ValueResultConverter.cs

// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System.Net;
using System.Net.Http;

namespace System.Web.Http.Controllers
{
    /// <summary>
    /// A converter for creating responses from actions that return an arbitrary T value.
    /// </summary>
    /// <typeparam name="T">The declared return type of an action.</typeparam>
    public class ValueResultConverter<T> : IActionResultConverter
    {
        public HttpResponseMessage Convert(HttpControllerContext controllerContext, object actionResult)
        {
            if (controllerContext == null)
            {
                throw Error.ArgumentNull("controllerContext");
            }

            HttpResponseMessage resultAsResponse = actionResult as HttpResponseMessage;
            if (resultAsResponse != null)
            {
                resultAsResponse.EnsureResponseHasRequest(controllerContext.Request);
                return resultAsResponse;
            }

            T value = (T)actionResult;
            return controllerContext.Request.CreateResponse<T>(HttpStatusCode.OK, value, controllerContext.Configuration);
        }
    }
}