I have this
public class ExceptionFilter : IExceptionFilter
{
public void OnException(ExceptionContext context)
{
Exception exception = context.Exception;
if (!(exception is HttpException))
{
Trace.TraceError("ExceptionFilter: " + ExceptionUtilities.GetFullExceptionMessage(exception));
Trace.Flush();
}
}
}
and this in global.asax
public static void RegisterGlobalFilters(GlobalFilterCollection filters)
{
filters.Add(new Filters.ExceptionFilter());
filters.Add(new HandleErrorAttribute());
}
but when I trigger an error by creating a dangerous request like this
example.com/dsfgds:dfgd
I get an exception:
A potentially dangerous Request.Path value was detected from the
client (:)
and the filter doesn't fire and the breakpoint inside doesn't get hit.
That's because you're registering an IExceptionFilter with MVC, and as such it will only capture unhandled exceptions that were raised within an MVC Action (and I think maybe other MVC filters? Don't quote me on that). But the error about a potentially dangerous request is an ASP.NET error, the request never made it to MVC, so the MVC error filter never gets called. Likewise, any IIS level errors would also not be handled by this. For non-MVC errors you still need to monitor the Application_OnError event. Or in the case of exception handlers like Elmah, let it monitor the event for you.
I came across a weird behavior but I am not sure if I am on the right track here.
I have a controller which overrides OnException method of the Controller base class.
public class ControllerFiltersController : Controller {
public ActionResult Index() {
throw new NotImplementedException();
}
protected override void OnException(ExceptionContext filterContext) {
Trace.TraceInformation(
"ControllerFiltersController Exception: " + DateTime.Now.ToString("hh:mm:ss.fff")
);
}
}
I also have an custom ExceptionFilter as follows:
public class HandleErrorCustom : IExceptionFilter {
public void OnException(ExceptionContext filterContext) {
Trace.TraceInformation(
"HandleErrorCustom Exception Message: " + DateTime.Now.ToString("hh:mm:ss.fff")
);
}
}
Then, I registered it as a global filter:
public static void RegisterGlobalFilters(GlobalFilterCollection filters) {
filters.Add(new HandleErrorCustom());
}
What I expected is here for the controller instance filter to run before global filter since the order of filters which are provided by ControllerInstanceFilterProvider is Int32.MinValue and the scope of them is FilterScope.First.
As also explained here: ASP.NET MVC 3 Service Location, Part 4: Filters
But the result is different:
iisexpress.exe Information: 0 : HandleErrorCustom Exception Message:
06:56:49.972
iisexpress.exe Information: 0 : ControllerFiltersController Exception:
06:56:49.974
This is an ASP.NET MVC 4 application and I am not aware of any changes which effects the filter ordering behavior of ASP.NET MVC 3. What am I missing here?
This is expected behavior.
Filter ordering depends on the direction the information is flowing. If the information is flowing into the action, then the order is as you expect it; if the information is flowing back out of the action, then the order is reversed.
For example, assume you have three filters in this order: F1, F2, F3. Assume that these are action filters (meaning, they're listening to ActionExecuting and ActionExecuted). The order the system will run them is as follows:
F1.ActionExecuting()
F2.ActionExecuting()
F3.ActionExecuting()
Action()
F3.ActionExecuted()
F2.ActionExecuted()
F1.ActionExecuted()
Error handlers are, by definition, filters that run on the return-side of actions, so their order is reversed.
Using an API controller in MVC4, when the controller action throws an exception, ELMAH does not log the error.
I think the problem is that MVC4 sets the HTTP status code to 500, and it returns the exception details in a JSON object, but it does not throw an unhandled exception so ELMAH never sees it.
How can I get ELMAH to capture all responses where the status code is not 200?
The anwser described before doesn't work. I've tried on my test server and received an error ("The given filter instance must implement one or more of the following filter interfaces: IAuthorizationFilter, IActionFilter, IResultFilter, IExceptionFilter.")
Then I realized what happened .... you are trying to add the custom filter to the MVC Global Filter (filters.Add(new ElmahHandledErrorLoggerFilter());)
To fix that, I've split the filter registration in GlobalFilter and HttpFilter
FilterConfig.cs
public static void RegisterGlobalFilters(GlobalFilterCollection filters)
{
filters.Add(new HandleErrorAttribute());
}
public static void RegisterHttpFilters(HttpFilterCollection filters)
{
filters.Add(new ElmahHandledErrorLoggerFilter());
}
Global.asax
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
FilterConfig.RegisterHttpFilters(GlobalConfiguration.Configuration.Filters);
;-)
UPDATE: This answer does not work in latest versions. Use julianox's answer.
