Web API unreliably returning status code and error message object from PUT

Question

I would like to return an HTTP status code & error message from a PUT method of an ApiController.

I have created an error class:

public class ErrorInformation
{
    public string Message { get; set; }
    public DateTime ErrorDate { get; set; }
}

and in the Put method I return this:

return new ResponseMessageResult(Request.CreateResponse(HttpStatusCode.NotModified,
                    new ErrorInformation { Message = "We apologize but an unexpected error occured. Please try again later.", ErrorDate = DateTime.UtcNow }));

When the status code is, say:

HttpStatusCode.OK or HttpStatusCode.InternalServerError - the caller gets the object in the response. But when it is HttpStatusCode.NotModified - only the status code is returned.

Why is this - and how can I ensure both my object and the status code are always returned?

thx.

This is not valid use of "Not Modified" status code anyway, especially with the message like ""We apologize but an unexpected error occured. Please try again later." — Evk, Feb 27 '17 at 17:44

score 4 · Accepted Answer · answered Feb 27 '17 at 17:36

4

According to the HTTP specification, a 304 "not modified" response is not allowed to have a response body:

The 304 response MUST NOT contain a message-body, and thus is always terminated by the first empty line after the header fields.

Source: https://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.3.5

answered Feb 27 '17 at 17:36

crates_barrels

988
13
15

Thanks - I was thinking of using this error code when a PUT has data that fails validation (eg a field is of the wrong type, too short, missing etc). Which code would you recommend for that scenario? (the number available is huge - hard to pin one down). – niico Feb 27 '17 at 18:51
I guess looking here - http://stackoverflow.com/questions/3290182/rest-http-status-codes-for-failed-validation-or-invalid-duplicate - 400 would be best? – niico Feb 27 '17 at 19:04
1

Yes, I believe in your case a 400 "Bad request" is appropriate. Because it's definitely a client error, use a status code in the 4xx range. 3xx codes are mostly for redirection. – crates_barrels Feb 28 '17 at 09:54

score 0 · Answer 2 · answered Feb 27 '17 at 18:45

In addition to the answer by @crates_barrels, I should day that it is definitely looks like Internal Server Error to me. If you have some kind of conflict, then you can use a special Conflict response in here. So I suggest that you check up the status codes and how they are used, e.g. in wiki. Then you can try to apply them in a best way to your scenario.

Web API unreliably returning status code and error message object from PUT

2 Answers2