.NET Deserializing JSON to multiple types

.net, deserialization, json

Solution

I think it's likely you'll need to deserialize the Json then construct the objects from there. Deserializing directly to `Cat` or `Dog` won't be possible as the deserializer won't know how to construct these objects specifically.

Edit: borrowing heavily from Deserializing heterogenous JSON array into covariant List<> using JSON.NET

Something like this would work:

interface IAnimal
{
    string Type { get; set; }
}

class Cat : IAnimal
{
    public string CatName { get; set; }
    public string Type { get; set; }
}

class Dog : IAnimal
{
    public string DogName { get; set; }
    public string Type { get; set; }
}

class AnimalJson
{
    public IEnumerable<IAnimal> Items { get; set; }
}

class Animal
{
    public string Type { get; set; }
    public string Name { get; set; }
}

class AnimalItemConverter : Newtonsoft.Json.Converters.CustomCreationConverter<IAnimal>
{
    public override IAnimal Create(Type objectType)
    {
        throw new NotImplementedException();
    }

    public IAnimal Create(Type objectType, JObject jObject)
    {
        var type = (string)jObject.Property("type");

        switch (type)
        {
            case "cat":
                return new Cat();
            case "dog":
                return new Dog();
        }

        throw new ApplicationException(String.Format("The animal type {0} is not supported!", type));
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        // Load JObject from stream 
        JObject jObject = JObject.Load(reader);

        // Create target object based on JObject 
        var target = Create(objectType, jObject);

        // Populate the object properties 
        serializer.Populate(jObject.CreateReader(), target);

        return target;
    }
}

string json = "{ items: [{ type: \"cat\", catName: \"tom\" }, { type: \"dog\", dogName: \"fluffy\" }] }";
object obj = JsonConvert.DeserializeObject<AnimalJson>(json, new AnimalItemConverter());

Problem

Original source

Related problems

• Deserializing heterogenous JSON array into covariant List<> using Json.NET
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