unhandled-exception-handler

An exception catcher for .Net MVC 4 and 5.

Seting up the Unhandled Error Handler in an MVC solution

In your solution's front-end or site project (often called MyProject.Site or MyProject.Web), install the Ui package:

Install-Package Spk.UnhandledExceptionHandlerUi

This will also install Spk.UnhandledExceptionHandlerCore as a dependancy.

Be cautious when accepting (or not) NuGet's requests to overwrite files. If your project or solution is brand new, you can probably accept to overwrite the FilterConfig.cs file.

If not installed, you will need to install NLog:

Install-Package NLog

Wire the handler to your HttpApplication

Open Global.asax.cs. Add a new function that will be used as a catch all error handler:

private void OnUnhandledError(object sender, EventArgs e)
{
    try
    {
        AppErrorUtils.OnApplicationError(sender, e, Server.GetLastError());
    }
    catch (Exception exception)
    {
        LoggingUtils.LogAllExceptions(exception);
    }
}

Then add it to your application's list of error handlers. This can be done from the constructor:

public class Application : System.Web.HttpApplication
{
    public Application()
    {
        Error += OnUnhandledError;
    }

    /* ... */
}

Global filter configuration

This library also comes with a filter that helps managing situations where NotFoundExceptions are thrown (which is different from a controller smoothly returning a 404 response). If your project already had a FilterConfig.cs, and you asked the installer not to overwrite it, then the library's HttpNotFoundFilter must be manually added like this:

public class FilterConfig
{
    public static void RegisterGlobalFilters(GlobalFilterCollection filters)
    {
        filters.Add(new HttpNotFoundFilter { Order = 1 });
    }
}

You should then make sure the filters are loaded when your application starts.

Here's an example for a basic MVC application:

public class Application : System.Web.HttpApplication
{
    /* ... */

    protected void Application_Start()
    {
        FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
    }
}

Here's another example for an Umbraco application:

public class Application : Umbraco.Web.UmbracoApplication
{
    /* ... */

    protected override void OnApplicationStarted(object sender, EventArgs e)
    {
        base.OnApplicationStarted(sender, e);
        FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
    }
}