mediagoblin/tools/translate.py

   1 # GNU MediaGoblin -- federated, autonomous media hosting
   2 # Copyright (C) 2011, 2012 MediaGoblin contributors.  See AUTHORS.
   3 #
   4 # This program is free software: you can redistribute it and/or modify
   5 # it under the terms of the GNU Affero General Public License as published by
   6 # the Free Software Foundation, either version 3 of the License, or
   7 # (at your option) any later version.
   8 #
   9 # This program is distributed in the hope that it will be useful,
  10 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 # GNU Affero General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU Affero General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16
  17 import gettext
  18 import pkg_resources
  19
  20
  21 from babel import localedata
  22 from babel.support import LazyProxy
  23
  24 from mediagoblin import mg_globals
  25
  26 ###################
  27 # Translation tools
  28 ###################
  29
  30 AVAILABLE_LOCALES = None
  31 TRANSLATIONS_PATH = pkg_resources.resource_filename(
  32     'mediagoblin', 'i18n')
  33
  34
  35 def set_available_locales():
  36     """Set available locales for which we have translations"""
  37     global AVAILABLE_LOCALES
  38     locales=['en', 'en_US'] # these are available without translations
  39     for locale in localedata.list():
  40         if gettext.find('mediagoblin', TRANSLATIONS_PATH, [locale]):
  41             locales.append(locale)
  42     AVAILABLE_LOCALES = locales
  43
  44
  45 def locale_to_lower_upper(locale):
  46     """
  47     Take a locale, regardless of style, and format it like "en_US"
  48     """
  49     if '-' in locale:
  50         lang, country = locale.split('-', 1)
  51         return '%s_%s' % (lang.lower(), country.upper())
  52     elif '_' in locale:
  53         lang, country = locale.split('_', 1)
  54         return '%s_%s' % (lang.lower(), country.upper())
  55     else:
  56         return locale.lower()
  57
  58
  59 def locale_to_lower_lower(locale):
  60     """
  61     Take a locale, regardless of style, and format it like "en_us"
  62     """
  63     if '_' in locale:
  64         lang, country = locale.split('_', 1)
  65         return '%s-%s' % (lang.lower(), country.lower())
  66     else:
  67         return locale.lower()
  68
  69
  70 def get_locale_from_request(request):
  71     """
  72     Return most appropriate language based on prefs/request request
  73     """
  74     request_args = (request.args, request.form)[request.method=='POST']
  75
  76     if 'lang' in request_args:
  77         # User explicitely demanded a language, normalize lower_uppercase
  78         target_lang = locale_to_lower_upper(request_args['lang'])
  79
  80     elif 'target_lang' in request.session:
  81         # TODO: Uh, ohh, this is never ever set anywhere?
  82         target_lang = request.session['target_lang']
  83     else:
  84         # Pull the most acceptable language based on browser preferences
  85         # This returns one of AVAILABLE_LOCALES which is aready case-normalized.
  86         # Note: in our tests request.accept_languages is None, so we need
  87         # to explicitely fallback to en here.
  88         target_lang = request.accept_languages.best_match(AVAILABLE_LOCALES) \
  89                       or "en_US"
  90
  91     return target_lang
  92
  93 SETUP_GETTEXTS = {}
  94
  95 def get_gettext_translation(locale):
  96     """
  97     Return the gettext instance based on this locale
  98     """
  99     # Later on when we have plugins we may want to enable the
 100     # multi-translations system they have so we can handle plugin
 101     # translations too
 102
 103     # TODO: fallback nicely on translations from pt_PT to pt if not
 104     # available, etc.
 105     if locale in SETUP_GETTEXTS:
 106         this_gettext = SETUP_GETTEXTS[locale]
 107     else:
 108         this_gettext = gettext.translation(
 109             'mediagoblin', TRANSLATIONS_PATH, [locale], fallback=True)
 110         if localedata.exists(locale):
 111             SETUP_GETTEXTS[locale] = this_gettext
 112     return this_gettext
 113
 114
 115 def pass_to_ugettext(*args, **kwargs):
 116     """
 117     Pass a translation on to the appropriate ugettext method.
 118
 119     The reason we can't have a global ugettext method is because
 120     mg_globals gets swapped out by the application per-request.
 121     """
 122     return mg_globals.thread_scope.translations.ugettext(
 123         *args, **kwargs)
 124
 125
 126 def lazy_pass_to_ugettext(*args, **kwargs):
 127     """
 128     Lazily pass to ugettext.
 129
 130     This is useful if you have to define a translation on a module
 131     level but you need it to not translate until the time that it's
 132     used as a string. For example, in:
 133         def func(self, message=_('Hello boys and girls'))
 134
 135     you would want to use the lazy version for _.
 136     """
 137     return LazyProxy(pass_to_ugettext, *args, **kwargs)
 138
 139
 140 def pass_to_ngettext(*args, **kwargs):
 141     """
 142     Pass a translation on to the appropriate ngettext method.
 143
 144     The reason we can't have a global ngettext method is because
 145     mg_globals gets swapped out by the application per-request.
 146     """
 147     return mg_globals.thread_scope.translations.ngettext(
 148         *args, **kwargs)
 149
 150
 151 def lazy_pass_to_ngettext(*args, **kwargs):
 152     """
 153     Lazily pass to ngettext.
 154
 155     This is useful if you have to define a translation on a module
 156     level but you need it to not translate until the time that it's
 157     used as a string.
 158     """
 159     return LazyProxy(pass_to_ngettext, *args, **kwargs)
 160
 161
 162 def fake_ugettext_passthrough(string):
 163     """
 164     Fake a ugettext call for extraction's sake ;)
 165
 166     In wtforms there's a separate way to define a method to translate
 167     things... so we just need to mark up the text so that it can be
 168     extracted, not so that it's actually run through gettext.
 169     """
 170     return string