~mailman-coders/mailman/2.1

# Copyright (C) 1998-2018 by the Free Software Foundation, Inc.

#

# This program is free software; you can redistribute it and/or

# modify it under the terms of the GNU General Public License

# as published by the Free Software Foundation; either version 2

# of the License, or (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.

"""A `safe' dictionary for string interpolation."""

from types import StringType

from UserDict import UserDict

COMMASPACE = ', '

class SafeDict(UserDict):

    """Dictionary which returns a default value for unknown keys.

    This is used in maketext so that editing templates is a bit more robust.

    """

    def __getitem__(self, key):

        try:

            return self.data[key]

        except KeyError:

            if isinstance(key, StringType):

                return '%('+key+')s'

            else:

                return '<Missing key: %s>' % `key`

    def interpolate(self, template):

        return template % self

class MsgSafeDict(SafeDict):

    def __init__(self, msg, dict=None):

        self.__msg = msg

        SafeDict.__init__(self, dict)

    def __getitem__(self, key):

        if key.startswith('msg_'):

            return self.__msg.get(key[4:], 'n/a')

        elif key.startswith('allmsg_'):

            missing = []

            all = self.__msg.get_all(key[7:], missing)

            if all is missing:

                return 'n/a'

            return COMMASPACE.join(all)

        else:

            return SafeDict.__getitem__(self, key)

    def copy(self):

        d = self.data.copy()

        for k in self.__msg.keys():

            vals = self.__msg.get_all(k)

            if len(vals) == 1:

                d['msg_'+k.lower()] = vals[0]

            else:

                d['allmsg_'+k.lower()] = COMMASPACE.join(vals)

        return d