mailman/SafeDict.py

   1 # Copyright (C) 1998-2008 by the Free Software Foundation, Inc.
   2 #
   3 # This program is free software; you can redistribute it and/or
   4 # modify it under the terms of the GNU General Public License
   5 # as published by the Free Software Foundation; either version 2
   6 # of the License, or (at your option) any later version.
   7 #
   8 # This program is distributed in the hope that it will be useful,
   9 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 # GNU General Public License for more details.
  12 #
  13 # You should have received a copy of the GNU General Public License
  14 # along with this program; if not, write to the Free Software
  15 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  16 # USA.
  17
  18 from mailman.configuration import config
  19
  20 """A `safe' dictionary for string interpolation."""
  21
  22 COMMASPACE = ', '
  23
  24 # XXX This module should go away.
  25
  26
  27 \f
  28 class SafeDict(dict):
  29     """Dictionary which returns a default value for unknown keys.
  30
  31     This is used in maketext so that editing templates is a bit more robust.
  32     """
  33     def __init__(self, d='', charset=None, lang=None):
  34         super(SafeDict, self).__init__(d)
  35         if charset:
  36             self.cset = charset
  37         elif lang:
  38             self.cset = config.languages.get_charset(lang)
  39         else:
  40             self.cset = 'us-ascii'
  41
  42     def __getitem__(self, key):
  43         try:
  44             return super(SafeDict, self).__getitem__(key)
  45         except KeyError:
  46             if isinstance(key, basestring):
  47                 return '%('+key+')s'
  48             else:
  49                 return '<Missing key: %s>' % `key`
  50
  51     def interpolate(self, template):
  52         for k, v in self.items():
  53             if isinstance(v, str):
  54                 self.__setitem__(k, unicode(v, self.cset))
  55         return template % self