jansson/jansson-impl.hpp

// janssonxx - C++ wrapper for jansson, implementation file
//
// author: Sean Middleditch <sean@middleditch.us>
//
// janssonxx is free software; you can redistribute it and/or modify
// it under the terms of the MIT license. See LICENSE for details.

#if !defined(IN_JANSSON_HPP)
#	error "jansson-impl.hpp may only by included from jansson.hpp"
#endif

namespace json {
	namespace _private {
		// assignment operator
		template <typename _Base>
		ValueBase<_Base>& ValueBase<_Base>::operator=(const Value& value) {
			_Base::operator=(value);
			return *this;
		}

		// check value type
		template <typename _Base>
		bool ValueBase<_Base>::is_undefined() const {
			return _Base::as_json() == 0;
		}

		template <typename _Base>
		bool ValueBase<_Base>::is_object() const {
			return json_is_object(_Base::as_json());
		}

		template <typename _Base>
		bool ValueBase<_Base>::is_array() const {
			return json_is_array(_Base::as_json());
		}

		template <typename _Base>
		bool ValueBase<_Base>::is_string() const {
			return json_is_string(_Base::as_json());
		}

		template <typename _Base>
		bool ValueBase<_Base>::is_integer() const {
			return json_is_integer(_Base::as_json());
		}

		template <typename _Base>
		bool ValueBase<_Base>::is_real() const {
			return json_is_real(_Base::as_json());
		}

		template <typename _Base>
		bool ValueBase<_Base>::is_number() const {
			return json_is_number(_Base::as_json());
		}

		template <typename _Base>
		bool ValueBase<_Base>::is_true() const {
			return json_is_true(_Base::as_json());
		}

		template <typename _Base>
		bool ValueBase<_Base>::is_false() const {
			return json_is_false(_Base::as_json());
		}

		template <typename _Base>
		bool ValueBase<_Base>::is_boolean() const {
			return json_is_boolean(_Base::as_json());
		}

		template <typename _Base>
		bool ValueBase<_Base>::is_null() const {
			return json_is_null(_Base::as_json());
		}

		// get size of array or object
		template <typename _Base>
		unsigned int ValueBase<_Base>::size() const {
			if (is_object())
				return json_object_size(_Base::as_json());
			else
				return json_array_size(_Base::as_json());
		}

		// get value at array index (const version)
		template <typename _Base>
		const Value ValueBase<_Base>::at(unsigned int index) const {
			return Value(json_array_get(_Base::as_json(), index));
		}

		template <typename _Base>
		const Value ValueBase<_Base>::operator[](signed int index) const { return at(index); }
		template <typename _Base>
		const Value ValueBase<_Base>::operator[](unsigned int index) const { return at(index); }
		template <typename _Base>
		const Value ValueBase<_Base>::operator[](signed short index) const { return at(index); }
		template <typename _Base>
		const Value ValueBase<_Base>::operator[](unsigned short index) const { return at(index); }
		template <typename _Base>
		const Value ValueBase<_Base>::operator[](signed long index) const { return at(index); }
		template <typename _Base>
		const Value ValueBase<_Base>::operator[](unsigned long index) const { return at(index); }

		// get value at array index (non-const version)
		template <typename _Base>
		ValueBase<ElementProxy> ValueBase<_Base>::at(unsigned int index) {
			return ElementProxy(_Base::as_json(), index);
		}

		template <typename _Base>
		ValueBase<ElementProxy> ValueBase<_Base>::operator[](signed int index) {
			return at(index);
		}

		template <typename _Base>
		ValueBase<ElementProxy> ValueBase<_Base>::operator[](unsigned int index) {
			return at(index);
		}

		template <typename _Base>
		ValueBase<ElementProxy> ValueBase<_Base>::operator[](signed short index) {
			return at(index);
		}

		template <typename _Base>
		ValueBase<ElementProxy> ValueBase<_Base>::operator[](unsigned short index) {
			return at(index);
		}

		template <typename _Base>
		ValueBase<ElementProxy> ValueBase<_Base>::operator[](signed long index) {
			return at(index);
		}

		template <typename _Base>
		ValueBase<ElementProxy> ValueBase<_Base>::operator[](unsigned long index) {
			return at(index);
		}

