Parse non-array JSON object as array with Json.net

arrays, c#, deserialization, json, json.net

Solution

A custom JSON.NET converter might do the trick here. It's not that hard.

For a DateTime property you might do it as follows. Just decorate the property in question with the custom converter.

[JsonObject(MemberSerialization.OptIn)]
public class MyClass
{
    [JsonProperty(PropertyName = "creation_date")]
    [JsonConverter(typeof(UnixDateTimeConverter))]
    public DateTime CreationDate { get; set; }
}

JSON.NET provides most of the plumbing. Just derive from a base converter.

public class UnixDateTimeConverter : DateTimeConverterBase
{
    public override void WriteJson(JsonWriter writer, object value, 
                                   JsonSerializer serializer)
    { ...}

    public override void WriteJson(JsonWriter writer, object value, 
                                   JsonSerializer serializer)
    { ... } 
}  

All you have to do is implement the ReadJson (deserialization) and WriteJson (serialization) methods.

You can find a complete example here:

Writing a custom Json.NET DateTime Converter

For your particular problem you need a bit more control. Try the following type of converter:

public class Contact
{ 
   private List<Address> _addresses = new List<Address>();       
   public IEnumerable<Address> Addresses { get { return _addresses; }
}

public class ContactConverter : CustomCreationConverter<Contact>
{
    public override Contact Create(Type objectType)
    {
        return new Contact();
    }

    public override object ReadJson(JsonReader reader, Type objectType, object 
        existingValue, JsonSerializer serializer)
    {
        var mappedObj = new Contact();

        // Parse JSON data here
        // ...

        return mappedObj;
    }
}

Using a custom converter like the one above you can parse the JSON data yourself and compose the Contact object(s) as you please.

I modified an example I found here:

JSON.NET Custom Converters–A Quick Tour

In this case you need to pass the custom converter when desearilizing.

Contact contact = 
    JsonConvert.DeserializeObject<Contact>(json, new ContactConverter());

Problem

Original source