How Do I Configure Json.NET Custom Serialization?

Question

For reasons beyond my control, I have data coming back from an external service being formatted as an array of array of string: [["string_one", "string_two"]]

I am trying to deserialize this into an object with two properties:

public class MyObject
{
    public string PropertyOne { get; set; }
    public string PropertyTwo { get; set; }
}

I'm using Json.NET for all JSON serialization/deserialization. When I attempt to convert the array of array of string, I get an exception saying that JsonArray can't be converted to MyObject. What's the appropriate way to implement this?

score 2 · Answer 1 · answered Sep 28 '11 at 15:35

2

There is quite a big discrepancy between your target object and the JSON. You could do the mapping manually:

string json = "[[\"string_one\", \"string_two\"]]";
dynamic result = JsonConvert.DeserializeObject(json);
var myObject = new MyObject
{
    PropertyOne = result[0][0],
    PropertyTwo = result[0][1]
};

answered Sep 28 '11 at 15:35

Darin Dimitrov

1,023,142
271
3,287
2,928

The discrepancy is unavoidable, sadly. – Sep 28 '11 at 15:45

score 2 · Accepted Answer · answered Sep 28 '11 at 18:03

Ended up implementing this using a JsonConverter. I changed MyObject to look like:

[JsonConverter(typeof(MyObjectConverter))]
public class MyObject
{
    public string PropertyOne { get; set; }
    public string PropertyTwo { get; set; }
}

And then implemented MyObjectConverter:

public class MyObjectConverter : JsonConverter
{
    public override object ReadJson (JsonReader reader, Type objectType, Object existingValue, JsonSerializer serializer)
    {
        int pos = 0;
        string[] objectIdParts = new string[2];

        while (reader.Read())
        {
            if (pos < 1)
            {
                if (reader.TokenType == JsonToken.String)
                {
                    objectIdParts[pos] = reader.Value.ToString();
                    pos++;
                }
            }
            // read until the end of the JsonReader
        }

        return new MyObject(objectIdParts);
    }

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

    public override bool CanWrite {
        get {
            return base.CanWrite;
        }
    }

    public override bool CanRead { get { return true; } }
    public override bool CanConvert (Type objectType) 
    {
        return true;
    }
}

score 1 · Answer 3 · answered Sep 28 '11 at 15:32

1

Honestly, I'd just deserialize it as string[][] and map that within your domain layer. The amount of time you'll spend messing around with custom serialization is rarely worth it.

answered Sep 28 '11 at 15:32

Richard Szalay

83,269
19
178
237

1

I dislike answers like this b/c it doesn't help people who have this generic problem who will read this answer in the future... – Henley Dec 03 '13 at 18:16
@Henley - Luckily there's more than one answer to choose from ;) – Richard Szalay Dec 03 '13 at 20:12

How Do I Configure Json.NET Custom Serialization?

3 Answers3

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