Chris@16: // ----------------------------------------------------------------------------
Chris@16: // Copyright (C) 2002-2006 Marcin Kalicinski
Chris@16: //
Chris@16: // Distributed under the Boost Software License, Version 1.0. 
Chris@16: // (See accompanying file LICENSE_1_0.txt or copy at 
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: //
Chris@16: // For more information, see www.boost.org
Chris@16: // ----------------------------------------------------------------------------
Chris@16: #ifndef BOOST_PROPERTY_TREE_DETAIL_JSON_PARSER_WRITE_HPP_INCLUDED
Chris@16: #define BOOST_PROPERTY_TREE_DETAIL_JSON_PARSER_WRITE_HPP_INCLUDED
Chris@16: 
Chris@16: #include <boost/property_tree/ptree.hpp>
Chris@16: #include <boost/next_prior.hpp>
Chris@16: #include <boost/type_traits/make_unsigned.hpp>
Chris@16: #include <string>
Chris@16: #include <ostream>
Chris@16: #include <iomanip>
Chris@16: 
Chris@16: namespace boost { namespace property_tree { namespace json_parser
Chris@16: {
Chris@16: 
Chris@16:     // Create necessary escape sequences from illegal characters
Chris@16:     template<class Ch>
Chris@16:     std::basic_string<Ch> create_escapes(const std::basic_string<Ch> &s)
Chris@16:     {
Chris@16:         std::basic_string<Ch> result;
Chris@16:         typename std::basic_string<Ch>::const_iterator b = s.begin();
Chris@16:         typename std::basic_string<Ch>::const_iterator e = s.end();
Chris@16:         while (b != e)
Chris@16:         {
Chris@101:             typedef typename make_unsigned<Ch>::type UCh;
Chris@101:             UCh c(*b);
Chris@16:             // This assumes an ASCII superset. But so does everything in PTree.
Chris@16:             // We escape everything outside ASCII, because this code can't
Chris@16:             // handle high unicode characters.
Chris@101:             if (c == 0x20 || c == 0x21 || (c >= 0x23 && c <= 0x2E) ||
Chris@101:                 (c >= 0x30 && c <= 0x5B) || (c >= 0x5D && c <= 0xFF))
Chris@16:                 result += *b;
Chris@16:             else if (*b == Ch('\b')) result += Ch('\\'), result += Ch('b');
Chris@16:             else if (*b == Ch('\f')) result += Ch('\\'), result += Ch('f');
Chris@16:             else if (*b == Ch('\n')) result += Ch('\\'), result += Ch('n');
Chris@16:             else if (*b == Ch('\r')) result += Ch('\\'), result += Ch('r');
Chris@101:             else if (*b == Ch('\t')) result += Ch('\\'), result += Ch('t');
Chris@16:             else if (*b == Ch('/')) result += Ch('\\'), result += Ch('/');
Chris@16:             else if (*b == Ch('"'))  result += Ch('\\'), result += Ch('"');
Chris@16:             else if (*b == Ch('\\')) result += Ch('\\'), result += Ch('\\');
Chris@16:             else
Chris@16:             {
Chris@16:                 const char *hexdigits = "0123456789ABCDEF";
Chris@16:                 unsigned long u = (std::min)(static_cast<unsigned long>(
Chris@16:                                                  static_cast<UCh>(*b)),
Chris@16:                                              0xFFFFul);
Chris@16:                 int d1 = u / 4096; u -= d1 * 4096;
Chris@16:                 int d2 = u / 256; u -= d2 * 256;
Chris@16:                 int d3 = u / 16; u -= d3 * 16;
Chris@16:                 int d4 = u;
Chris@16:                 result += Ch('\\'); result += Ch('u');
Chris@16:                 result += Ch(hexdigits[d1]); result += Ch(hexdigits[d2]);
Chris@16:                 result += Ch(hexdigits[d3]); result += Ch(hexdigits[d4]);
Chris@16:             }
Chris@16:             ++b;
Chris@16:         }
Chris@16:         return result;
Chris@16:     }
Chris@16: 
Chris@16:     template<class Ptree>
Chris@16:     void write_json_helper(std::basic_ostream<typename Ptree::key_type::value_type> &stream, 
Chris@16:                            const Ptree &pt,
Chris@16:                            int indent, bool pretty)
Chris@16:     {
Chris@16: 
Chris@16:         typedef typename Ptree::key_type::value_type Ch;
Chris@16:         typedef typename std::basic_string<Ch> Str;
Chris@16: 
Chris@16:         // Value or object or array
