property_tree/detail/info_parser_write.hpp

0001 // ----------------------------------------------------------------------------
0002 // Copyright (C) 2002-2006 Marcin Kalicinski
0003 //
0004 // Distributed under the Boost Software License, Version 1.0.
0005 // (See accompanying file LICENSE_1_0.txt or copy at
0006 // http://www.boost.org/LICENSE_1_0.txt)
0007 //
0008 // For more information, see www.boost.org
0009 // ----------------------------------------------------------------------------
0010 #ifndef BOOST_PROPERTY_TREE_DETAIL_INFO_PARSER_WRITE_HPP_INCLUDED
0011 #define BOOST_PROPERTY_TREE_DETAIL_INFO_PARSER_WRITE_HPP_INCLUDED
0012
0013 #include "boost/property_tree/ptree.hpp"
0014 #include "boost/property_tree/detail/info_parser_utils.hpp"
0015 #include <string>
0016
0017 namespace boost { namespace property_tree { namespace info_parser
0018 {
0019     template<class Ch>
0020     void write_info_indent(std::basic_ostream<Ch> &stream,
0021           int indent,
0022           const info_writer_settings<Ch> &settings
0023           )
0024     {
0025         stream << std::basic_string<Ch>(indent * settings.indent_count, settings.indent_char);
0026     }
0027
0028     // Create necessary escape sequences from illegal characters
0029     template<class Ch>
0030     std::basic_string<Ch> create_escapes(const std::basic_string<Ch> &s)
0031     {
0032         std::basic_string<Ch> result;
0033         typename std::basic_string<Ch>::const_iterator b = s.begin();
0034         typename std::basic_string<Ch>::const_iterator e = s.end();
0035         while (b != e)
0036         {
0037             if (*b == Ch('\0')) result += Ch('\\'), result += Ch('0');
0038             else if (*b == Ch('\a')) result += Ch('\\'), result += Ch('a');
0039             else if (*b == Ch('\b')) result += Ch('\\'), result += Ch('b');
0040             else if (*b == Ch('\f')) result += Ch('\\'), result += Ch('f');
0041             else if (*b == Ch('\n')) result += Ch('\\'), result += Ch('n');
0042             else if (*b == Ch('\r')) result += Ch('\\'), result += Ch('r');
0043             else if (*b == Ch('\v')) result += Ch('\\'), result += Ch('v');
0044             else if (*b == Ch('"')) result += Ch('\\'), result += Ch('"');
0045             else if (*b == Ch('\\')) result += Ch('\\'), result += Ch('\\');
0046             else
0047                 result += *b;
0048             ++b;
0049         }
0050         return result;
0051     }
0052
0053     template<class Ch>
0054     bool is_simple_key(const std::basic_string<Ch> &key)
0055     {
0056         const static std::basic_string<Ch> chars = convert_chtype<Ch, char>(" \t{};\n\"");
0057         return !key.empty() && key.find_first_of(chars) == key.npos;
0058     }
0059
0060     template<class Ch>
0061     bool is_simple_data(const std::basic_string<Ch> &data)
0062     {
0063         const static std::basic_string<Ch> chars = convert_chtype<Ch, char>(" \t{};\n\"");
0064         return !data.empty() && data.find_first_of(chars) == data.npos;
0065     }
0066
0067     template<class Ptree>
0068     void write_info_helper(std::basic_ostream<typename Ptree::key_type::value_type> &stream,
0069                            const Ptree &pt,
0070                            int indent,
0071                            const info_writer_settings<typename Ptree::key_type::value_type> &settings)
0072     {
0073
0074         // Character type
0075         typedef typename Ptree::key_type::value_type Ch;
0076
0077         // Write data
0078         if (indent >= 0)
0079         {
0080             if (!pt.data().empty())
0081             {
0082                 std::basic_string<Ch> data = create_escapes(pt.template get_value<std::basic_string<Ch> >());
0083                 if (is_simple_data(data))
0084                     stream << Ch(' ') << data << Ch('\n');
0085                 else
0086                     stream << Ch(' ') << Ch('\"') << data << Ch('\"') << Ch('\n');
0087             }
0088             else if (pt.empty())
0089                 stream << Ch(' ') << Ch('\"') << Ch('\"') << Ch('\n');
0090             else
0091                 stream << Ch('\n');
0092         }
0093
0094         // Write keys
0095         if (!pt.empty())
0096         {
0097
0098             // Open brace
0099             if (indent >= 0)
0100             {
0101                 write_info_indent( stream, indent, settings);
0102                 stream << Ch('{') << Ch('\n');
0103             }
0104
0105             // Write keys
0106             typename Ptree::const_iterator it = pt.begin();
0107             for (; it != pt.end(); ++it)
0108             {
0109
0110                 // Output key
0111                 std::basic_string<Ch> key = create_escapes(it->first);
0112                 write_info_indent( stream, indent+1, settings);
0113                 if (is_simple_key(key))
0114                     stream << key;
0115                 else
0116                     stream << Ch('\"') << key << Ch('\"');
0117
0118                 // Output data and children
0119                 write_info_helper(stream, it->second, indent + 1, settings);
0120
0121             }
0122
0123             // Close brace
0124             if (indent >= 0)
0125             {
0126                 write_info_indent( stream, indent, settings);
0127                 stream << Ch('}') << Ch('\n');
0128             }
0129
0130         }
0131     }
0132
0133     // Write ptree to info stream
0134     template<class Ptree>
0135     void write_info_internal(std::basic_ostream<typename Ptree::key_type::value_type> &stream,
0136                              const Ptree &pt,
0137                              const std::string &filename,
0138                              const info_writer_settings<typename Ptree::key_type::value_type> &settings)
0139     {
0140         write_info_helper(stream, pt, -1, settings);
0141         stream.flush();
0142         if (!stream.good())
0143             BOOST_PROPERTY_TREE_THROW(info_parser_error("write error", filename, 0));
0144     }
0145
0146 } } }
0147
0148 #endif