Json.Net attribute to ignore all properties

Question

Is there an attribute to tell json.net to ignore all properties of a class but include all fields (regardless of access modifiers) ?

If not is there a way to create one ?

Basically I want one attribute decorating the class that will have the equivalent effect to putting [JsonIgnore] infront of each property.

Answer 1

You can add [JsonObject(MemberSerialization.OptIn)] attribute to your class, then everything will be ignored unless you explicitly Opt-In by using a [JsonProperty] attribute on the members.

[JsonObject(MemberSerialization.OptIn)]
public class Address
{
    [JsonProperty]
    private string _field1 = "bob";

    public string Line1 { get; set; }

    public string Line2 { get; set; }

    public string Line3 { get; set; }
}

For example

using System;
using AutoFixture;
using Newtonsoft.Json;

public class Program
{
    public static void Main()
    {
        var fixture = new Fixture();
        var address = fixture.Create<Address>(); // Create an address filled with junk

        var json = JsonConvert.SerializeObject(address);

        Console.WriteLine(json);
    }
}

Will output:

{"_field1":"bob"}