context.Result as ViewResult;
if (result != null)
{
result.ViewData["BackgroundImage"] = "1920w/Stipula_fountain_pen.jpg";
}
}
Expanding on adem caglin's answer I went with this filter attribute, which can take an arbitrary URL:
[AttributeUsage(AttributeTargets.Class|AttributeTargets.Method, AllowMultiple = false)]
public class SetBackgroundUrlAttribute : ActionFilterAttribute
{
public override void OnActionExecuted(ActionExecutedContext filterContext)
{
base.OnActionExecuted(filterContext);
if (!string.IsNullOrWhiteSpace(this.Url))
{
var result = filterContext.Result as ViewResult;
if (result != null)
result.ViewData["BackgroundImage"] = this.Url;
}
}
public string Url { get; set; }
}
and is used like so:
[SetBackgroundUrl(Url = "1920w/Stipula_fountain_pen.jpg")]
public class HomeController : Controller
{
...
}
I've got this code.
public ActionResult Index()
{
ReceiptModel model = new ReceiptModel();
try
{
model = new ReceiptModel(context);
}
catch (BussinessException bex)
{
ModelState.AddModelError("Index", bex.MessageToDisplay);
return View("Index");
}
return View(model);
}
BussinesException ir returned from database and then displayed for user. I have to put on every controller method try-catch statement, which is a bit tedious. Is there any easier way how to handle these exceptions?
P.S. All other exceptions are handled with HandleExceptionAttribute
UPDATE:
I used Floradu88 approach. So Now i have something like this.
public sealed class HandleBussinessExceptionAttribute : HandleErrorAttribute, IExceptionFilter
{
public override void OnException(ExceptionContext filterContext)
{
filterContext.Controller.TempData["UnhandledException"] = filterContext.Exception;
filterContext.ExceptionHandled = true;
((Controller)filterContext.Controller).ModelState.AddModelError(
((BussinessException)filterContext.Exception).Code.ToString(),
((BussinessException)filterContext.Exception).MessageToDisplay
);
filterContext.Result = new ViewResult
{
ViewName = this.View,
TempData = filterContext.Controller.TempData,
ViewData = filterContext.Controller.ViewData,
};
}
}
and on Controller action i put
[HandleBussinessExceptionAttribute(Order = 2, ExceptionType = typeof(BussinessException), View = "Login")]
i also tried in exception handler:
filterContext.Result = new RedirectToRouteResult(new RouteValueDictionary(filterContext.RouteData));
and then handle error in action with ModelState.IsValid but values to action comes null. So for now i use first approach. When i have a bit more time i'll try to fix second approach.
Please read the documentation on this part:
http://msdn.microsoft.com/en-us/library/gg416513%28v=vs.98%29.aspx
http://www.asp.net/web-api/overview/web-api-routing-and-actions/exception-handling
http://www.asp.net/mvc/tutorials/older-versions/controllers-and-routing/understanding-action-filters-cs
Too much content to be posted here:
public class NotImplExceptionFilterAttribute : ExceptionFilterAttribute
{
public override void OnException(HttpActionExecutedContext context)
{
if (context.Exception is NotImplementedException)
{
context.Response = new HttpResponseMessage(HttpStatusCode.NotImplemented);
}
}
}
And your controller:
public class ProductsController : ApiController
{
[NotImplExceptionFilter]
public Contact GetContact(int id)
{
throw new NotImplementedException("This method is not implemented");
}
}
According to this post, Create a custom binder and put the model in TempData:
public class AppBinder : DefaultModelBinder
{
protected override void OnModelUpdated(ControllerContext controllerContext, ModelBindingContext bindingContext)
{
base.OnModelUpdated(controllerContext, bindingContext);
controllerContext.Controller.TempData["model"] = bindingContext.Model;
}
}
Register it in global.asax:
ModelBinders.Binders.DefaultBinder = new AppBinder();
Create a BaseController and override the OnException:
protected override void OnException(ExceptionContext filterContext)
{
filterContext.ExceptionHandled = true;
this.ModelState.AddModelError(string.Empty, filterContext.Exception.Message);
filterContext.Result = new ViewResult
{
ViewName = filterContext.RouteData.Values["action"].ToString(),
TempData = filterContext.Controller.TempData,
ViewData = filterContext.Controller.ViewData
};
base.OnException(filterContext);
}
All Actions int The Controllers which inherited from this base controller will show their unhandled exceptions their own view in validation summery (remember to have
#Html.ValidationSummary(true)
in page). it works for me, hope works for you too!