Answer found from information here: http://www.asp.net/web-api/overview/web-api-routing-and-actions/exception-handling
Where the exception filter logs to elmah:
public class ElmahHandledErrorLoggerFilter : ExceptionFilterAttribute
{
public override void OnException(HttpActionExecutedContext actionExecutedContext)
{
base.OnException(actionExecutedContext);
ErrorSignal.FromCurrentContext().Raise(actionExecutedContext.Exception);
}
}
but you also have to add the error filter to the GlobalConfiguration filters:
public static void RegisterGlobalFilters(GlobalFilterCollection filters)
{
GlobalConfiguration.Configuration.Filters.Add(new ElmahHandledErrorLoggerFilter());
filters.Add(new ElmahHandledErrorLoggerFilter());
filters.Add(new HandleErrorAttribute());
}
First of all, sorry for my bad english.
I have faced a strange problem using asp net mvc.
I have simple controller, which can execute 2 operations. The first operation is continuous and can take a several minutes. And the other is short, and executed some seconds.
Something like this:
public class TestController : Controler {
[HttpPost]
public string Func1(long id) {
// continuous operation
return new ValueGetter().Get(id)
}
[HttpPost]
public string Func2(long id) {
return "Abc";
}
}
And from the client side i call thouse methods via jqueries post:
$.post(url).sucess(...);
The problem consists in the next: while the first operation is executed, the second operation will wait, until first is finished.
I tried to use AsyncController as described there http://msdn.microsoft.com/en-us/library/ee728598.aspx, but the result is the same...
I have logged some application events in global.asax:
protected void Application_PostMapRequestHandler(object sender, EventArgs e) {
LoggerManager.Info("PostMapRequestHandler fired in global.asax");
}
protected void Application_AcquireRequestState(object sender, EventArgs e) {
LoggerManager.Info("AcquireRequestState fired in global.asax");
}
And if I for example, call the first method once, and then Immediately call the second method three times, I have the following result in the log file:
1.PostMapRequestHandler
2.AcquireRequestState
3.PostMapRequestHandler
4.PostMapRequestHandler
5.PostMapRequestHandler
... after first method is executed sucessfuly
6.AcquireRequestState
7.AcquireRequestState
8.AcquireRequestState
I use IIS 7(not express) and asp.net mvc 3
Why it happen and how I can solve it?
I found the answer to my question here:
Session less MVC Controller for MVC 2 / RC (MSDN Blogs)
I hope it will help, if someone faces a similar problem.
I am trying to use ELMAH to log errors in my ASP.NET MVC application, however when I use the [HandleError] attribute on my controllers ELMAH doesn't log any errors when they occur.
As I am guessing its because ELMAH only logs unhandled errors and the [HandleError] attribute is handling the error so thus no need to log it.
How do I modify or how would I go about modifying the attribute so ELMAH can know that there was an error and log it..
Edit: Let me make sure everyone understands, I know I can modify the attribute thats not the question I'm asking... ELMAH gets bypassed when using the handleerror attribute meaning it won't see that there was an error because it was handled already by the attribute... What I am asking is there a way to make ELMAH see the error and log it even though the attribute handled it...I searched around and don't see any methods to call to force it to log the error....
You can subclass HandleErrorAttribute and override its OnException member (no need to copy) so that it logs the exception with ELMAH and only if the base implementation handles it. The minimal amount of code you need is as follows:
using System.Web.Mvc;
using Elmah;
public class HandleErrorAttribute : System.Web.Mvc.HandleErrorAttribute
{
public override void OnException(ExceptionContext context)
{
base.OnException(context);
if (!context.ExceptionHandled)
return;
var httpContext = context.HttpContext.ApplicationInstance.Context;
var signal = ErrorSignal.FromContext(httpContext);
signal.Raise(context.Exception, httpContext);
}
}
The base implementation is invoked first, giving it a chance to mark the exception as being handled. Only then is the exception signaled. The above code is simple and may cause issues if used in an environment where the HttpContext may not be available, such as testing. As a result, you will want code that is that is more defensive (at the cost of being slightly longer):
using System.Web;
using System.Web.Mvc;
using Elmah;
public class HandleErrorAttribute : System.Web.Mvc.HandleErrorAttribute
{
public override void OnException(ExceptionContext context)
{
base.OnException(context);
if (!context.ExceptionHandled // if unhandled, will be logged anyhow
|| TryRaiseErrorSignal(context) // prefer signaling, if possible
|| IsFiltered(context)) // filtered?
