private static Func <DeserializationContext, object> ForComplex(Type type, TypeOptions options, Func <Type, TypeDescriptor> descriptorSource)
{
var info = type.GetTypeInfo();
if (info.IsClass && info.GetConstructor(Type.EmptyTypes) == null)
{
return(reader => throw new JsonException(info.IsAbstract
? $"Type {type} is abstract. Add {nameof(ITypeSelector)} to {nameof(SerializationSettings)} in order to deserialize this type."
: $"Type {type} must define public parameterless constructor."));
}
var properties = info
.GetProperties(BindingFlags.Instance | BindingFlags.Public)
.Where(i => i.SetMethod != null && i.GetMethod != null)
.Select(i => new { Property = (MemberInfo)i, Setter = ReflectionUtils.BuildSetter(i), Descriptor = descriptorSource(i.PropertyType) });
var fields = info
.GetFields(BindingFlags.Instance | BindingFlags.Public)
.Select(i => new { Property = (MemberInfo)i, Setter = ReflectionUtils.BuildFieldSetter(i), Descriptor = descriptorSource(i.FieldType) });
var all = properties
.Concat(fields)
.SelectMany(i => JsonNames(i.Property).Select(j => new PropertyBinding {
Name = j, Setter = i.Setter, Descriptor = i.Descriptor
}))
.GroupBy(i => i.Name)
.ToDictionary(i => i.Key, i => i.First());
var constructor = info.IsClass
? ReflectionUtils.BuildConstructor(type)
: () => Activator.CreateInstance(typeof(Box <>).MakeGenericType(type));
//struct types are internally wrapped into Box<T> type (see ReflectionUtils)
var unwrapper = !info.IsClass
? new Func <object, object>(i => ((IBox)i).Value)
: null;
return(context =>
{
var bufferPart = new BufferPart();
var reader = context.Reader;
var token = reader.Read(ref bufferPart, out var _);
if (token == JsonToken.Null)
{
return info.IsClass ? (object)null : throw new JsonException($"Unable to assign null value to struct type near line {reader.Line}, column {reader.Column}.");
}
if (token != JsonToken.ObjectStart)
{
throw Exceptions.BadToken(reader, token, JsonToken.ObjectStart);
}
var target = constructor();
var deferred = ReadProperties(target, context, all);
var unwrapped = unwrapper != null?unwrapper(target) : target;
if (deferred == null)
{
return unwrapped;
}
foreach (var entry in deferred)
{
var runtimeType = entry.Selector.FindPropertyType(entry.Binding.Name, unwrapped);
var descriptor = context.Catalog.GetDescriptor(runtimeType, options);
using (reader.LoadSnapshot(entry.Snapshot))
entry.Binding.Setter(target, descriptor.Reader(context));
}
return unwrapper != null?unwrapper(target) : target;
});
}
