How to convert JSON to C# classes?

Question

I have a complex JSON object that I want represent as C# class. I have a head start on the parent class called "Form", but how can I represent a collection for different types (see the "elements" object below)?

Here is the JSON object:

{
    "action": "index.html",
    "method": "post",
    "elements":
[
{
    "type": "fieldset",
    "caption": "User information",
    "elements":
    [
        {
            "name": "email",
            "caption": "Email address",
            "type": "text",
            "placeholder": "E.g. [email protected]",
            "validate":
            {
                "email": true
            }
        },
        {
            "name": "password",
            "caption": "Password",
            "type": "password",
            "id": "registration-password",
            "validate":
            {
                "required": true,
                "minlength": 5,
                "messages":
                {
                    "required": "Please enter a password",
                    "minlength": "At least {0} characters long"
                }
            }
        },
        {
            "name": "password-repeat",
            "caption": "Repeat password",
            "type": "password",
            "validate":
            {
                "equalTo": "#registration-password",
                "messages":
                {
                    "equalTo": "Please repeat your password"
                }
            }
        },
        {
            "type": "radiobuttons",
            "caption": "Sex",
            "name": "sex",
            "class": "labellist",
            "options":
            {
                "f": "Female",
                "m": "Male"
            }
        }
    ]
]
}

The class I have start looks like this:

public class Form
{
    public Guid id
    {
        get;
        set;
    }

    public string action
    {
        get;
        set;
    }

    public string method
    {
        get;
        set;
    }

    public ??? elements
    {
        get;
        set;
    }

    public Form()
    {

    }
}

How do I handle the "elements" property to get the desired JSON output?

I am using WCF 4.0 with these atributes in the web.config: automaticFormatSelectionEnabled="false", defaultOutgoingResponseFormat="Json". Any help or ideas would be greatly appreciated.

Answer 1

Wow. Fascinating question. Maybe use ExpandoObject / dynamic?

http://msdn.microsoft.com/en-us/library/system.dynamic.expandoobject.aspx

http://blogs.msdn.com/b/csharpfaq/archive/2009/10/01/dynamic-in-c-4-0-introducing-the-expandoobject.aspx?PageIndex=4

Or anonymous types I think are serializable with the built-in .NET JSON serializer.

Answer 2

If you don't have the liberty of using dynamic types from .NET 4 or would like to leverage the benefits that static typing provide, the JSON Class Generator project on codeplex will generate c# classes given a json input string. (shameless plug) I've also taken code from this project and slapped a web UI on it.