How do I return an HTTP 400 - Bad Request error from a web form request?

Question

The subject pretty much says it all. I have an EstateReport web form that must be called with an EstateId request parameter. I want to return an appropriate HTTP error if this parameter is not present. How do I return an HTTP error 400 as my response?

On a tangent, should I return an error if the required parameter isn't present, which I feel is more correct, or redirect to the search page for the report, which is more user friendly?

Answer 1

you can:

throw new HttpException(400, "Bad Request");

or

Response.StatusCode = 400;
Response.End();

but I'm with the same thinking as kd7 below - why not display an error message to the client letting them know what is wrong?

Answer 2

So from what I understand the form requires a parameter to display results in a meaningful way. A 400 is a Bad Request, while I understand your thinking, the specification states:

The request could not be understood by the server due to malformed syntax. The client SHOULD NOT repeat the request without modifications.

In its purest sense, if someone requests, say, "EstateReport.aspx" without a parameter, the server can still interpret this and reply with an appropriate response, so it's not a "bad request" in its broadest sense.

What I would suggest is you detect the absence of the parameter and render an appropriate error message with a link to a page where they could select an appropriate "estateId" via some way, so when EstateReport is requested, the parameter is present.