serialization: Implement JsonSerializer loading functionality

include/ki/pclass/Casters.h

@@ -34,6 +34,12 @@ namespace detail
 	template <>
 	struct is_json_assignable<std::string> : std::true_type {};
 
+	/**
+	 * std::u16string can be assigned to a json object.
+	 */
+	template <>
+	struct is_json_assignable<std::u16string> : std::true_type {};
+
 	/**
 	 * value_caster specialization for the generic case of casting
 	 * any json-assignable value to a json object.
@@ -163,6 +169,34 @@ namespace detail
 		}
 	};
 
+	/**
+	 * Caster implementation for casting from json to any
+	 * primitive type.
+	 */
+	template <typename DestT>
+	struct value_caster<nlohmann::json, DestT>
+		: value_caster_impl<nlohmann::json, DestT>
+	{
+		DestT cast_value(const nlohmann::json &value) const override
+		{
+			return value;
+		}
+	};
+
+	/**
+	 * Caster implementation for casting from json to a
+	 * std::string.
+	 */
+	template <>
+	struct value_caster<nlohmann::json, std::string>
+		: value_caster_impl<nlohmann::json, std::string>
+	{
+		std::string cast_value(const nlohmann::json &value) const override
+		{
+			return value;
+		}
+	};
+
 	/**
 	 * A utility to call ValueCaster::declare<SrcT, DestT> with
 	 * bi<N> and bui<N> as the destination type.

include/ki/pclass/Property.h

@@ -34,6 +34,8 @@ namespace pclass
 		virtual bool is_dynamic() const;
 
 		virtual Value get_value() const = 0;
+		virtual void set_value(Value value) = 0;
+
 		virtual const PropertyClass *get_object() const = 0;
 		virtual void set_object(std::unique_ptr<PropertyClass> &object) = 0;
 
@@ -70,12 +72,14 @@ namespace pclass
 		virtual void set_element_count(std::size_t size) = 0;
 
 		Value get_value() const final override;
+		void set_value(Value value) final override;
 		const PropertyClass *get_object() const final override;
 		void set_object(std::unique_ptr<PropertyClass> &object) final override;
 		void write_value_to(BitStream &stream) const final override;
 		void read_value_from(BitStream &stream) final override;
 
 		virtual Value get_value(int index) const = 0;
+		virtual void set_value(Value value, int index) = 0;
 		virtual const PropertyClass *get_object(int index) const = 0;
 		virtual void set_object(std::unique_ptr<PropertyClass> &object, int index) = 0;
 		virtual void write_value_to(BitStream &stream, int index) const = 0;

include/ki/pclass/StaticProperty.h

@@ -1,5 +1,6 @@
 #pragma once
 #include "ki/pclass/Property.h"
+#include "ki/pclass/PropertyClass.h"
 #include "ki/util/exception.h"
 
 namespace ki
@@ -42,6 +43,13 @@ namespace pclass
 			return Value::make_reference<ValueT>(prop.m_value);
 		}
 
+		static void set_value(StaticProperty<ValueT> &prop, Value value)
+		{
+			prop.m_value = value
+				.dereference<ValueT>()
+				.get<ValueT>();
+		}
+
 		static const PropertyClass *get_object(const StaticProperty<ValueT> &prop)
 		{
 			// ValueT does not derive from PropertyClass, and so, this property is not
@@ -106,6 +114,13 @@ namespace pclass
 			return Value::make_reference<nonpointer_type>(*prop.m_value);
 		}
 
+		static void set_value(StaticProperty<ValueT> &prop, Value value)
+		{
+			prop.m_value = value
+				.dereference<nonpointer_type>()
+				.take<nonpointer_type>();
+		}
+
 		static const PropertyClass *get_object(const StaticProperty<ValueT> &prop)
 		{
 			// ValueT does not derive from PropertyClass, and so, this property is not
@@ -173,6 +188,13 @@ namespace pclass
 			return Value::make_reference<nonpointer_type>(*prop.m_value);
 		}
 
+		static void set_value(StaticProperty<ValueT> &prop, Value value)
+		{
+			prop.m_value = value
+				.dereference<nonpointer_type>()
+				.take<nonpointer_type>();
+		}
+
 		static const PropertyClass *get_object(const StaticProperty<ValueT> &prop)
 		{
 			// ValueT does derive from PropertyClass, and we have a pointer to an instance
@@ -241,6 +263,13 @@ namespace pclass
 			return Value::make_reference<ValueT>(prop.m_value);
 		}
 
