Handling responses of different types based on status code

[jonnii]

Hi,

I have an end point that creates resources and on success it will
return an object with the new ID and other data, while on failure it
will return a list of validation messages. My RestSharp code looks
like the examples, but I end up having to do something like this:

var response = RestClient.Execute<T>(request);

if(response.StatusCode == HttpStatusCode.BadRequest)
{
var errors =
JsonConvert.DeserializeObject<List<ValidationError>>(response.Content);
.. do something with errors ..
}

In my opinion there's a few things wrong with this, but the biggest is
that I'm explicitly deserializing the content as json (when it could
very well be xml).

I'm wondering what the best way to handle this is?

I can think of a few ways rest sharp could be extended to support this
scenario, for example:

response.DeserializeAs<List<ValidationError>>();

Thoughts?

- jonnii

[jonnii]

It looks like another alternative is to do something like this:

var response = RestClient.Execute(request);

if(response.StatusCode == HttpStatusCode.BadRequest)
{
var validationErrorResponse = (RestResponse<List<ValidationError>>)
response;
... do something ...
}

var expectedResponse = (RestResponse<Something>) response;
return expectedResponse.Data;

This took me a while to find, because the cast to RestResponse<T> is
explicit, but thankfully there's a way to get the right response type
out using the content-types.

[jonnii]

Actually, I spoke to soon, that doesn't work.

[Cristovão Morgado]

I Usually do this:

 client.ExecuteAsync(rq, (response, async) =>
                    {
                        Debug.WriteLine(response.Content);
                        if (response.StatusCode == HttpStatusCode.OK)
                        {
                            if (Register)
                            {
                                var result = JsonConvert.DeserializeObject<Model.PushRegistrationResponse>(response.Content);
                                success(result.Registered);
                            }
                            else
                            {
                                var result = JsonConvert.DeserializeObject<Model.PushUnRegistrationResponse>(response.Content);
                                success(result.Unregistered);
                            }
                        
                        }
                        else
                        {

   var result = JsonConvert.DeserializeObject<Model.PushRegistrationResponseERROR>(response.Content);



                            failure(result);
                        }
                    });

--
Cristovao Morgado
@TheSaintr

[Andy Cutright]

@jonnii There's a hook to support deserializing objects of different types. You can determine the respons status code & change what type should be deseralized. I've not worked with this yet, I just ran into the same sort of problem, and am trying to work it out (as a side line). 

http://restsharp.org/?s=onBeforeDeserialization

Frankly, I don't see why the library doesn't accept a dictionary mapping status codes to deserialization types. 

@cristavo, how's the performance of the JsonConvertDeserializeObject? 

Cheers,

Andy 

[Cristovão Morgado]

JsonConvertDeserializeObject  ... is already used by RestSharp :) being part of JSON.NET ;)

--
Cristovao Morgado
@TheSaintr

[Andy Cutright]

Thanks Cristavão :) 

[jonnii]

I really want the API to look like this:

var client = new RestClient("http://localhost:10013/api");

var person = new Person("abcd");

var request = client
.CreateRequest("people/{id}", new { id = person.Id })
.Content(person);

var response = client.Post(request);

response.On(HttpStatusCode.BadRequest, (ValidationErrors e) =>
{
throw new Exception("omg validation errors");
});

var summary =
response.On(HttpStatusCode.Created).UnWrap<PersonSummary>();

@Cristovão: Your example requires the response to be json, what if
it's xml?

On Mar 22, 11:42 am, Andy Cutright <r.d.c0...@gmail.com> wrote:
> Thanks Cristavão :)
>
> On Thu, Mar 22, 2012 at 8:38 AM, Cristovão Morgado <
>
>
>
>
>
>
>
> cristovao.morg...@gmail.com> wrote:
> > JsonConvertDeserializeObject  ... is already used by RestSharp :) being
> > part of JSON.NET ;)
>

[Cristovão Morgado]

Just change the deserializer...

the "secret" is to use the response.content  (it's a string) and deserialize it as whatever you want...

--
Cristovao Morgado
@TheSaintr

[jonnii]

I understand that, but it's a shame I can't ask restsharp to
deserialize the content for me once I know what the type is, it means
I have to go out to json.net myself and/or switch on the content-type.

On Mar 22, 1:34 pm, Cristovão Morgado <cristovao.morg...@gmail.com>
wrote:

[Cristovão Morgado]

JSON.NET is already bundled with RestSharp...

--
Cristovao Morgado
@TheSaintr

[jonnii]

I know, but it's still not ideal. Why do I have to know the response
is json?

On Mar 22, 1:39 pm, Cristovão Morgado <cristovao.morg...@gmail.com>

[John Sheehan]

I agree this is not ideal, if someone wants to implement this, I'm happy to discuss getting it merged in. It needs to be 100% backwards compatible though.

Something like

client.Execute....<T>(200, response = > { ... } );

Fill in the dots with something descriptive. I can't think of anything at the moment.