poco/JSON/src/Query.cpp

//
// Query.cpp
//
// $Id$
//
// Library: JSON
// Package: JSON
// Module:  Query
//
// Copyright (c) 2012, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//

#include <sstream>

#include "Poco/StringTokenizer.h"
#include "Poco/RegularExpression.h"
#include "Poco/NumberParser.h"

#include "Poco/JSON/Query.h"


using Poco::Dynamic::Var;


namespace Poco {
namespace JSON {


Query::Query(const Var& source) : _source(source)
{

}


Query::~Query()
{
}


Object::Ptr Query::findObject(const std::string& path) const
{
	Object::Ptr obj;
	Var result = find(path);
	if ( result.type() == typeid(Object::Ptr) )
	{
		obj = result.extract<Object::Ptr>();
	}
	return obj;
}


Array::Ptr Query::findArray(const std::string& path) const
{
	Array::Ptr arr;
	Var result = find(path);
	if ( result.type() == typeid(Array::Ptr) )
	{
		arr = result.extract<Array::Ptr>();
	}
	return arr;
}


Var Query::find(const std::string& path) const
{
	Var result = _source;
	StringTokenizer tokenizer(path, ".");
	for(StringTokenizer::Iterator token = tokenizer.begin(); token != tokenizer.end(); token++)
	{
		if ( !result.isEmpty() )
		{
			std::vector<int> indexes;
			RegularExpression::MatchVec matches;
			int firstOffset = -1;
			int offset = 0;
			RegularExpression regex("\\[([0-9]+)\\]");
			while(regex.match(*token, offset, matches) > 0 )
			{
				if ( firstOffset == -1 )
				{
					firstOffset = static_cast<int>(matches[0].offset);
				}
				std::string num = token->substr(matches[1].offset, matches[1].length);
				indexes.push_back(NumberParser::parse(num));
				offset = static_cast<int>(matches[0].offset + matches[0].length);
			}

			std::string name(*token);
			if ( firstOffset != -1 )
			{
				name = name.substr(0, firstOffset);
			}

			if ( name.length() > 0 )
			{
				if ( result.type() == typeid(Object::Ptr) )
				{
					Object::Ptr o = result.extract<Object::Ptr>();
					result = o->get(name);
				}
			}

			if (    !result.isEmpty()
			        && !indexes.empty() )
			{
				for(std::vector<int>::iterator it = indexes.begin(); it != indexes.end(); ++it )
				{
					if ( result.type() == typeid(Array::Ptr) )
					{
						Array::Ptr array = result.extract<Array::Ptr>();
						result = array->get(*it);
						if ( result.isEmpty() )
						{
							break;
						}
					}
				}
			}
		}
	}
	return result;
}


}} // Namespace Poco::JSON