Get back Request Body within ActionFilter

Question

For logging purposes, I am trying to monitor the requests being made through a WebAPI. I have created and I am looking for a way to get back the body sent through in a request after the request has been fulfilled and responded to. I am trying to do this through using a ActionFilter but thus far have failed in reading the body from the request.

Can anybody give some advice how I may access this information?

For context I am trying to do this within this code:

    public class LoggingActionFilter : ActionFilterAttribute
    {
        public override Task OnActionExecutedAsync(HttpActionExecutedContext actionExecutedContext, CancellationToken cancellationToken)
        {
            var test = actionExecutedContext.Request.Content.ReadAsStringAsync().Result;

            return base.OnActionExecutedAsync(actionExecutedContext, cancellationToken);
        }
    }

I have tried reading back the Content on the actionExecutedContext variable in order to get back the body but have found this to return just blank so far.

Answer 1

you're just dealing with request body so don't need to use OnActionExecutedAsync method, you can just override OnActionExecuting like this,

public override void OnActionExecuting(HttpActionContext actionContext)

   {
       var test = (actionContext.Request.Content as ObjectContent).Value.ToString();
       // your logging code here
   }

Another option available in WebAPI is DelegatingHandler. if you want to log just request body then override SendAsync method,

public class ApiLogHandler : DelegatingHandler
{
 protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request,          
                                               CancellationToken cancellationToken)
 {
   var requestBody = request.Content.ReadAsStringAsync().Result;
   // your logging code here
   return base.SendAsync(request, cancellationToken);
 }
}

If you decided to choose DelegatingHandler then you need to register that handler to Global message handlers.