Using ELMAH in a console application

Question

I just started using ELMAH and am a fan. My team supports a large number of web applications and I'm particularly excited that ELMAH lets us save exceptions from each application to the same MS SQL database table.

We also support a few console, DLL and desktop applications. Is it possible to use the ELMAH DLL to log exceptions in these apps to that same location?

Answer 1

We needed the ability to log from a console app and a windows service in addition to our ASP.NET site. I used the answer (ErrorLog.GetDefault(null);) which worked well until I needed to email too.

So, here is my solution. It handles the log, email, tweet and filtering (both in the config file and in code). I have also wrapped the main call as an extension to Exception so it can be called like: catch(Exception ex) { ex.LogToElmah(); }

To filter in code, hook the corresponding .Filtering event: ElmahExtension.ErrorLog.Filtering += new ExceptionFilterEventHandler(ErrorLog_Filtering);

Code:

using System; using System.Web; using Elmah; namespace System {     public static class ElmahExtension     {         public static void LogToElmah(this Exception ex)         {             if (HttpContext.Current != null)             {                 ErrorSignal.FromCurrentContext().Raise(ex);             }             else             {                 if (httpApplication == null) InitNoContext();                 ErrorSignal.Get(httpApplication).Raise(ex);             }         }              private static HttpApplication httpApplication = null;             private static ErrorFilterConsole errorFilter = new ErrorFilterConsole();              public static ErrorMailModule ErrorEmail = new ErrorMailModule();             public static ErrorLogModule ErrorLog = new ErrorLogModule();             public static ErrorTweetModule ErrorTweet = new ErrorTweetModule();              private static void InitNoContext()             {                 httpApplication = new HttpApplication();                 errorFilter.Init(httpApplication);                  (ErrorEmail as IHttpModule).Init(httpApplication);                 errorFilter.HookFiltering(ErrorEmail);                  (ErrorLog as IHttpModule).Init(httpApplication);                 errorFilter.HookFiltering(ErrorLog);                                  (ErrorTweet as IHttpModule).Init(httpApplication);                 errorFilter.HookFiltering(ErrorTweet);             }              private class ErrorFilterConsole : ErrorFilterModule             {                 public void HookFiltering(IExceptionFiltering module)                 {                     module.Filtering += new ExceptionFilterEventHandler(base.OnErrorModuleFiltering);                 }             }     } } 

In addition, you will need to add a reference to the System.Web.dll in your project for this to work.

EDIT: As per the comments, this code will send emails only if your config file has <errorMail async="false"/>. Refer to this code snippet should you want to keep <errorMail async="true"/> in your config file (to be used when HttpContext.Current is available).