// Used in serializing enums on the client
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
if (value == null)
{
writer.WriteNull();
return;
}
var enumType = value.GetType();
if (!enumType.IsEnum)
{
throw new Exception($"{nameof(JsonEnumConverter)}: unexpected conversion type {enumType}; expected enum.");
}
var handler = KnownEnumTypes.GetEnumHandler(enumType);
if (handler.IsFlagSet)
{
writer.WriteStartArray();
var strings = handler.ConvertFlagsEnumValueToOutputStringList(value);
foreach (var sv in strings)
{
writer.WriteValue(sv);
}
writer.WriteEndArray();
}
else
{
var sv = handler.ConvertEnumValueToOutputString(value);
writer.WriteValue(sv);
}
}//method
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
var enumType = objectType;
var nullable = ReflectionHelper.CheckNullable(ref enumType);
if (!enumType.IsEnum)
{
throw new Exception($"{nameof(JsonEnumConverter)}: unexpected conversion type {enumType}; expected enum.");
}
var enumHandler = KnownEnumTypes.GetEnumHandler(enumType);
var enumInfo = KnownEnumTypes.GetEnumHandler(enumType);
// check null
if (reader.TokenType == JsonToken.Null)
{
if (!nullable)
{
throw new Exception($"{nameof(JsonEnumConverter)}: input value null cannot be converted to type {enumType}.");
}
}
var tokenReader = (JTokenReader)reader;
if (enumInfo.IsFlagSet)
{
switch (tokenReader.CurrentToken)
{
case JArray jArr:
if (jArr.Count == 0)
{
return(enumInfo.NoneValue);
}
var strings = jArr.Select(v => v.ToString()).ToArray();
var res = enumHandler.ConvertStringListToFlagsEnumValue(strings);
reader.Skip();
return(res);
default:
throw new Exception($"{nameof(JsonEnumConverter)}: invalid input value for Flags enum type {enumType}, expected string array.");
}
}
else
{
switch (tokenReader.CurrentToken)
{
case JValue jv:
if (!(jv.Value is string s))
{
throw new Exception($"{nameof(JsonEnumConverter)}: invalid input value for enum type {objectType}, expected string.");
}
var res = enumHandler.ConvertStringToEnumValue(s);
return(res);
default:
throw new Exception($"{nameof(JsonEnumConverter)}: invalid input value for enum type {objectType}, expected string.");
} //switch
} //else
}
// We want to handle enum, enum? types. For arrays of enums, we do not want to interfere, the main serializer will handle
// array, and only come here for individual values.
public override bool CanConvert(Type objectType)
{
if (objectType.IsEnum)
{
return(true);
}
if (!objectType.IsValueType)
{
return(false);
}
// try lookup and register
var enumInfo = KnownEnumTypes.GetEnumHandler(objectType);
return(enumInfo != null);
}