/// <summary>
/// Central interception point for well-known type formatting. Any well-known types which
/// don't need special handling can fall back to WriteMessage. We avoid assuming that the
/// values are using the embedded well-known types, in order to allow for dynamic messages
/// in the future.
/// </summary>
private void WriteWellKnownTypeValue(TextWriter writer, MessageDescriptor descriptor, object value)
{
// Currently, we can never actually get here, because null values are always handled by the caller. But if we *could*,
// this would do the right thing.
if (value == null)
{
WriteNull(writer);
return;
}
// For wrapper types, the value will either be the (possibly boxed) "native" value,
// or the message itself if we're formatting it at the top level (e.g. just calling ToString on the object itself).
// If it's the message form, we can extract the value first, which *will* be the (possibly boxed) native value,
// and then proceed, writing it as if we were definitely in a field. (We never need to wrap it in an extra string...
// WriteValue will do the right thing.)
if (descriptor.IsWrapperType())
{
if (value is IMessage)
{
var message = (IMessage)value;
value = message.Descriptor.Fields[WrappersReflection.WrapperValueFieldNumber].Accessor.GetValue(message);
}
WriteValue(writer, value);
return;
}
if (descriptor.FullName == Timestamp.Descriptor.FullName)
{
WriteTimestamp(writer, (IMessage)value);
return;
}
if (descriptor.FullName == Duration.Descriptor.FullName)
{
WriteDuration(writer, (IMessage)value);
return;
}
if (descriptor.FullName == FieldMask.Descriptor.FullName)
{
WriteFieldMask(writer, (IMessage)value);
return;
}
if (descriptor.FullName == Struct.Descriptor.FullName)
{
WriteStruct(writer, (IMessage)value);
return;
}
if (descriptor.FullName == ListValue.Descriptor.FullName)
{
var fieldAccessor = descriptor.Fields[ListValue.ValuesFieldNumber].Accessor;
WriteList(writer, (IList)fieldAccessor.GetValue((IMessage)value));
return;
}
if (descriptor.FullName == Value.Descriptor.FullName)
{
WriteStructFieldValue(writer, (IMessage)value);
return;
}
if (descriptor.FullName == Any.Descriptor.FullName)
{
WriteAny(writer, (IMessage)value);
return;
}
WriteMessage(writer, (IMessage)value);
}