+		static void set_value(StaticProperty<ValueT> &prop, Value value)
+		{
+			prop.m_value = value
+				.dereference<ValueT>()
+				.get<ValueT>();
+		}
+
 		static const PropertyClass *get_object(const StaticProperty<ValueT> &prop)
 		{
 			// ValueT does derive from PropertyClass, and we have an instance of ValueT,
@@ -343,6 +372,11 @@ namespace pclass
 			return value_object_helper<ValueT>::get_value(prop);
 		}
 
+		static void set_value(StaticProperty<ValueT> &prop, Value value)
+		{
+			return value_object_helper<ValueT>::set_value(prop, value);
+		}
+
 		static const PropertyClass *get_object(const StaticProperty<ValueT> &prop)
 		{
 			return value_object_helper<ValueT>::get_object(prop);
@@ -414,6 +448,11 @@ namespace pclass
 			return value_helper<ValueT>::get_value(*this);
 		}
 
+		void set_value(Value value) override
+		{
+			value_helper<ValueT>::set_value(*this, value);
+		}
+
 		const PropertyClass *get_object() const override
 		{
 			return value_helper<ValueT>::get_object(*this);

include/ki/pclass/TypeSystem.h

@@ -1,6 +1,7 @@
 #pragma once
 #include <vector>
 #include <unordered_map>
+#include <json.hpp>
 #include "ki/pclass/HashCalculator.h"
 #include "ki/pclass/Casters.h"
 #include "ki/pclass/types/Type.h"
@@ -32,6 +33,8 @@ namespace pclass
 		PrimitiveType<ValueT> &define_primitive(const std::string &name)
 		{
 			detail::caster_declarer<ValueT>::declare();
+			ValueCaster::declare<nlohmann::json, ValueT>();
+
 			auto *type = new PrimitiveType<ValueT>(name, *this);
 			define_type(std::unique_ptr<Type>(
 				dynamic_cast<Type *>(type)
@@ -58,6 +61,8 @@ namespace pclass
 		CppEnumType<EnumT> &define_enum(const std::string &name)
 		{
 			detail::caster_declarer<EnumT>::declare();
+			ValueCaster::declare<nlohmann::json, EnumT>();
+
 			auto *type = new CppEnumType<EnumT>(name, *this);
 			define_type(std::unique_ptr<Type>(
 				dynamic_cast<Type *>(type)

include/ki/pclass/Value.h

@@ -79,6 +79,11 @@ namespace pclass
 			 * @param[in] ptr The pointer to deallocate.
 			 */
 			virtual void deallocate(void *ptr) const = 0;
+
+			/**
+			 * Create a copy of this deallocator.
+			 */
+			virtual value_deallocator_base *copy() const = 0;
 		};
 
 		/**
@@ -92,18 +97,25 @@ namespace pclass
 				// By default, now that we have the proper type, just delete it.
 				delete static_cast<T *>(ptr);
 			}
+
+			value_deallocator_base *copy() const override
+			{
+				return new value_deallocator<T>();
+			}
 		};
 
 		/**
-		* TODO: Documentation
-		*/
+		 * TODO: Documentation
+		 */
 		class ValueDeallocator
 		{
 			// Allow Value to call make<T>() and the default constructor
 			friend Value;
 
 		public:
+			ValueDeallocator(ValueDeallocator &that);
 			ValueDeallocator(ValueDeallocator &&that) noexcept;
+			ValueDeallocator &operator=(ValueDeallocator &that);
 			ValueDeallocator &operator=(ValueDeallocator &&that) noexcept;
 			~ValueDeallocator();
 
@@ -220,7 +232,9 @@ namespace pclass
 	class Value
 	{
 	public:
+		Value(Value &that);
 		Value(Value &&that) noexcept;
+		Value &operator=(Value &that);
 		Value &operator=(Value &&that) noexcept;
 		~Value();
 

include/ki/pclass/VectorProperty.h

@@ -39,7 +39,15 @@ namespace pclass
 			// Ensure index is within bounds
 			if (index < 0 || index >= prop.size())
 				throw runtime_error("Index out of bounds.");
-			return Value::make_reference(prop.at(index));
+			return Value::make_reference<ValueT>(prop.at(index));
+		}
+
+		static void set_value(VectorProperty<ValueT> &prop,
+			Value value, const int index)
+		{
+			prop.at(index) = value
+				.dereference<ValueT>()
+				.get<ValueT>();
 		}
 
