Using Enterprise Library for Web Api MVC4 project

Question

Hi, We are using MVC4 Web Api controllers and also have Enterprise Library 5.0 for exception handling and logging. Since Web api will throw HTTP messages, I am not able to perform exception handling. Can you please suggest on how to handle and log exceptions using EL for MVC4 Web Api projects.

Thanks,

Pugal

Answer 1

Hi Pugal, how you doing?

   To address this issue you should create a Custom Error Handler Class. It´s often something like the example below:

namespace MvcApplication2.Common
{
    public class EntLibErrorHandler : System.Web.Mvc.HandleErrorAttribute
    {
        public override void OnException(System.Web.Mvc.ExceptionContext filterContext)
        {
            //Use Exception Handling App Block here
        }
    }   
}

 After that you should register this Class as a filter in your application. In order to do that, go to AppStart folder and look for FilterConfig class.

There your code shold like this:

namespace MvcApplication2
{
    public class FilterConfig
    {
        public static void RegisterGlobalFilters(GlobalFilterCollection filters)
        {
            filters.Add(new HandleErrorAttribute());

            //Your custom Error Handler
            filters.Add(new Common.EntLibErrorHandler());
        }
    }
}

And that´s all. Every unhandled exception in your application will be handled by your class.

I guess you are not having issues dealing with ent. lib, if so let me know, ok?

Regards

  

Answer 2

Thanks Rafael.

Will this work with Enterprise Library 5.0 or do I need a higher version?

Answer 3

Hi Pugal,

    It will work with ent.lib 5.0. You don´t need to upgrade the version!

Regards.

Answer 4

Thanks Rafael. My exception handling code is like below

ExceptionPolicy.HandleException(ex, "Policy1");

The first parameter is of type "Exception" in above line of code whereas the method specified by you provide only System.Web.Mvc.ExceptionContext. How do I use exception handling here?

Thanks,

Pugal

---

Thanks, Pugazhendhi B

Answer 5

Hi Pugal, 

   The System.Web.Mvc.ExceptionContext class provides a property, called Exception,  with the type you are looking for. 

    So, your code will look like this: 

  public class EntLibErrorHandler : System.Web.Mvc.HandleErrorAttribute
    {
        public override void OnException(System.Web.Mvc.ExceptionContext filterContext)
        {
            ExceptionPolicy.HandleException(filterContext.Exception, "Policy1")
        }
    }

   Regards.

Rafael - http://rafatolotti.wordpress.com/