		// get object property (const version)
		template <typename _Base>
		const Value ValueBase<_Base>::get(const char* key) const {
			return Value(json_object_get(_Base::as_json(), key));
		}

		template <typename _Base>
		const Value ValueBase<_Base>::get(const std::string& key) const {
			return get(key.c_str());
		}

		template <typename _Base>
		const Value ValueBase<_Base>::operator[](const char* key) const {
			return get(key);
		}

		template <typename _Base>
		const Value ValueBase<_Base>::operator[](const std::string& key) const {
			return get(key.c_str());
		}

		// get object property (non-const version)
		template <typename _Base>
		ValueBase<PropertyProxy> ValueBase<_Base>::get(const char* key) {
			return PropertyProxy(_Base::as_json(), key);
		}

		template <typename _Base>
		ValueBase<PropertyProxy> ValueBase<_Base>::get(const std::string& key) {
			return get(key.c_str());
		}

		template <typename _Base>
		ValueBase<PropertyProxy> ValueBase<_Base>::operator[](const char* key) {
			return get(key);
		}

		template <typename _Base>
		ValueBase<PropertyProxy> ValueBase<_Base>::operator[](const std::string& key) {
			return get(key.c_str());
		}

		// clear all array/object values
		template <typename _Base>
		void ValueBase<_Base>::clear() {
			if (is_object())
				json_object_clear(_Base::as_json());
			else
				json_array_clear(_Base::as_json());
		}

		// get value cast to specified type
		template <typename _Base>
		const char* ValueBase<_Base>::as_cstring() const {
			return json_string_value(_Base::as_json());
		}

		template <typename _Base>
		std::string ValueBase<_Base>::as_string() const {
			const char* tmp = as_cstring();
			return tmp == 0 ? "" : tmp;
		}

		template <typename _Base>
		int ValueBase<_Base>::as_integer() const {
			return json_integer_value(_Base::as_json());
		}

		template <typename _Base>
		double ValueBase<_Base>::as_real() const {
			return json_real_value(_Base::as_json());
		}

		template <typename _Base>
		double ValueBase<_Base>::as_number() const {
			return json_number_value(_Base::as_json());
		}

		template <typename _Base>
		bool ValueBase<_Base>::as_boolean() const {
			return is_true();
		}

		// set an object property (converts value to object is not one already)
		template <typename _Base>
		_Base& ValueBase<_Base>::set_key(const char* key, const Value& value) {
			json_object_set(_Base::as_json(), key, value._Base::as_json());
			return *this;
		}

		template <typename _Base>
		_Base& ValueBase<_Base>::set_key(const std::string& key, const Value& value) {
			return set_key(key.c_str(), value);
		}

		// set an array index (converts value to object is not one already)
		template <typename _Base>
		_Base& ValueBase<_Base>::set_at(unsigned int index, const Value& value) {
			if (index == size())
				json_array_append(_Base::as_json(), value._Base::as_json());
			else
				json_array_set(_Base::as_json(), index, value._Base::as_json());
			return *this;
		}

		// delete an object key
		template <typename _Base>
		_Base& ValueBase<_Base>::del_key(const char* key) {
			json_object_del(_Base::as_json(), key);
			return *this;
		}

		template <typename _Base>
		_Base& ValueBase<_Base>::del_key(const std::string& key) {
			return del_key(key.c_str());
		}

		// delete an item from an array by index
		template <typename _Base>
		_Base& ValueBase<_Base>::del_at(unsigned int index) {
			json_array_remove(_Base::as_json(), index);
			return *this;
		}

		// insert an item into an array at a given index
		template <typename _Base>
		_Base& ValueBase<_Base>::insert_at(unsigned int index, const Value& value) {
			json_array_insert(_Base::as_json(), index, value._Base::as_json());
			return *this;
		}

		// write the value to a file
		template <typename _Base>
		int ValueBase<_Base>::save_file(const char* path, int flags) const {
			return json_dump_file(_Base::as_json(), path, flags);
		}

		// write the value to a string (caller must deallocate with free()!)
		template <typename _Base>
		char* ValueBase<_Base>::save_string(int flags) const {
			return json_dumps(_Base::as_json(), flags);
		}

