JsonHttpClient vs JsonServiceClient

Clients
1

I had a number of integration test passing using JsonServiceClient and swapped the client to the JsonHttpClient and a couple failed.

The message coming back was “Specified method is not supported.”

Here’s the tests that failed (failed on the Post):

    IServiceClient GetClient()
    {
        return new JsonHttpClient(ListeningOn);
    }

    [TestMethod]
    public void GetDeviceScan_Test()
    {
        var client = GetClient();
        client.Post(new DeviceScanRequest { DeviceId = 0});

        Thread.Sleep(1000);
        var status = client.Get<DeviceScanStatusResponse>(new DeviceScanStatus() { DeviceId = 0});
        Assert.IsTrue(status.Enable);
        Assert.IsTrue(status.Status.Length > 5);
    }

My DTO’s

[Route("/bacnet/devicescan/{deviceId}",HttpMethods.Post)]
public class DeviceScanRequest : IHasVersion
{
    public int DeviceId { get; set; }
    public int Version { get; set; }
}

public class DeviceScanResponse : IHasResponseStatus
{
    public ResponseStatus ResponseStatus { get; set; }
}

What fixed it was I included the IReturn in the DTO. (Also worked if I used client.Post<DeviceScanResponse>)

[Route("/bacnet/devicescan/{deviceId}",HttpMethods.Post)]
public class DeviceScanRequest : IHasVersion, IReturn<DeviceScanResponse>
{
    public int DeviceId { get; set; }
    public int Version { get; set; }
}

I thought the IReturn types were optional on DTO’s, but looks like it isn’t on the new JsonHttpClient.

2

The Service Clients needs to know what response type to deserialize it into, if you’re not specifying with the IReturn<T> marker than you must specify it on the call-site, e.g:

client.Post<DeviceScanResponse>(new DeviceScanRequest { DeviceId = 0});

If you don’t you’re not calling a IServiceClient API, you’re calling this extension method which returns a .NET WebRequest that the HttpClient doesn’t support.

3

That makes sense. The “drop in” replacement verbiage in the wiki through me for a loop. Thanks.

4

It’s only a drop-in replacement when you stick to the IServiceClient interfaces. This is a concrete convenience extension method only meant for .NET WebRequest clients which is historically maintained for backwards-compatibility before we had multiple implementations since no other HTTP Client implementation can implement it.

I’ll deprecate them as it’s not obvious from the call-site it’s returning a HttpWebResponse that needs to be disposed:

using (var webRes = client.Post(new DeviceScanRequest { DeviceId = 0})) {}

In which it’s better to call it with an explicit Response Type so it’s obvious this returns a HttpWebResponse and needs to be disposed, e.g:

using (client.Post<HttpWebResponse>(new DeviceScanRequest { DeviceId = 0})) {}

To mitigate future issues all .NET WebRequest extension methods that return an implicit HttpWebResponse have now deprecated in this commit in favor of the correct usage above.