 		static const PropertyClass *get_object(const VectorProperty<ValueT> &prop, const int index)
@@ -79,6 +87,8 @@ namespace pclass
 		>::type
 	>
 	{
+		using nonpointer_type = typename std::remove_pointer<ValueT>::type;
+
 		static ValueT copy(VectorProperty<ValueT> &prop, const int index)
 		{
 			// Ensure index is within bounds
@@ -95,7 +105,15 @@ namespace pclass
 			// Ensure index is within bounds
 			if (index < 0 || index >= prop.size())
 				throw runtime_error("Index out of bounds.");
-			return Value::make_reference(*prop.at(index));
+			return Value::make_reference<nonpointer_type>(*prop.at(index));
+		}
+
+		static void set_value(VectorProperty<ValueT> &prop,
+			Value value, const int index)
+		{
+			prop.at(index) = value
+				.dereference<nonpointer_type>()
+				.take<nonpointer_type>();
 		}
 
 		static const PropertyClass *get_object(const VectorProperty<ValueT> &prop, const int index)
@@ -135,6 +153,8 @@ namespace pclass
 		>::type
 	>
 	{
+		using nonpointer_type = typename std::remove_pointer<ValueT>::type;
+
 		static ValueT copy(VectorProperty<ValueT> &prop, const int index)
 		{
 			// The copy constructor for all pointers is to copy the pointer
@@ -147,7 +167,15 @@ namespace pclass
 			// Ensure index is within bounds
 			if (index < 0 || index >= prop.size())
 				throw runtime_error("Index out of bounds.");
-			return Value::make_reference(*prop.at(index));
+			return Value::make_reference<nonpointer_type>(*prop.at(index));
+		}
+
+		static void set_value(VectorProperty<ValueT> &prop,
+			Value value, const int index)
+		{
+			prop.at(index) = value
+				.dereference<nonpointer_type>()
+				.take<nonpointer_type>();
 		}
 
 		static const PropertyClass *get_object(const VectorProperty<ValueT> &prop, const int index)
@@ -214,7 +242,15 @@ namespace pclass
 			// Ensure index is within bounds
 			if (index < 0 || index >= prop.size())
 				throw runtime_error("Index out of bounds.");
-			return Value::make_reference(prop.at(index));
+			return Value::make_reference<ValueT>(prop.at(index));
+		}
+
+		static void set_value(VectorProperty<ValueT> &prop,
+			Value value, const int index)
+		{
+			prop.at(index) = value
+				.dereference<ValueT>()
+				.get<ValueT>();
 		}
 
 		static const PropertyClass *get_object(const VectorProperty<ValueT> &prop, const int index)
@@ -326,18 +362,24 @@ namespace pclass
 			return vector_value_object_helper<ValueT>::copy(prop, index);
 		}
 
-		static const PropertyClass *get_object(const VectorProperty<ValueT> &prop,
-			const int index)
-		{
-			return vector_value_object_helper<ValueT>::get_object(prop, index);
-		}
-
 		static Value get_value(const VectorProperty<ValueT> &prop,
 			const int index)
 		{
 			return vector_value_object_helper<ValueT>::get_value(prop, index);
 		}
 
+		static void set_value(VectorProperty<ValueT> &prop,
+			Value value, const int index)
+		{
+			vector_value_object_helper<ValueT>::set_value(prop, value, index);
+		}
+
+		static const PropertyClass *get_object(const VectorProperty<ValueT> &prop,
+			const int index)
+		{
+			return vector_value_object_helper<ValueT>::get_object(prop, index);
+		}
+
 		static void set_object(VectorProperty<ValueT> &prop, 
 			std::unique_ptr<PropertyClass> &object, const int index)
 		{
@@ -405,6 +447,13 @@ namespace pclass
 			return vector_value_helper<ValueT>::get_value(*this, index);
 		}
 