		Basic::~Basic() {
			json_decref(_value);
		}

		// copy an existing Value
		Basic& Basic::operator=(const Basic& e) {
			if (&e != this) {
				json_decref(_value);
				_value = json_incref(e._value);
			}
			return *this;
		}

		// get the underlying json_t
		json_t* Basic::as_json() const {
			return _value;
		}

		// take ownership of a json_t (does not increase reference count)
		Basic Basic::take_ownership(json_t* json) {
			Basic v;
			v._value = json;
			return v;
		}

		// assign value to proxied array element
		ElementProxy& ElementProxy::operator=(const Value& value) {
			json_array_set(_array, _index, value.as_json());
			return *this;
		}

		// get the proxied element
		json_t* ElementProxy::as_json() const {
			return json_array_get(_array, _index);
		}

		// assign value to proxied object property
		PropertyProxy& PropertyProxy::operator=(const Value& value) {
			json_object_set(_object, _key, value.as_json());
			return *this;
		}

		json_t* PropertyProxy::as_json() const {
			return json_object_get(_object, _key);
		}

	} // namespace json::_private
	
	// construct a new iterator for a given object
	Iterator::Iterator(const Value& value) : _object(value), _iter(0) {
		_iter = json_object_iter(_object.as_json());
	}

	// construct a new iterator for a given object
	Iterator::Iterator(const _private::ValueBase<_private::PropertyProxy>& value) :
			_object(value.as_json()), _iter(0) {
		_iter = json_object_iter(_object.as_json());
	}

	// increment iterator
	void Iterator::next() {
		_iter = json_object_iter_next(_object.as_json(), _iter);
	}

	Iterator& Iterator::operator++() { next(); return *this; }

	// test if iterator is still valid
	bool Iterator::valid() const {
		return _iter != 0;
	}

	Iterator::operator bool() const {
		return valid();
	}

	// get key
	const char* Iterator::ckey() const {
		return json_object_iter_key(_iter);
	}

	std::string Iterator::key() const {
		return ckey();
	}

	// get value
	const Value Iterator::value() const {
		return Value(json_object_iter_value(_iter));
	}

	// dereference value
	const Value Iterator::operator*() const {
		return value();
	}

	// construct Value from input
	Value from(const char* value) {
		return Value::take_ownership(json_string(value));
	}

	Value from(const std::string& value) {
		return from(value.c_str());
	}

	Value from(bool value) {
		return Value::take_ownership(value ? json_true() : json_false());
	}

	Value from(signed int value) {
		return Value::take_ownership(json_integer(value));
	}

	Value from(unsigned int value) {
		return Value::take_ownership(json_integer(value));
	}

	Value from(signed short value) {
		return Value::take_ownership(json_integer(value));
	}

	Value from(unsigned short value) {
		return Value::take_ownership(json_integer(value));
	}

	Value from(signed long value) {
		return Value::take_ownership(json_integer(value));
	}

	Value from(unsigned long value) {
		return Value::take_ownership(json_integer(value));
	}

	Value from(float value) {
		return Value::take_ownership(json_real(value));
	}

	Value from(double value) {
		return Value::take_ownership(json_real(value));
	}

	// create a new empty object
	Value object() {
		return Value::take_ownership(json_object());
	}

	// create a new empty array
	Value array() {
		return Value::take_ownership(json_array());
	}

	// create a new null value
	Value null() {
		return Value::take_ownership(json_null());
	}

	// load a file as a JSON value
	Value load_file(const char* path, json_error_t* error) {
		return Value::take_ownership(json_load_file(path, error));
	}

	// load a string as a JSON value
	Value load_string(const char* string, json_error_t* error) {
		return Value::take_ownership(json_loads(string, error));
	}

} // namespace json

// stream JSON value out
std::ostream& operator<<(std::ostream& os, const json::Value& value) {
	// get the temporary serialize string
	char* tmp = value.save_string();
	if (tmp != 0) {
		// stream temp string out and release it
		os << tmp;
		free(tmp);
	}
	return os;
}

// read JSON value
std::istream& operator>>(std::istream& is, json::Value& value) {
	// buffer the remaining bytes into a single string for Jansson
	std::stringstream tmp;
	while (is)
		tmp << static_cast<char>(is.get());
	// parse the buffered string
	value = json::load_string(tmp.str().c_str());
	return is;
}