Alternative way to specify Json.net metadata without annotations?

Question

In Json.NET, how do I specify metadata, eg what properties to serialize, on classes not under my control, such as entity framework classes?

I could swear I've already read about a way, but I can't find it any more in the documentation.

Sorry in advance if I'm just being blind.

Answer 1

Late reply, but better late than never.

You can map the classes not under your control to one you created/do control using AutoMapper, ValueInjector, etc. Then you are free to apply any attributes necessary.

Edit: Solution from JSON.NET Documentation using IContractResolver

public class DynamicContractResolver : DefaultContractResolver
{
  private readonly char _startingWithChar;
  public DynamicContractResolver(char startingWithChar)
  {
    _startingWithChar = startingWithChar;
  }

  protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
  {
    IList<JsonProperty> properties = base.CreateProperties(type, memberSerialization);

    // only serializer properties that start with the specified character
    properties =
      properties.Where(p => p.PropertyName.StartsWith(_startingWithChar.ToString())).ToList();

    return properties;
  }
}

public class Book
{
  public string BookName { get; set; }
  public decimal BookPrice { get; set; }
  public string AuthorName { get; set; }
  public int AuthorAge { get; set; }
  public string AuthorCountry { get; set; }
}

IContractResolver Example

    Book book = new Book
{
  BookName = "The Gathering Storm",
  BookPrice = 16.19m,
  AuthorName = "Brandon Sanderson",
  AuthorAge = 34,
  AuthorCountry = "United States of America"
};

string startingWithA = JsonConvert.SerializeObject(book, Formatting.Indented,
  new JsonSerializerSettings { ContractResolver = new DynamicContractResolver('A') });

// {
//   "AuthorName": "Brandon Sanderson",
//   "AuthorAge": 34,
//   "AuthorCountry": "United States of America"
// }

string startingWithB = JsonConvert.SerializeObject(book, Formatting.Indented,
  new JsonSerializerSettings { ContractResolver = new DynamicContractResolver('B') });

// {
//   "BookName": "The Gathering Storm",
//   "BookPrice": 16.19
// }