+		void set_value(Value value, int index) override
+		{
+			if (index < 0 || index >= this->size())
+				throw runtime_error("Index out of bounds.");
+			return vector_value_helper<ValueT>::set_value(*this, value, index);
+		}
+
 		const PropertyClass *get_object(const int index) const override
 		{
 			return vector_value_helper<ValueT>::get_object(*this, index);

include/ki/serialization/JsonSerializer.h

@@ -30,6 +30,11 @@ namespace serialization
 		nlohmann::json save_object(const pclass::PropertyClass *object) const;
 		void save_property(nlohmann::json &j, const pclass::IProperty &prop) const;
 		void save_dynamic_property(nlohmann::json &j, const pclass::IDynamicProperty &prop) const;
+
+		virtual bool preload_object(std::unique_ptr<pclass::PropertyClass> &dest, nlohmann::json &j) const;
+		void load_object(std::unique_ptr<pclass::PropertyClass> &dest, nlohmann::json &j) const;
+		void load_property(pclass::IProperty &prop, nlohmann::json &j) const;
+		void load_dynamic_property(pclass::IDynamicProperty &prop, nlohmann::json &j) const;
 	};
 }
 }

src/pclass/Property.cpp

@@ -92,6 +92,12 @@ namespace pclass
 		throw runtime_error("Called get_value() on a dynamic property. Use get_value(index) instead.");
 	}
 
+	void IDynamicProperty::set_value(Value value)
+	{
+		// The caller must specify an index
+		throw runtime_error("Called set_value() on a dynamic property. Use set_value(index) instead.");
+	}
+
 	const PropertyClass *IDynamicProperty::get_object() const
 	{
 		// The caller must specify an index

src/pclass/Value.cpp

@@ -24,12 +24,23 @@ namespace pclass
 			m_deallocator = deallocator;
 		}
 
+		ValueDeallocator::ValueDeallocator(ValueDeallocator &that)
+		{
+			m_deallocator = that.m_deallocator->copy();
+		}
+
 		ValueDeallocator::ValueDeallocator(ValueDeallocator &&that) noexcept
 		{
 			m_deallocator = that.m_deallocator;
 			that.m_deallocator = nullptr;
 		}
 
+		ValueDeallocator &ValueDeallocator::operator=(ValueDeallocator &that)
+		{
+			m_deallocator = that.m_deallocator->copy();
+			return *this;
+		}
+
 		ValueDeallocator& ValueDeallocator::operator=(ValueDeallocator &&that) noexcept
 		{
 			m_deallocator = that.m_deallocator;
@@ -76,6 +87,15 @@ namespace pclass
 		m_deallocator = detail::ValueDeallocator();
 	}
 
+	Value::Value(Value& that)
+	{
+		m_value_ptr = that.m_value_ptr;
+		m_ptr_is_owned = false;
+		m_type_hash = that.m_type_hash;
+		m_caster = that.m_caster;
+		m_deallocator = that.m_deallocator;
+	}
+
 	Value::Value(Value &&that) noexcept
 	{
 		// Move pointer to this Value object, and take ownership if
@@ -88,6 +108,17 @@ namespace pclass
 		m_deallocator = std::move(that.m_deallocator);
 	}
 
+	Value &Value::operator=(Value &that)
+	{
+		m_value_ptr = that.m_value_ptr;
+		m_ptr_is_owned = false;
+		m_type_hash = that.m_type_hash;
+		m_caster = that.m_caster;
+		m_deallocator = that.m_deallocator;
+
+		return *this;
+	}
+
 	Value &Value::operator=(Value &&that) noexcept
 	{
 		// If the current pointer is owned, deallocate it

src/serialization/BinarySerializer.cpp

@@ -435,6 +435,5 @@ namespace serialization
 				prop.read_value_from(stream, i);
 		}
 	}
-
 }
 }

src/serialization/JsonSerializer.cpp

@@ -1,4 +1,5 @@
 #include "ki/serialization/JsonSerializer.h"
+#include <sstream>
 
 using namespace nlohmann;
 
@@ -54,7 +55,6 @@ namespace serialization
 	{
 		if (prop.is_dynamic())
 		{
-			// Cast the property to a IDynamicProperty
 			const auto &dynamic_property =
 				dynamic_cast<const pclass::IDynamicProperty &>(prop);
 			return save_dynamic_property(j, dynamic_property);
@@ -94,12 +94,108 @@ namespace serialization
 		j[prop.get_name()] = property_value;
 	}
 