I have set up a global filter for all my controller actions in which I open and close NHibernate sessions. 95% of these action need some database access, but 5% don't. Is there any easy way to disable this global filter for those 5%. I could go the other way round and decorate only the actions that need the database, but that would be far more work.
You could write a marker attribute:
public class SkipMyGlobalActionFilterAttribute : Attribute
{
}
and then in your global action filter test for the presence of this marker on the action:
public class MyGlobalActionFilter : ActionFilterAttribute
{
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
if (filterContext.ActionDescriptor.GetCustomAttributes(typeof(SkipMyGlobalActionFilterAttribute), false).Any())
{
return;
}
// here do whatever you were intending to do
}
}
and then if you want to exclude some action from the global filter simply decorate it with the marker attribute:
[SkipMyGlobalActionFilter]
public ActionResult Index()
{
return View();
}
Though, the accepted answer by Darin Dimitrov is fine and working well but, for me, the simplest and most efficient answer found here.
You just need to add a boolean property to your attribute and check against it, just before your logic begins:
public class DataAccessAttribute: ActionFilterAttribute
{
public bool Disable { get; set; }
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
if (Disable) return;
// Your original logic for your 95% actions goes here.
}
}
Then at your 5% actions just use it like this:
[DataAccessAttribute(Disable=true)]
public ActionResult Index()
{
return View();
}
In AspNetCore, the accepted answer by #darin-dimitrov can be adapted to work as follows:
First, implement IFilterMetadata on the marker attribute:
public class SkipMyGlobalActionFilterAttribute : Attribute, IFilterMetadata
{
}
Then search the Filters property for this attribute on the ActionExecutingContext:
public class MyGlobalActionFilter : IActionFilter
{
public override void OnActionExecuting(ActionExecutingContext context)
{
if (context.Filters.OfType<SkipMyGlobalActionFilterAttribute>().Any())
{
return;
}
// etc
}
}
At least nowadays, this is quite easy: to exclude all action filters from an action, just add the OverrideActionFiltersAttribute.
There are similar attributes for other filters: OverrideAuthenticationAttribute, OverrideAuthorizationAttribute and OverrideExceptionAttribute.
See also https://www.strathweb.com/2013/06/overriding-filters-in-asp-net-web-api-vnext/
Create a custom Filter Provider. Write a class which will implement IFilterProvider. This IFilterProvider interface has a method GetFilters which returns Filters which needs to be executed.
public class MyFilterProvider : IFilterProvider
{
private readonly List<Func<ControllerContext, object>> filterconditions = new List<Func<ControllerContext, object>>();
public void Add(Func<ControllerContext, object> mycondition)
{
filterconditions.Add(mycondition);
}
public IEnumerable<Filter> GetFilters(ControllerContext controllerContext, ActionDescriptor actionDescriptor)
{
return from filtercondition in filterconditions
select filtercondition(controllerContext) into ctrlContext
where ctrlContext!= null
select new Filter(ctrlContext, FilterScope.Global);
}
}
=============================================================================
In Global.asax.cs
public static void RegisterGlobalFilters(GlobalFilterCollection filters)
{
MyFilterProvider provider = new MyFilterProvider();
provider.Add(d => d.RouteData.Values["action"].ToString() != "SkipFilterAction1 " ? new NHibernateActionFilter() : null);
FilterProviders.Providers.Add(provider);
}
protected void Application_Start()
{
RegisterGlobalFilters(GlobalFilters.Filters);
}
Well, I think I got it working for ASP.NET Core.
