public AdaptiveFallbackElement ParseFallback(JToken fallbackJSON, JsonSerializer serializer, string objectId, AdaptiveInternalID internalId)
{
// Handle fallback as a string ("drop")
if (fallbackJSON.Type == JTokenType.String)
{
var str = fallbackJSON.Value <string>();
if (str == AdaptiveFallbackElement.drop)
{
// fallback is initialized with "drop" property and empty content
return(new AdaptiveFallbackElement(AdaptiveFallbackElement.AdaptiveFallbackType.Drop));
}
throw new AdaptiveSerializationException("The only valid string value for the fallback property is 'drop'.");
}
// handle fallback as an object
else if (fallbackJSON.Type == JTokenType.Object)
{
// fallback value is a JSON object. parse it and add it as fallback content. For more details, refer to
// the giant comment on ID collision detection in ParseContext.cpp (ObjectModel).
ParseContext.PushElement(objectId, internalId);
var elem = new AdaptiveFallbackElement(fallbackJSON.ToObject <AdaptiveTypedElement>());
ParseContext.PopElement();
return(elem);
}
// Should never get here. Instead should be thrown in CanConvert()
throw new AdaptiveSerializationException("Invalid value for fallback");
}
public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
{
var token = reader.TokenType;
switch (token)
{
case JsonToken.String:
{
AdaptiveFallbackElement adaptiveFallbackElement = new AdaptiveFallbackElement();
string stringValue = (string)reader.Value;
if (stringValue == "drop")
{
adaptiveFallbackElement.Type = AdaptiveFallbackElement.AdaptiveFallbackType.Drop;
}
else
{
throw new AdaptiveSerializationException("The only valid string value for the fallback property is 'drop'.");
}
return(adaptiveFallbackElement);
}
case JsonToken.StartObject:
{
var jObject = JObject.Load(reader);
var typeName = AdaptiveTypedElementConverter.GetElementTypeName(objectType, jObject);
Type type;
if (!AdaptiveTypedElementConverter.TypedElementTypes.Value.TryGetValue(typeName, out type))
{
type = typeof(AdaptiveUnknownElement);
}
IsInFallback = true;
string objectId = jObject.Value <string>("id");
AdaptiveInternalID internalID = AdaptiveInternalID.Next();
// Handle deserializing unknown element
ParseContext.PushElement(objectId, internalID);
var result = (AdaptiveTypedElement)Activator.CreateInstance(type);
serializer.Populate(jObject.CreateReader(), result);
ParseContext.PopElement();
IsInFallback = false;
AdaptiveFallbackElement adaptiveFallbackElement = new AdaptiveFallbackElement();
adaptiveFallbackElement.Type = AdaptiveFallbackElement.AdaptiveFallbackType.Content;
adaptiveFallbackElement.Content = result;
return(adaptiveFallbackElement);
}
default:
{
throw new AdaptiveSerializationException("Invalid value for fallback");
}
}
}
public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
{
AdaptiveFallbackElement fallback = value as AdaptiveFallbackElement;
if (fallback != null)
{
if (fallback.Type != AdaptiveFallbackElement.AdaptiveFallbackType.None)
{
if (fallback.Type == AdaptiveFallbackElement.AdaptiveFallbackType.Drop)
{
writer.WriteValue(AdaptiveFallbackElement.drop);
}
else
{
serializer.Serialize(writer, fallback.Content);
}
}
}
else
{
throw new AdaptiveSerializationException("Unable to safely cast to AdaptiveFallbackElement");
}
}