aknuds1 aknuds1 - 6 months ago 75
JSON Question

How can I return camelCase JSON serialized by JSON.NET from ASP.NET MVC controller methods?

My problem is that I wish to return camelCased (as opposed to the standard PascalCase) JSON data via ActionResults from ASP.NET MVC controller methods, serialized by JSON.NET.

As an example consider the following C# class:

public class Person
{
public string FirstName { get; set; }
public string LastName { get; set; }
}


By default, when returning an instance of this class from an MVC controller as JSON, it'll be serialized in the following fashion:

{
"FirstName": "Joe",
"LastName": "Public"
}


I would like it to be serialized (by JSON.NET) as:

{
"firstName": "Joe",
"lastName": "Public"
}


How do I do this?

Answer

I found an excellent solution to this problem on Mats Karlsson's blog. The solution is to write a subclass of ActionResult that serializes data via JSON.NET, configuring the latter to follow the camelCase convention:

public class JsonCamelCaseResult : ActionResult
{
    public JsonCamelCaseResult(object data, JsonRequestBehavior jsonRequestBehavior)
    {
        Data = data;
        JsonRequestBehavior = jsonRequestBehavior;
    }

    public Encoding ContentEncoding { get; set; }

    public string ContentType { get; set; }

    public object Data { get; set; }

    public JsonRequestBehavior JsonRequestBehavior { get; set; }

    public override void ExecuteResult(ControllerContext context)
    {
        if (context == null)
        {
            throw new ArgumentNullException("context");
        }
        if (JsonRequestBehavior == JsonRequestBehavior.DenyGet && String.Equals(context.HttpContext.Request.HttpMethod, "GET", StringComparison.OrdinalIgnoreCase))
        {
            throw new InvalidOperationException("This request has been blocked because sensitive information could be disclosed to third party web sites when this is used in a GET request. To allow GET requests, set JsonRequestBehavior to AllowGet.");
        }

        var response = context.HttpContext.Response;

        response.ContentType = !String.IsNullOrEmpty(ContentType) ? ContentType : "application/json";
        if (ContentEncoding != null)
        {
            response.ContentEncoding = ContentEncoding;
        }
        if (Data == null)
            return;

        var jsonSerializerSettings = new JsonSerializerSettings
        {
            ContractResolver = new CamelCasePropertyNamesContractResolver()
        };
        response.Write(JsonConvert.SerializeObject(Data, jsonSerializerSettings));
    }
}

Then use this class as follows in your MVC controller method:

public ActionResult GetPerson()
{
    return new JsonCamelCaseResult(new Person { FirstName = "Joe", LastName = "Public" }, JsonRequestBehavior.AllowGet)};
}
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