return;
LogException(context);
}
private static bool TryRaiseErrorSignal(ExceptionContext context)
{
var httpContext = GetHttpContextImpl(context.HttpContext);
if (httpContext == null)
return false;
var signal = ErrorSignal.FromContext(httpContext);
if (signal == null)
return false;
signal.Raise(context.Exception, httpContext);
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,
GetHttpContextImpl(context.HttpContext));
return config.Assertion.Test(testContext);
}
private static void LogException(ExceptionContext context)
{
var httpContext = GetHttpContextImpl(context.HttpContext);
var error = new Error(context.Exception, httpContext);
ErrorLog.GetDefault(httpContext).Log(error);
}
private static HttpContext GetHttpContextImpl(HttpContextBase context)
{
return context.ApplicationInstance.Context;
}
}
This second version will try to use error signaling from ELMAH first, which involves the fully configured pipeline like logging, mailing, filtering and what have you. Failing that, it attempts to see whether the error should be filtered. If not, the error is simply logged. This implementation does not handle mail notifications. If the exception can be signaled then a mail will be sent if configured to do so.
You may also have to take care that if multiple HandleErrorAttribute instances are in effect then duplicate logging does not occur, but the above two examples should get your started.
Sorry, but I think the accepted answer is an overkill. All you need to do is this:
public class ElmahHandledErrorLoggerFilter : IExceptionFilter
{
public void OnException (ExceptionContext context)
{
// Log only handled exceptions, because all other will be caught by ELMAH anyway.
if (context.ExceptionHandled)
ErrorSignal.FromCurrentContext().Raise(context.Exception);
}
}
and then register it (order is important) in Global.asax.cs:
public static void RegisterGlobalFilters (GlobalFilterCollection filters)
{
filters.Add(new ElmahHandledErrorLoggerFilter());
filters.Add(new HandleErrorAttribute());
}
There is now an ELMAH.MVC package in NuGet that includes an improved solution by Atif and also a controller that handles the elmah interface within MVC routing (no need to use that axd anymore)
The problem with that solution (and with all the ones here) is that one way or another the elmah error handler is actually handling the error, ignoring what you might want to set up as a customError tag or through ErrorHandler or your own error handler
The best solution IMHO is to create a filter that will act at the end of all the other filters and log the events that have been handled already. The elmah module should take care of loging the other errors that are unhandled by the application. This will also allow you to use the health monitor and all the other modules that can be added to asp.net to look at error events
I wrote this looking with reflector at the ErrorHandler inside elmah.mvc
public class ElmahMVCErrorFilter : IExceptionFilter
{
private static ErrorFilterConfiguration _config;
public void OnException(ExceptionContext context)
{
if (context.ExceptionHandled) //The unhandled ones will be picked by the elmah module
{
var e = context.Exception;
var context2 = context.HttpContext.ApplicationInstance.Context;
//TODO: Add additional variables to context.HttpContext.Request.ServerVariables for both handled and unhandled exceptions
if ((context2 == null) || (!_RaiseErrorSignal(e, context2) && !_IsFiltered(e, context2)))
{
_LogException(e, context2);
}
}
}
private static bool _IsFiltered(System.Exception e, System.Web.HttpContext context)
{
if (_config == null)
{
_config = (context.GetSection("elmah/errorFilter") as ErrorFilterConfiguration) ?? new ErrorFilterConfiguration();
}
var context2 = new ErrorFilterModule.AssertionHelperContext((System.Exception)e, context);
return _config.Assertion.Test(context2);
}
private static void _LogException(System.Exception e, System.Web.HttpContext context)
{
ErrorLog.GetDefault((System.Web.HttpContext)context).Log(new Elmah.Error((System.Exception)e, (System.Web.HttpContext)context));
}
private static bool _RaiseErrorSignal(System.Exception e, System.Web.HttpContext context)
{
var signal = ErrorSignal.FromContext((System.Web.HttpContext)context);
if (signal == null)
{
return false;
}
signal.Raise((System.Exception)e, (System.Web.HttpContext)context);
return true;
}
}
Now, in your filter config you want to do something like this:
public static void RegisterGlobalFilters(GlobalFilterCollection filters)
{
//These filters should go at the end of the pipeline, add all error handlers before
filters.Add(new ElmahMVCErrorFilter());
}
Notice that I left a comment there to remind people that if they want to add a global filter that will actually handle the exception it should go BEFORE this last filter, otherwise you run into the case where the unhandled exception will be ignored by the ElmahMVCErrorFilter because it hasn't been handled and it should be loged by the Elmah module but then the next filter marks the exception as handled and the module ignores it, resulting on the exception never making it into elmah.