Here's the code:
public override async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
{
// Prepare the audit
_parameters = context.ActionArguments;
await next();
if (IsExcluded(context))
{
return;
}
var routeData = context.RouteData;
var controllerName = (string)routeData.Values["controller"];
var actionName = (string)routeData.Values["action"];
// Log action data
var auditEntry = new AuditEntry
{
ActionName = actionName,
EntityType = controllerName,
EntityID = GetEntityId(),
PerformedAt = DateTime.Now,
PersonID = context.HttpContext.Session.GetCurrentUser()?.PersonId.ToString()
};
_auditHandler.DbContext.Audits.Add(auditEntry);
await _auditHandler.DbContext.SaveChangesAsync();
}
private bool IsExcluded(ActionContext context)
{
var controllerActionDescriptor = (Microsoft.AspNetCore.Mvc.Controllers.ControllerActionDescriptor)context.ActionDescriptor;
return controllerActionDescriptor.ControllerTypeInfo.IsDefined(typeof(ExcludeFromAuditing), false) ||
controllerActionDescriptor.MethodInfo.IsDefined(typeof(ExcludeFromAuditing), false);
}
The relevant code is in the 'IsExcluded' method.
You can change your filter code like this:
public class NHibernateActionFilter : ActionFilterAttribute
{
public IEnumerable<string> ActionsToSkip { get; set; }
public NHibernateActionFilter(params string[] actionsToSkip)
{
ActionsToSkip = actionsToSkip;
}
public override void OnActionExecuting(ActionExecutingContext filterContext)
{
if (null != ActionsToSkip && ActionsToSkip.Any(a =>
String.Compare(a, filterContext.ActionDescriptor.ActionName, true) == 0))
{
return;
}
//here you code
}
}
And use it:
[NHibernateActionFilter(new[] { "SkipFilterAction1 ", "Action2"})]
I have started an MVC 3 template project in VS10 and modified global.asax.cs as such:
public static void RegisterGlobalFilters(GlobalFilterCollection filters)
{
filters.Add(new HandleErrorAttribute { ExceptionType = typeof(DivideByZeroException), View = "DivideByZeroException", Order = 1 });
filters.Add(new HandleErrorAttribute { View = "AllOtherExceptions", Order = 2 });
}
To web.config I added:
<customErrors mode="On">
Then created the corresponding views and finally added a DivideByZero-throw to one of the actions.
The result: The view AllOtherExceptions is rendered.
Much though I hate to disagree with anything Darin says, he is wrong on this one.
There is no problem with setting the properties (that's the way you are supposed to do it).
The only reason your original code didn't work as expected is because you have the Order set wrong.
See MSDN:
The OnActionExecuting(ActionExecutingContext),
OnResultExecuting(ResultExecutingContext), and
OnAuthorization(AuthorizationContext) filters run in forward order.
The OnActionExecuted(ActionExecutedContext),
OnResultExecuting(ResultExecutingContext), and
OnException(ExceptionContext) filters run in reverse order.
So your generic AllOtherExceptions filter needs to be the lowest Order number, not the highest.
Hopefully that helps for next time.
You shouldn't set properties when registering a global action filter. You could write a custom handle error filter:
public class MyHandleErrorAttribute : FilterAttribute, IExceptionFilter
{
public void OnException(ExceptionContext filterContext)
{
if (!filterContext.IsChildAction && (!filterContext.ExceptionHandled && filterContext.HttpContext.IsCustomErrorEnabled))
{
Exception innerException = filterContext.Exception;
if ((new HttpException(null, innerException).GetHttpCode() == 500))
{
var viewName = "AllOtherExceptions";
if (typeof(DivideByZeroException).IsInstanceOfType(innerException))
{
viewName = "DivideByZeroException";
}
string controllerName = (string)filterContext.RouteData.Values["controller"];
string actionName = (string)filterContext.RouteData.Values["action"];
HandleErrorInfo model = new HandleErrorInfo(filterContext.Exception, controllerName, actionName);
ViewResult result = new ViewResult
{
ViewName = viewName,
ViewData = new ViewDataDictionary<HandleErrorInfo>(model),
TempData = filterContext.Controller.TempData
};
filterContext.Result = result;
filterContext.ExceptionHandled = true;
filterContext.HttpContext.Response.Clear();
filterContext.HttpContext.Response.StatusCode = 500;
filterContext.HttpContext.Response.TrySkipIisCustomErrors = true;
}
}
}
}
and then register it:
public static void RegisterGlobalFilters(GlobalFilterCollection filters)
{
filters.Add(new MyHandleErrorAttribute());
}
Do check fear's answer below. It's certainly the simpler, if it works.
