~ubuntu-core-dev/ubuntu-release-upgrader/trunk

# DistUpgradeGettext.py - safe wrapper around gettext

#  

#  Copyright (c) 2008 Canonical

#  

#  Author: Michael Vogt <michael.vogt@ubuntu.com>

# 

#  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., 59 Temple Place, Suite 330, Boston, MA 02111-1307

#  USA

import logging

import gettext as mygettext

_gettext_method = "gettext"

_ngettext_method = "ngettext"

def _verify(message, translated):

    """ 

    helper that verifies that the message and the translated 

    message have the same number (and type) of % args

    """

    arguments_in_message = message.count("%") - message.count("\%")

    arguments_in_translation = translated.count("%") - translated.count("\%")

    return arguments_in_message == arguments_in_translation

_translation_singleton = None

def _translation():

    """Return a suitable gettext.*Translations instance."""

    global _translation_singleton

    if _translation_singleton is None:

        domain = mygettext.textdomain()

        _translation_singleton = mygettext.translation(

            domain, mygettext.bindtextdomain(domain), fallback=True)

    return _translation_singleton

def unicode_gettext(translation, message):

    return getattr(translation, _gettext_method)(message)

def unicode_ngettext(translation, singular, plural, n):

    return getattr(translation, _ngettext_method)(singular, plural, n)

def gettext(message):

    """

    version of gettext that logs errors but does not crash on incorrect

    number of arguments

    """

    if message == "":

        return ""

    translated_msg = unicode_gettext(_translation(), message)

    if not _verify(message, translated_msg):

        logging.error(

            "incorrect translation for message '%s' to '%s' "

            "(wrong number of arguments)" % (message, translated_msg))

        return message

    return translated_msg

def ngettext(msgid1, msgid2, n):

    """

    version of ngettext that logs errors but does not crash on incorrect

    number of arguments

    """

    translated_msg = unicode_ngettext(_translation(), msgid1, msgid2, n)

    if not _verify(msgid1, translated_msg):

        logging.error(

            "incorrect translation for ngettext message "

            "'%s' plural: '%s' to '%s' (wrong number of arguments)" % (

                msgid1, msgid2, translated_msg))

        # dumb fallback to not crash

        if n == 1:

            return msgid1

        return msgid2

    return translated_msg