public override bool CanConvert(Type objectType)
{
foreach (var candidate in PolymorphicCandidateProvider.GetAll())
{
foreach (var @interface in candidate.Type.GetInterfaces())
{
if (@interface.IsAssignableFrom(objectType))
{
return(true);
}
}
}
return(false);
}
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
var o = new JObject();
var candidate = PolymorphicCandidateProvider.Get(value.GetType());
if (candidate == null)
{
throw new Exception($"Value (of type {value.GetType()}) must be a [Form] when saving to an interface type property for polymorphic serialization to work");
}
o["type"] = candidate.Id;
o["name"] = candidate.Type.GetCustomAttribute <DisplayAttribute>()?.Name ?? Humanizer.Humanize(candidate.Type.Name);
o["value"] = JObject.FromObject(value, JsonWebSerializer);
o.WriteTo(writer);
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
if (!objectType.IsInterface)
{
return(JObject.Load(reader).ToObject(objectType));
}
if (reader.TokenType == JsonToken.Null)
{
return(null);
}
if (reader.TokenType != JsonToken.StartObject)
{
Logger.LogInformation("Polymorphic properties must be JSON objects of the schema: { type: ..., value: {...} }");
return(null);
}
var container = JObject.Load(reader);
var typeId = container.Value <string>("type");
if (typeId == null)
{
Logger.LogInformation("Container object is missing the required type property");
return(null);
}
var candidate = PolymorphicCandidateProvider.Get(typeId);
if (candidate == null)
{
Logger.LogInformation($"No such type: {typeId}");
return(null);
}
var value = container.Value <JObject>("value");
return(value.ToObject(candidate.Type));
}