Chris@16:         if (indent > 0 && pt.empty())
Chris@16:         {
Chris@16:             // Write value
Chris@16:             Str data = create_escapes(pt.template get_value<Str>());
Chris@16:             stream << Ch('"') << data << Ch('"');
Chris@16: 
Chris@16:         }
Chris@16:         else if (indent > 0 && pt.count(Str()) == pt.size())
Chris@16:         {
Chris@16:             // Write array
Chris@16:             stream << Ch('[');
Chris@16:             if (pretty) stream << Ch('\n');
Chris@16:             typename Ptree::const_iterator it = pt.begin();
Chris@16:             for (; it != pt.end(); ++it)
Chris@16:             {
Chris@16:                 if (pretty) stream << Str(4 * (indent + 1), Ch(' '));
Chris@16:                 write_json_helper(stream, it->second, indent + 1, pretty);
Chris@16:                 if (boost::next(it) != pt.end())
Chris@16:                     stream << Ch(',');
Chris@16:                 if (pretty) stream << Ch('\n');
Chris@16:             }
Chris@101:             if (pretty) stream << Str(4 * indent, Ch(' '));
Chris@101:             stream << Ch(']');
Chris@16: 
Chris@16:         }
Chris@16:         else
Chris@16:         {
Chris@16:             // Write object
Chris@16:             stream << Ch('{');
Chris@16:             if (pretty) stream << Ch('\n');
Chris@16:             typename Ptree::const_iterator it = pt.begin();
Chris@16:             for (; it != pt.end(); ++it)
Chris@16:             {
Chris@16:                 if (pretty) stream << Str(4 * (indent + 1), Ch(' '));
Chris@16:                 stream << Ch('"') << create_escapes(it->first) << Ch('"') << Ch(':');
Chris@101:                 if (pretty) stream << Ch(' ');
Chris@16:                 write_json_helper(stream, it->second, indent + 1, pretty);
Chris@16:                 if (boost::next(it) != pt.end())
Chris@16:                     stream << Ch(',');
Chris@16:                 if (pretty) stream << Ch('\n');
Chris@16:             }
Chris@16:             if (pretty) stream << Str(4 * indent, Ch(' '));
Chris@16:             stream << Ch('}');
Chris@16:         }
Chris@16: 
Chris@16:     }
Chris@16: 
Chris@16:     // Verify if ptree does not contain information that cannot be written to json
Chris@16:     template<class Ptree>
Chris@16:     bool verify_json(const Ptree &pt, int depth)
Chris@16:     {
Chris@16: 
Chris@16:         typedef typename Ptree::key_type::value_type Ch;
Chris@16:         typedef typename std::basic_string<Ch> Str;
Chris@16: 
Chris@16:         // Root ptree cannot have data
Chris@16:         if (depth == 0 && !pt.template get_value<Str>().empty())
Chris@16:             return false;
Chris@16:         
Chris@16:         // Ptree cannot have both children and data
Chris@16:         if (!pt.template get_value<Str>().empty() && !pt.empty())
Chris@16:             return false;
Chris@16: 
Chris@16:         // Check children
Chris@16:         typename Ptree::const_iterator it = pt.begin();
Chris@16:         for (; it != pt.end(); ++it)
Chris@16:             if (!verify_json(it->second, depth + 1))
Chris@16:                 return false;
Chris@16: 
Chris@16:         // Success
Chris@16:         return true;
Chris@16: 
Chris@16:     }
Chris@16:     
Chris@16:     // Write ptree to json stream
Chris@16:     template<class Ptree>
Chris@16:     void write_json_internal(std::basic_ostream<typename Ptree::key_type::value_type> &stream, 
Chris@16:                              const Ptree &pt,
Chris@16:                              const std::string &filename,
Chris@16:                              bool pretty)
Chris@16:     {
Chris@16:         if (!verify_json(pt, 0))
Chris@16:             BOOST_PROPERTY_TREE_THROW(json_parser_error("ptree contains data that cannot be represented in JSON format", filename, 0));
Chris@16:         write_json_helper(stream, pt, 0, pretty);
Chris@16:         stream << std::endl;
Chris@16:         if (!stream.good())
Chris@16:             BOOST_PROPERTY_TREE_THROW(json_parser_error("write error", filename, 0));
Chris@16:     }
Chris@16: 
Chris@16: } } }
Chris@16: 
Chris@16: #endif