Handling expected errors and create response for Web API

Question

I am building a REST API using .net WEB API.

What is the best/recommended response for expected errors?

Situation: There is plane with places.The place can be booked by another person. If reservation was failed by expected error, what the response I need to create ? Now, I use this:

[Route("{number}/reservation"), HttpPost]
public IHttpActionResult Reservation(string number)
{           
  if (string.IsNullOrEmpty(number))
    return Content(HttpStatusCode.BadRequest, "Number required");

  var result = Reservation(number);
  if (result.IsValid)
  {
     return Request.CreateResponse(HttpStatusCode.OK);
  }
  else
     return Request.CreateResponse(HttpStatusCode.OK,result.ErrorMessage);
}

Take a look at https://stackoverflow.com/questions/10732644/best-practice-to-return-errors-in-asp-net-web-api — Abbas Amiri, Oct 25 '17 at 09:23

Ipsit Gaur · Answer 1 · 2017-10-25T09:38:20.927

The way you are generating error responses from your API seems fine, but best practice would bring in using ExceptionFilters in your application which helps you globally handle both(Handled & Unhandled) exceptions.

You can simply create an ExceptionFilter in your application like this -

public class MyExceptionFilterAttribute : ExceptionFilterAttribute 
    {
        public override void OnException(HttpActionExecutedContext context)
        {
            if (context.Exception is NotImplementedException)
            {
                context.Response = new HttpResponseMessage(HttpStatusCode.NotImplemented);
            }
            // Other checks can be added
        }
    }

And then registering your filter in your API in the

WebApiConfig.cs

public static class WebApiConfig
{
    public static void Register(HttpConfiguration config)
    {
        config.Filters.Add(new MyExceptionFilterAttribute());
    }
}

Through this, anytime unhandled Exception will be thrown from your API filter will generate the response using OnException method of the Filter.

Handling expected errors and create response for Web API

1 Answers1