boost/property_tree/detail/info_parser_write.hpp

   1 // ----------------------------------------------------------------------------
   2 // Copyright (C) 2002-2006 Marcin Kalicinski
   3 //
   4 // Distributed under the Boost Software License, Version 1.0.
   5 // (See accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt)
   7 //
   8 // For more information, see www.boost.org
   9 // ----------------------------------------------------------------------------
  10 #ifndef BOOST_PROPERTY_TREE_DETAIL_INFO_PARSER_WRITE_HPP_INCLUDED
  11 #define BOOST_PROPERTY_TREE_DETAIL_INFO_PARSER_WRITE_HPP_INCLUDED
  12
  13 #include "boost/property_tree/ptree.hpp"
  14 #include "boost/property_tree/detail/info_parser_utils.hpp"
  15 #include <string>
  16
  17 namespace boost { namespace property_tree { namespace info_parser
  18 {
  19     template<class Ch>
  20     void write_info_indent(std::basic_ostream<Ch> &stream,
  21           int indent,
  22           const info_writer_settings<Ch> &settings
  23           )
  24     {
  25         stream << std::basic_string<Ch>(indent * settings.indent_count, settings.indent_char);
  26     }
  27
  28     // Create necessary escape sequences from illegal characters
  29     template<class Ch>
  30     std::basic_string<Ch> create_escapes(const std::basic_string<Ch> &s)
  31     {
  32         std::basic_string<Ch> result;
  33         typename std::basic_string<Ch>::const_iterator b = s.begin();
  34         typename std::basic_string<Ch>::const_iterator e = s.end();
  35         while (b != e)
  36         {
  37             if (*b == Ch('\0')) result += Ch('\\'), result += Ch('0');
  38             else if (*b == Ch('\a')) result += Ch('\\'), result += Ch('a');
  39             else if (*b == Ch('\b')) result += Ch('\\'), result += Ch('b');
  40             else if (*b == Ch('\f')) result += Ch('\\'), result += Ch('f');
  41             else if (*b == Ch('\n')) result += Ch('\\'), result += Ch('n');
  42             else if (*b == Ch('\r')) result += Ch('\\'), result += Ch('r');
  43             else if (*b == Ch('\v')) result += Ch('\\'), result += Ch('v');
  44             else if (*b == Ch('"')) result += Ch('\\'), result += Ch('"');
  45             else if (*b == Ch('\\')) result += Ch('\\'), result += Ch('\\');
  46             else
  47                 result += *b;
  48             ++b;
  49         }
  50         return result;
  51     }
  52
  53     template<class Ch>
  54     bool is_simple_key(const std::basic_string<Ch> &key)
  55     {
  56         const static std::basic_string<Ch> chars = convert_chtype<Ch, char>(" \t{};\n\"");
  57         return !key.empty() && key.find_first_of(chars) == key.npos;
  58     }
  59
  60     template<class Ch>
  61     bool is_simple_data(const std::basic_string<Ch> &data)
  62     {
  63         const static std::basic_string<Ch> chars = convert_chtype<Ch, char>(" \t{};\n\"");
  64         return !data.empty() && data.find_first_of(chars) == data.npos;
  65     }
  66
  67     template<class Ptree>
  68     void write_info_helper(std::basic_ostream<typename Ptree::key_type::value_type> &stream,
  69                            const Ptree &pt,
  70                            int indent,
  71                            const info_writer_settings<typename Ptree::key_type::value_type> &settings)
  72     {
  73
  74         // Character type
  75         typedef typename Ptree::key_type::value_type Ch;
  76
  77         // Write data
  78         if (indent >= 0)
  79         {
  80             if (!pt.data().empty())
  81             {
  82                 std::basic_string<Ch> data = create_escapes(pt.template get_value<std::basic_string<Ch> >());
  83                 if (is_simple_data(data))
  84                     stream << Ch(' ') << data << Ch('\n');
  85                 else
  86                     stream << Ch(' ') << Ch('\"') << data << Ch('\"') << Ch('\n');
  87             }
  88             else if (pt.empty())
  89                 stream << Ch(' ') << Ch('\"') << Ch('\"') << Ch('\n');
  90             else
  91                 stream << Ch('\n');
  92         }
  93
  94         // Write keys
  95         if (!pt.empty())
  96         {
  97
  98             // Open brace
  99             if (indent >= 0)
 100             {
 101                 write_info_indent( stream, indent, settings);
 102                 stream << Ch('{') << Ch('\n');
 103             }
 104
 105             // Write keys
 106             typename Ptree::const_iterator it = pt.begin();
 107             for (; it != pt.end(); ++it)
 108             {
 109
 110                 // Output key
 111                 std::basic_string<Ch> key = create_escapes(it->first);
 112                 write_info_indent( stream, indent+1, settings);
 113                 if (is_simple_key(key))
 114                     stream << key;
 115                 else
 116                     stream << Ch('\"') << key << Ch('\"');
 117
 118                 // Output data and children
 119                 write_info_helper(stream, it->second, indent + 1, settings);
 120
 121             }
 122
 123             // Close brace
 124             if (indent >= 0)
 125             {
 126                 write_info_indent( stream, indent, settings);
 127                 stream << Ch('}') << Ch('\n');
 128             }
 129
 130         }
 131     }
 132
 133     // Write ptree to info stream
 134     template<class Ptree>
 135     void write_info_internal(std::basic_ostream<typename Ptree::key_type::value_type> &stream,
 136                              const Ptree &pt,
 137                              const std::string &filename,
 138                              const info_writer_settings<typename Ptree::key_type::value_type> &settings)
 139     {
 140         write_info_helper(stream, pt, -1, settings);
 141         if (!stream.good())
 142             BOOST_PROPERTY_TREE_THROW(info_parser_error("write error", filename, 0));
 143     }
 144
 145 } } }
 146
 147 #endif