how to get newtonsoft to deserialize yes and no to boolean

CodeChops picture CodeChops · Jan 25, 2013 · Viewed 23.5k times · Source

NOTE: I have provided the solution at the bottom of this feed.

I have a C# Win 8 app where I'm de-serializing some json that looks like this:

{
    'Unit': [
        {
            'name':'House 123',
            isAvailable:'no'
        },
        {
            'name':'House 456',
            isAvailable:'yes'
        }]
}

into a class that uses this interface:

public interface IUnit
{
    string Name { get; }
    bool isAvailable { get; }
}

But Newtonsoft throws an error:

Unexpected character encountered while parsing value: n. Path 'Unit[0].isAvailable, line 1, position 42.

Is there a way to extend Newtonsoft to parse yes/no or 1/0 based on the resulting object property type of bool? Right now it only works for true/false.

There are several posts on custom converters for classes, but not a primitive type like bool.

Any suggestions?

Answer

Craig Stuntz picture Craig Stuntz · Jan 25, 2013
public class MyBooleanConverter : JsonConverter
{
    public override bool CanWrite { get { return false; } }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        throw new NotImplementedException();
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        var value = reader.Value;

        if (value == null || String.IsNullOrWhiteSpace(value.ToString()))
        {
            return false;
        }

        if ("yes".Equals(value, StringComparison.OrdinalIgnoreCase))
        {
            return true;
        }

        return false;
    }

    public override bool CanConvert(Type objectType)
    {
        if (objectType == typeof(String) || objectType == typeof(Boolean))
        {
            return true;
        }
        return false;
    }
}


public interface IUnit
{
    string Name { get; }

    [JsonConverter(typeof(MyBooleanConverter))]
    bool isAvailable { get; }
}