Responses and Errors

Responses and Errors

Every Restling operation returns RestRequestResult or RestRequestResult<T>. The typed result inherits all untyped metadata and adds Data.

Result properties

Property	Description
IsSuccessful	Whether no exception occurred and the HTTP status is recognized as successful.
StatusCode	Nullable HTTP status code. It can be null when no response was received.
Data	Deserialized value on RestRequestResult<T>.
Content	Response content represented as a string. Binary data is represented as Base64.
RawContent	Original response body bytes.
RetrievedContent	Decoded content, binary flag, and parsed media type.
ContentType	Response media type.
CharSet	Parsed response charset.
Elapsed	Request execution duration.
ResponseHeaders	Read-only response headers and redirect location.
Exception	Execution or decoding exception captured by Restling.
Request	The RestRequest associated with the result.

Standard handling pattern

RestRequestResult<Customer> result = await client.GetAsync<Customer>(uri,
                                                                     cancellationToken: cancellationToken);

if (!result.IsSuccessful)
{
    logger.LogWarning("Request failed with status {StatusCode}: {Error}",
                      result.StatusCode,
                      result.Exception?.Message);
    return;
}

if (result.Data is null)
{
    logger.LogWarning("The response was successful but contained no customer data.");
    return;
}

Customer customer = result.Data;

Do not assume that StatusCode or Data is present. Network failures can produce an exception without an HTTP status, and a successful response may have no body.

Successful status codes

IsSuccessful currently recognizes these values:

• 200 OK
• 201 Created
• 202 Accepted
• 203 Non-Authoritative Information
• 204 No Content
• 205 Reset Content
• 206 Partial Content
• 207 Multi-Status
• 208 Already Reported
• 226 IM Used

Other status codes return IsSuccessful == false, even when the server's semantics treat them specially.

Headers and redirects

IEnumerable<string>? values;

if (result.ResponseHeaders.Headers.TryGetValue("ETag", out values))
{
    Console.WriteLine(string.Join(", ", values));
}

Console.WriteLine(result.ResponseHeaders.RedirectLocation);

The default SocketsHttpHandler disables automatic redirects, allowing the caller to inspect RedirectLocation. You can enable redirects through Client Configuration.

Cancellation

Pass a CancellationToken to every async call. Treat cancellation distinctly when your application needs separate user feedback; inspect Exception for the captured cancellation error.