Web API error response Id - asp.net-web-api

Question

I have an error response model in my API project:
public class ErrorResponse
{
public string ErrorId { get; set;}
public string Message {get; set;}
}
I need to generate a random ErrorId. I saw the use of Random class but just wondering what is the best way to do this. Some consideration, do I need to create the ErrorId in the constructor of ErrorResponse class and make ErrorId as read-only (no setter) or do I let the ErrorId set by the calling class.

Answer 1

You can create a new Guid and assign it to ErrorId in the constructor:
public ErrorResponse()
{
ErrorId = Guid.NewGuid().ToString();
}
Alternatively, you may want to give the client an http response and include the ErrorId:
return Content(HttpStatusCode.BadRequest, "ErrorId");

Answer 2

You can use the Random class or generate a Guid. But I just want to expand on what I think you are trying to do. Instead of your own custom error response - perhaps considering using the HttpResponseException or the HttpResponseMesssage. You can include a custom / random error identifier in Content / reason or in the message.
public IEnumerable<string> Get()
{
try
{
SomeMethod();
return new string[] { "xxx", "yyy" };
}
catch (Exception e)
{
throw new HttpResponseException(new HttpResponseMessage(HttpStatusCode.InternalServerError)
{
Content = new StringContent("An error occurred."),
ReasonPhrase = "your custom error id"
});
// log
}
}
And:
public HttpResponseMessage Get(int id)
{
try
{
// your code
}
catch (Exception ex)
{
// Log exception code goes here
return Request.CreateErrorResponse(HttpStatusCode.InternalServerError, "your custom error id.”);
}
}

Answer 3

Best way to create Random number is to use Random class in C#... Here is the example
Random rnd = new Random();
int first = rnd.Next(1, 40); //Number between 1(inclusive) and 40(exclusive)
int second = rnd.Next(10); //Number between 0 and 9
Note: If you are going to create more than one random numbers then you should use the same instance of the Random class. If you create new instance too close in time, there are chances that they both will produce the same random numbers as Random class is based(seeded)on System clock.

Answer 4

I use Random but quite not sure if there are consequences in an API application(due to thread-safety, etc). So in the constructor, I generate the ErrorId.
public ErrorResponse()
{
var random = new Random();
const string chars = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz1234567890.!+-?";
ErrorId = new string(Enumerable.Repeat(chars, 10)
.Select(s => s[random.Next(s.Length)]).ToArray());
}