-	void JsonSerializer::load(std::unique_ptr<pclass::PropertyClass>& dest, 
-		const std::string& json_string) const
+	void JsonSerializer::load(std::unique_ptr<pclass::PropertyClass> &dest,
+		const std::string &json_string) const
 	{
-		// TODO: JSON Deserialization
-		auto j = json::parse(json_string);
-		dest = nullptr;
+		try
+		{			
+			auto j = json::parse(json_string);
+			load_object(dest, j);
+		}
+		catch (json::exception &e)
+		{
+			std::ostringstream oss;
+			oss << "Failed to deserialize JSON - " << e.what();
+			throw runtime_error(oss.str());
+		}
+	}
+
+	bool JsonSerializer::preload_object(
+		std::unique_ptr<pclass::PropertyClass>& dest, json& j) const
+	{
+		// If meta information is not present, assume that the type hash is null.
+		if (!j.count("_pclass_meta"))
+			dest = nullptr;
+		else
+		{
+			// Use the type hash to instantiate an object
+			const auto type_hash = j["_pclass_meta"].value("type_hash", NULL);
+			if (type_hash != 0)
+			{
+				const auto &type = m_type_system->get_type(type_hash);
+				dest = type.instantiate();
+			}
+			else
+				dest = nullptr;
+		}
+		return dest != nullptr;
+	}
+
+	void JsonSerializer::load_object(
+		std::unique_ptr<pclass::PropertyClass> &dest, json &j) const
+	{
+		if (!preload_object(dest, j))
+			return;
+
+		auto &property_list = dest->get_properties();
+		for (auto it = property_list.begin();
+			it != property_list.end(); ++it)
+		{
+			auto &prop = *it;
+			load_property(prop, j);
+		}
+	}
+
+	void JsonSerializer::load_property(
+		pclass::IProperty &prop, json &j) const
+	{
+		if (!j.count(prop.get_name()))
+		{
+			std::ostringstream oss;
+			oss << "JSON object missing property: '" << prop.get_name() << "' "
+				<< "(type='" << prop.get_instance().get_type().get_name() << "').";
+			throw runtime_error(oss.str());
+		}
+
+		auto &property_j = j[prop.get_name()];
+		if (prop.is_dynamic())
+		{
+			auto &dynamic_property =
+				dynamic_cast<pclass::IDynamicProperty &>(prop);
+			return load_dynamic_property(dynamic_property, j);
+		}
+
+		if (prop.get_type().get_kind() == pclass::Type::kind::CLASS)
+		{
+			std::unique_ptr<pclass::PropertyClass> other_object = nullptr;
+			load_object(other_object, property_j);
+			prop.set_object(other_object);
+		}
+		else
+			prop.set_value(
+				pclass::Value::make_reference<json>(property_j)
+			);
+	}
+
+	void JsonSerializer::load_dynamic_property(
+		pclass::IDynamicProperty &prop, json &j) const
+	{
+		auto &property_j = j[prop.get_name()];
+		prop.set_element_count(property_j.size());
+
+		for (auto i = 0; i < prop.get_element_count(); ++i)
+		{
+			if (prop.get_type().get_kind() == pclass::Type::kind::CLASS)
+			{
+				std::unique_ptr<pclass::PropertyClass> other_object = nullptr;
+				load_object(other_object, property_j.at(i));
+				prop.set_object(other_object, i);
+			}
+			else
+				prop.set_value(
+					pclass::Value::make_reference<json>(property_j.at(i)), i
+				);
+		}
 	}
 }
 }

test/src/unit-serialization.cpp

@@ -108,7 +108,7 @@ namespace detail
 	struct value_caster<Vector3D, nlohmann::json>
 		: value_caster_impl<Vector3D, nlohmann::json>
 	{
-		nlohmann::json cast_value(const Vector3D &value) const
+		nlohmann::json cast_value(const Vector3D &value) const override
 		{
 			return {
 				{ "x", value.m_x },
@@ -125,7 +125,7 @@ namespace detail
 	struct value_caster<nlohmann::json, Vector3D>
 		: value_caster_impl<nlohmann::json, Vector3D>
 	{
-		Vector3D cast_value(const nlohmann::json &value) const
+		Vector3D cast_value(const nlohmann::json &value) const override
 		{
 			return Vector3D(
 				value["x"].get<float>(),
@@ -562,13 +562,11 @@ void test_serializer(
 		serializer.load(object, sample);
 
 		// Set test_object so that it is validated by the caller
-		/*
 		REQUIRE(object != nullptr);
 		test_object = std::unique_ptr<TestObject>(
 			dynamic_cast<TestObject *>(object.release())
 		);
 		REQUIRE(test_object != nullptr);
-		*/
 	}
 }