WebApi RaygunWebApiActionFilter usage

In my API controller I want to be able to return a HttpResponseMessage with a HttpStatusCode of BadRequest. Along with this bad request I would also like to add set of custom data to the exception created explaining the bad request. This seems reasonable but as soon as I return the HttpResponseMessage the action filter picks up the OnActionExecuted and because there is not a exception on the HttpActionExecutedContext there a new RaygunWebApiHttpException created to which I have no chance to add the custom data to it.

It seems that if the HttpActionExecutedContext had an exception on it then the OnActionExecuted would just ignore the error and throw it up to the ExceptionLogger.

I am confused on how to proceed can someone provide an example please.

Thanks DD

Hi Jason

Thanks for the reply. Here is the issue that I have with that solution.
When I create the HttpresponseMessage or the HttpResponseException in the controller action I am attaching the data that I would like to add as a typed exception and setting the status code to BadRequest.
The issue that arises when the action filter kicks in and a new RaygunWebApiHttpException is thrown. This new error has now lost the custom data that was added to the response. Then when the sending message event handler fires the message that is being passed is the RaygunWebApiHttpException which does not have the data and thus I do not have access to the original data to add to the raygun message.

Is there someway that I can get that original data through the action filter so that it is not scrubbed?

Thanks DD

I have some context information in the ASP.Net Http Session that I add to customdata for the regular MVC/WebForms Raygun error sending. I'm trying to do the same for WebApi but I hit a wall.

I was able to use the RaygunWebApiClient.Attach to set the User context for the error and I have access to HttpContext.Current there. However, I cannot set "Custom Data" there. Alternatively if I hook up the SendingMessage event I can set "Custom Data" there but for WebApi HttpContext.Current is null there so I cannot get at my session data!

Any ideas?

Hi Alec,

If you add an event handler to the SendingMessage event on RaygunWebApiClient, you can set e.Message.Details.UserCustomData to the custom data you want to send. While you're there you could also set the Tags as well if you want.

Hope that helps.

Cheers, Jamie

Hi Jaime. Yes, I mentioned that SendingMessage event but I don't have access to HttpContext.Current there so can't get at the session data I want to add to custom data.

Sorry, you did mention that! Will teach me for not re-reading the question after mucking around in the code.

One thing you could do is use a lambda expression for the SendingMessage event handler

RaygunWebApiClient.Attach(config, requestMessage => {
   var client = new RaygunWebApiClient();
   client.SendingMessage += (sender, args) =>
   {
     // do your magic here, requestMessage is available.
   };
   return client;
}

That way the SendingMessage handler forms a closure over the requestMessage variable so you'll have access to it.

Hmm. Closer but not quite though I wonder if I'm running into a .NET limitation now...

For reference I have this in Global.asax

protected void Application_PostAuthorizeRequest()
{
  HttpContext.Current.SetSessionStateBehavior(SessionStateBehavior.ReadOnly);
}

The session is null when inside of the lamba. I did a POC showing how I can pull data from it outside the lambda and just tossed the SessionID in the version for reference but it goes to null inside.

RaygunWebApiClient.Attach(configuration, requestMessage => { var client = new RaygunWebApiClient();

            // just an example to show session info is available here
            client.ApplicationVersion = HttpContext.Current.Session.SessionID;

            client.SendingMessage += (sender, args) =>
            {
                // HttpContet.Current is null here. Let's try the one stored in the requestMessage.
                var httpContext = requestMessage.Properties["MS_HttpContext"] as HttpContextBase;

                args.Message.Details.UserCustomData = new Dictionary<string, string>();

                if (httpContext == null)
                    args.Message.Details.UserCustomData.Add("HttpContext", "NOT Available");
                else if (httpContext.Session == null)
                    args.Message.Details.UserCustomData.Add("HttpContext", "NO Session"); // This is what I get here
                else
                    args.Message.Details.UserCustomData.Add("HttpContext", httpContext.Session.SessionID);

            };
            return client;
        });

That will be because we send exceptions on a background thread - https://github.com/MindscapeHQ/raygun4net/blob/master/Mindscape.Raygun4Net.WebApi/RaygunWebApiClient.cs#L395 That is why the HttpContext is null in your original message (I'd forgotten about this aspect).

I think you might need to extract the necessary information from the session outside the SendingMessage handler.

Can you give me an example of passing a simple string variable for example through the closure? I can't seem to get it going without a syntax error.

RaygunWebApiClient.Attach(config, requestMessage => {
   var client = new RaygunWebApiClient();
   string sessionID = HttpContext.Current.Session.SessionID;
   client.SendingMessage += (sender, args) =>
   {
     args.Message.Details.UserCustomData.Add("HttpContext", sessionID);
   };
   return client;
});

You can use any variables from the outer scope as you normally would.

Ah. It works. I had tried that with a different lamba and I think I had just setup the previous closure incorrectly and couldn't access variables outside. This works great.

Here's the kicker. When reading a variable saved in the outer area from the session, the session stored in the message properties is now no longer null either so

args.Message.Details.UserCustomData.Add("HttpContext", httpContext.Session.SessionID);

works too! I tried it twice switching the code back and forth to make sure I wasn't seeing things. I wonder if the runtime is playing some tricks to also marshal the session data over or somehow not using a separate thread and running on the same one. In any case it works.

Thanks for your help!

Using the HttpContext inside the lambda is a bit dodgy, as the HttpContext gets disposed when the request thread cleans up. This may or may not happen before the background send thread is finished (yay multithreading issues). That is why I suggested grabbing the data you need in the setup code(which runs on the request thread), and just using it in the event handler (which runs on the background thread).

Thanks Jamie for the example, really useful! :-)