Since it came after a few weeks, this is how my filter finally spelled out, using Darins response and incorporating Elmah-reporting, with code from this topic.
I still don't know why you can't set properties on a global action filter.
public class MyHandleErrorAttribute : FilterAttribute, IExceptionFilter
{
public void OnException(ExceptionContext filterContext)
{
if (!filterContext.IsChildAction &&
(!filterContext.ExceptionHandled && filterContext.HttpContext.IsCustomErrorEnabled))
{
var innerException = filterContext.Exception;
if ((new HttpException(null, innerException).GetHttpCode() == 500))
{
var viewName = "GeneralError";
if (typeof (HttpAntiForgeryException).IsInstanceOfType(innerException))
viewName = "SecurityError";
var controllerName = (string) filterContext.RouteData.Values["controller"];
var actionName = (string) filterContext.RouteData.Values["action"];
var model = new HandleErrorInfo(filterContext.Exception, controllerName, actionName);
var result = new ViewResult
{
ViewName = viewName,
ViewData = new ViewDataDictionary<HandleErrorInfo>(model),
TempData = filterContext.Controller.TempData
};
filterContext.Result = result;
filterContext.ExceptionHandled = true;
filterContext.HttpContext.Response.Clear();
filterContext.HttpContext.Response.StatusCode = 500;
filterContext.HttpContext.Response.TrySkipIisCustomErrors = true;
//From here on down, this is all code for Elmah-reporting.
var version = Assembly.GetExecutingAssembly().GetName().Version;
filterContext.Controller.ViewData["Version"] = version.ToString();
var e = filterContext.Exception;
if (!filterContext.ExceptionHandled // if unhandled, will be logged anyhow
|| RaiseErrorSignal(e) // prefer signaling, if possible
|| IsFiltered(filterContext)) // filtered?
return;
LogException(e);
}
}
}
private static bool RaiseErrorSignal(Exception e)
{
HttpContext context = HttpContext.Current;
if (context == null)
return false;
var signal = ErrorSignal.FromContext(context);
if (signal == null)
return false;
signal.Raise(e, context);
return true;
}
private static bool IsFiltered(ExceptionContext context)
{
var config = context.HttpContext.GetSection("elmah/errorFilter")
as ErrorFilterConfiguration;
if (config == null)
return false;
var testContext = new ErrorFilterModule.AssertionHelperContext(
context.Exception, HttpContext.Current);
return config.Assertion.Test(testContext);
}
private static void LogException(Exception e)
{
HttpContext context = HttpContext.Current;
ErrorLog.GetDefault(context).Log(new Error(e, context));
}
}
I need something that would work like this:
public ActionResult Ac()
{
try {
//stuff...
}
catch(MyException ex)
{
//handle
}
}
but without putting try catch in each action method
You want to annotate your classes with HandleErrorAttribute - http://msdn.microsoft.com/en-us/library/system.web.mvc.handleerrorattribute.aspx.
If the functionality of the built in handler above isn't sufficient then you can define your own class which implements IExceptionFilter - the OnException method takes an ExceptionContext object with Result and HttpContext properties you can use to control the outcome, something like:
public class MyHandleErrorAttribute : FilterAttribute, IExceptionFilter
{
public void OnException(ExceptionContext filterContext)
{
Exception e = filterContext.Exception;
// Do some logging etc. here
if (!filterContext.ExceptionHandled && filterContext.HttpContext.IsCustomErrorEnabled)
{
ViewResult lResult = ...
filterContext.Result = lResult;
filterContext.ExceptionHandled = true;
filterContext.HttpContext.Response.Clear();
filterContext.HttpContext.Response.StatusCode = 500;
filterContext.HttpContext.Response.TrySkipIisCustomErrors = true;
}
}
Use Exception Filters for exception handling.
How about
[HandleError(ExceptionType = typeof(MyException ), View = "MyErrView"))]
public ActionResult Ac()
{
//stuff
}
but with a custom HandleError Attribute that handles the type of exceptions you are targeting. This SO question should give you a good start.