boost/date_time/strings_from_facet.hpp

   1 #ifndef DATE_TIME_STRINGS_FROM_FACET__HPP___
   2 #define DATE_TIME_STRINGS_FROM_FACET__HPP___
   3
   4 /* Copyright (c) 2004 CrystalClear Software, Inc.
   5  * Use, modification and distribution is subject to the
   6  * Boost Software License, Version 1.0. (See accompanying
   7  * file LICENSE_1_0.txt or http://www.boost.org/LICENSE_1_0.txt)
   8  * Author: Jeff Garland
   9  * $Date$
  10  */
  11
  12 #include <sstream>
  13 #include <string>
  14 #include <vector>
  15 #include <locale>
  16
  17 namespace boost { namespace date_time {
  18
  19 //! This function gathers up all the month strings from a std::locale
  20 /*! Using the time_put facet, this function creates a collection of
  21  *  all the month strings from a locale.  This is handy when building
  22  *  custom date parsers or formatters that need to be localized.
  23  *
  24  *@param charT The type of char to use when gathering typically char
  25  *             or wchar_t.
  26  *@param locale The locale to use when gathering the strings
  27  *@param short_strings True(default) to gather short strings,
  28  *                     false for long strings.
  29  *@return A vector of strings containing the strings in order. eg:
  30  *        Jan, Feb, Mar, etc.
  31  */
  32 template<typename charT>
  33 std::vector<std::basic_string<charT> >
  34 gather_month_strings(const std::locale& locale, bool short_strings=true)
  35 {
  36   typedef std::basic_string<charT> string_type;
  37   typedef std::vector<string_type> collection_type;
  38   typedef std::basic_ostringstream<charT> ostream_type;
  39   typedef std::ostreambuf_iterator<charT> ostream_iter_type;
  40   typedef std::basic_ostringstream<charT> stringstream_type;
  41   typedef std::time_put<charT>           time_put_facet_type;
  42   charT short_fmt[3] = { '%', 'b' };
  43   charT long_fmt[3]  = { '%', 'B' };
  44   collection_type months;
  45   string_type outfmt(short_fmt);
  46   if (!short_strings) {
  47     outfmt = long_fmt;
  48   }
  49   {
  50     //grab the needed strings by using the locale to
  51     //output each month
  52     const charT* p_outfmt = outfmt.c_str(), *p_outfmt_end = p_outfmt + outfmt.size();
  53     for (int m=0; m < 12; m++) {
  54       tm tm_value;
  55       tm_value.tm_mon = m;
  56       stringstream_type ss;
  57       ostream_iter_type oitr(ss);
  58       std::use_facet<time_put_facet_type>(locale).put(oitr, ss, ss.fill(),
  59                                                       &tm_value,
  60                                                       p_outfmt,
  61                                                       p_outfmt_end);
  62       months.push_back(ss.str());
  63     }
  64   }
  65   return months;
  66 }
  67
  68 //! This function gathers up all the weekday strings from a std::locale
  69 /*! Using the time_put facet, this function creates a collection of
  70  *  all the weekday strings from a locale starting with the string for
  71  *  'Sunday'.  This is handy when building custom date parsers or
  72  *  formatters that need to be localized.
  73  *
  74  *@param charT The type of char to use when gathering typically char
  75  *             or wchar_t.
  76  *@param locale The locale to use when gathering the strings
  77  *@param short_strings True(default) to gather short strings,
  78  *                     false for long strings.
  79  *@return A vector of strings containing the weekdays in order. eg:
  80  *        Sun, Mon, Tue, Wed, Thu, Fri, Sat
  81  */
  82 template<typename charT>
  83 std::vector<std::basic_string<charT> >
  84 gather_weekday_strings(const std::locale& locale, bool short_strings=true)
  85 {
  86   typedef std::basic_string<charT> string_type;
  87   typedef std::vector<string_type> collection_type;
  88   typedef std::basic_ostringstream<charT> ostream_type;
  89   typedef std::ostreambuf_iterator<charT> ostream_iter_type;
  90   typedef std::basic_ostringstream<charT> stringstream_type;
  91   typedef std::time_put<charT>           time_put_facet_type;
  92   charT short_fmt[3] = { '%', 'a' };
  93   charT long_fmt[3]  = { '%', 'A' };
  94
  95   collection_type weekdays;
  96
  97
  98   string_type outfmt(short_fmt);
  99   if (!short_strings) {
 100     outfmt = long_fmt;
 101   }
 102   {
 103     //grab the needed strings by using the locale to
 104     //output each month / weekday
 105     const charT* p_outfmt = outfmt.c_str(), *p_outfmt_end = p_outfmt + outfmt.size();
 106     for (int i=0; i < 7; i++) {
 107       tm tm_value;
 108       tm_value.tm_wday = i;
 109       stringstream_type ss;
 110       ostream_iter_type oitr(ss);
 111       std::use_facet<time_put_facet_type>(locale).put(oitr, ss, ss.fill(),
 112                                                       &tm_value,
 113                                                       p_outfmt,
 114                                                       p_outfmt_end);
 115
 116       weekdays.push_back(ss.str());
 117     }
 118   }
 119   return weekdays;
 120 }
 121
 122 } } //namespace
 123
 124
 125 #endif