Now, make sure the appsettings for elmah in your webconfig look something like this:
<add key="elmah.mvc.disableHandler" value="false" /> <!-- This handles elmah controller pages, if disabled elmah pages will not work -->
<add key="elmah.mvc.disableHandleErrorFilter" value="true" /> <!-- This uses the default filter for elmah, set to disabled to use our own -->
<add key="elmah.mvc.requiresAuthentication" value="false" /> <!-- Manages authentication for elmah pages -->
<add key="elmah.mvc.allowedRoles" value="*" /> <!-- Manages authentication for elmah pages -->
<add key="elmah.mvc.route" value="errortracking" /> <!-- Base route for elmah pages -->
The important one here is "elmah.mvc.disableHandleErrorFilter", if this is false it will use the handler inside elmah.mvc that will actually handle the exception by using the default HandleErrorHandler that will ignore your customError settings
This setup allows you to set your own ErrorHandler tags in classes and views, while still loging those errors through the ElmahMVCErrorFilter, adding a customError configuration to your web.config through the elmah module, even writing your own Error Handlers. The only thing you need to do is remember to not add any filters that will actually handle the error before the elmah filter we've written. And I forgot to mention: no duplicates in elmah.
You can take the code above and go one step further by introducing a custom controller factory that injects the HandleErrorWithElmah attribute into every controller.
For more infomation check out my blog series on logging in MVC. The first article covers getting Elmah set up and running for MVC.
There is a link to downloadable code at the end of the article. Hope that helps.
http://dotnetdarren.wordpress.com/
I'm new in ASP.NET MVC. I faced the same problem, the following is my workable in my Erorr.vbhtml (it work if you only need to log the error using Elmah log)
#ModelType System.Web.Mvc.HandleErrorInfo
#Code
ViewData("Title") = "Error"
Dim item As HandleErrorInfo = CType(Model, HandleErrorInfo)
//To log error with Elmah
Elmah.ErrorLog.GetDefault(HttpContext.Current).Log(New Elmah.Error(Model.Exception, HttpContext.Current))
End Code
<h2>
Sorry, an error occurred while processing your request.<br />
#item.ActionName<br />
#item.ControllerName<br />
#item.Exception.Message
</h2>
It is simply!
A completely alternative solution is to not use the MVC HandleErrorAttribute, and instead rely on ASP.Net error handling, which Elmah is designed to work with.
You need to remove the default global HandleErrorAttribute from App_Start\FilterConfig (or Global.asax), and then set up an error page in your Web.config:
<customErrors mode="RemoteOnly" defaultRedirect="~/error/" />
Note, this can be an MVC routed URL, so the above would redirect to the ErrorController.Index action when an error occurs.
For me it was very important to get email logging working. After some time I discover that this need only 2 lines of code more in Atif example.
public class HandleErrorWithElmahAttribute : HandleErrorAttribute
{
static ElmahMVCMailModule error_mail_log = new ElmahMVCMailModule();
public override void OnException(ExceptionContext context)
{
error_mail_log.Init(HttpContext.Current.ApplicationInstance);
[...]
}
[...]
}
I hope this will help someone :)
This is exactly what I needed for my MVC site configuration!
I added a little modification to the OnException method to handle multiple HandleErrorAttribute instances, as suggested by Atif Aziz:
bear in mind that you may have to take care that if multiple HandleErrorAttribute instances are in effect then duplicate logging does not occur.
I simply check context.ExceptionHandled before invoking the base class, just to know if someone else handled the exception before current handler.
It works for me and I post the code in case someone else needs it and to ask if anyone knows if I overlooked anything.
Hope it is useful:
public override void OnException(ExceptionContext context)
{
bool exceptionHandledByPreviousHandler = context.ExceptionHandled;
base.OnException(context);
Exception e = context.Exception;
if (exceptionHandledByPreviousHandler
|| !context.ExceptionHandled // if unhandled, will be logged anyhow
|| RaiseErrorSignal(e) // prefer signaling, if possible
|| IsFiltered(context)) // filtered?
return;
LogException(e);
}