Since Json.NET is open source and its MIT license allows modification, the easiest solution may be to adapt its ExpandoObjectConverter
to your needs:
/// <summary>
/// Converts an ExpandoObject to and from JSON, handling object references.
/// </summary>
public class ObjectReferenceExpandoObjectConverter : JsonConverter
{
// Adapted from https://github.com/JamesNK/Newtonsoft.Json/blob/master/Src/Newtonsoft.Json/Converters/ExpandoObjectConverter.cs
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
// can write is set to false
throw new NotImplementedException();
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
return ReadValue(serializer, reader);
}
private object ReadValue(JsonSerializer serializer, JsonReader reader)
{
while (reader.TokenType == JsonToken.Comment)
{
if (!reader.Read())
throw reader.CreateException("Unexpected end when reading ExpandoObject.");
}
switch (reader.TokenType)
{
case JsonToken.StartObject:
return ReadObject(serializer, reader);
case JsonToken.StartArray:
return ReadList(serializer, reader);
default:
if (JsonTokenUtils.IsPrimitiveToken(reader.TokenType))
return reader.Value;
throw reader.CreateException("Unexpected token when converting ExpandoObject");
}
}
private object ReadList(JsonSerializer serializer, JsonReader reader)
{
IList<object> list = new List<object>();
while (reader.Read())
{
switch (reader.TokenType)
{
case JsonToken.Comment:
break;
default:
object v = ReadValue(serializer, reader);
list.Add(v);
break;
case JsonToken.EndArray:
return list;
}
}
throw reader.CreateException("Unexpected end when reading ExpandoObject.");
}
private object ReadObject(JsonSerializer serializer, JsonReader reader)
{
IDictionary<string, object> expandoObject = null;
object referenceObject = null;
while (reader.Read())
{
switch (reader.TokenType)
{
case JsonToken.PropertyName:
string propertyName = reader.Value.ToString();
if (!reader.Read())
throw new InvalidOperationException("Unexpected end when reading ExpandoObject.");
object v = ReadValue(serializer, reader);
if (propertyName == "$ref")
{
var id = (v == null ? null : Convert.ToString(v, CultureInfo.InvariantCulture));
referenceObject = serializer.ReferenceResolver.ResolveReference(serializer, id);
}
else if (propertyName == "$id")
{
var id = (v == null ? null : Convert.ToString(v, CultureInfo.InvariantCulture));
serializer.ReferenceResolver.AddReference(serializer, id, (expandoObject ?? (expandoObject = new ExpandoObject())));
}
else
{
(expandoObject ?? (expandoObject = new ExpandoObject()))[propertyName] = v;
}
break;
case JsonToken.Comment:
break;
case JsonToken.EndObject:
if (referenceObject != null && expandoObject != null)
throw reader.CreateException("ExpandoObject contained both $ref and real data");
return referenceObject ?? expandoObject;
}
}
throw reader.CreateException("Unexpected end when reading ExpandoObject.");
}
public override bool CanConvert(Type objectType)
{
return (objectType == typeof(ExpandoObject));
}
public override bool CanWrite
{
get { return false; }
}
}
public static class JsonTokenUtils
{
// Adapted from https://github.com/JamesNK/Newtonsoft.Json/blob/master/Src/Newtonsoft.Json/Utilities/JsonTokenUtils.cs
public static bool IsPrimitiveToken(this JsonToken token)
{
switch (token)
{
case JsonToken.Integer:
case JsonToken.Float:
case JsonToken.String:
case JsonToken.Boolean:
case JsonToken.Undefined:
case JsonToken.Null:
case JsonToken.Date:
case JsonToken.Bytes:
return true;
default:
return false;
}
}
}
public static class JsonReaderExtensions
{
public static JsonSerializationException CreateException(this JsonReader reader, string format, params object[] args)
{
// Adapted from https://github.com/JamesNK/Newtonsoft.Json/blob/master/Src/Newtonsoft.Json/JsonPosition.cs
var lineInfo = reader as IJsonLineInfo;
var path = (reader == null ? null : reader.Path);
var message = string.Format(CultureInfo.InvariantCulture, format, args);
if (!message.EndsWith(Environment.NewLine, StringComparison.Ordinal))
{
message = message.Trim();
if (!message.EndsWith(".", StringComparison.Ordinal))
message += ".";
message += " ";
}
message += string.Format(CultureInfo.InvariantCulture, "Path '{0}'", path);
if (lineInfo != null && lineInfo.HasLineInfo())
message += string.Format(CultureInfo.InvariantCulture, ", line {0}, position {1}", lineInfo.LineNumber, lineInfo.LinePosition);
message += ".";
return new JsonSerializationException(message);
}
}
And then use it like:
var settings = new JsonSerializerSettings { PreserveReferencesHandling = PreserveReferencesHandling.Objects, ReferenceLoopHandling = ReferenceLoopHandling.Serialize };
settings.Converters.Add(new ObjectReferenceExpandoObjectConverter());
dynamic d = JsonConvert.DeserializeObject<ExpandoObject>(json, settings);
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