Source code for abilian.i18n

# coding=utf-8
"""
I18n.

To mark strings for transalation::

    from abilian.i18n import _
    _(u'message to translate')

Use :data:`_` for gettext, :data:`_l` for lazy_gettext, :data:`_n` for
ngettext.

:data:`Babel extension<babel>` support multiple translation paths. This
allows to add more catalogs to search for translations, in LIFO
order. This feature can be used to override some translations in a
custom application, be providing a catalog with messages to override::

    current_app.extensions['babel'].add_translations('abilian.core')

See :meth:`add_translations<Babel.add_translations>`.

To extract messages to build the message catalog template (.pot), use the
following "`-k`" parameters:

.. code-block:: bash

    $ pybabel extract -F babel.cfg -k "_n:1,2" -k "_l" -o "msg.pot" "src"


This can be made easier by placing in `setup.cfg`:

.. code-block:: ini

    [extract_messages]
    mapping_file = babel.cfg
    keywords = _n:1,2 _l
    output-file = msg.pot
    input-dirs = src


And just type:

.. code-block:: bash

    $ python setup.py extract_messages


"""
from __future__ import absolute_import, print_function, division

import os
import re
import importlib
import unicodedata
from pathlib import Path
from contextlib import contextmanager
from datetime import datetime

import pytz
from babel import Locale
from babel.localedata import locale_identifiers
from babel.support import Translations
from babel.dates import LOCALTZ, get_timezone, get_timezone_gmt
from flask import g, request, _request_ctx_stack, current_app, render_template
import flask_babel
from flask_babel import (
    Babel as BabelBase,
    gettext, lazy_gettext, ngettext,
)

__all__ = [
  'babel',
  'gettext', '_',
  'lazy_gettext', '_l', 'localeselector',
  'ngettext', '_n',
  'set_locale',
  'timezoneselector',
  'VALID_LANGUAGES_CODE',
  'render_template_i18n'
]

#: gettext alias
_ = gettext

#: lazy_gettext alias
_l = lazy_gettext
#: ngettext alias
_n = ngettext

#: accepted languages codes
VALID_LANGUAGES_CODE = frozenset(lang for lang in locale_identifiers()
                                 if len(lang) == 2)

def get_default_locale():
  return current_app.extensions['babel'].default_locale


def _get_locale():
  locale = flask_babel.get_locale()
  if locale is None:
    locale = get_default_locale()
  return locale


def __gettext_territory(code):
  locale = _get_locale()
  return (
      locale.territories.get(code)
      or get_default_locale().territories.get(code))

#: get localized territory name
def country_name(code):
  return __gettext_territory(code)

#: lazy version of :func:`country_name`
def lazy_country_name(code):
  from speaklater import make_lazy_string
  return make_lazy_string(__gettext_territory, code)


def default_country():
  return current_app.config.get('DEFAULT_COUNTRY')


def country_choices(first=None, default_country_first=True):
  """
  Return a list of (code, countries), alphabetically sorted on localized
  country name.

  :param first: Country code to be placed at the top
  """
  locale = _get_locale()
  territories = [(code, name) for code, name in locale.territories.iteritems()
                 if len(code) == 2] # skip 3-digit regions

  if first is None and default_country_first:
    first = default_country()

  def sortkey(item):
    if first is not None and item[0] == first:
      return u'0'
    return to_lower_ascii(item[1])

  territories.sort(key=sortkey)
  return territories


def supported_app_locales():
  """
  language codes and labels supported by current application

  :return: an iterable of `(:class:`babel.Locale`, label)`, label being the
  locale language human name in current locale.
  """
  locale = _get_locale()
  codes = current_app.config['BABEL_ACCEPT_LANGUAGES']
  return ((Locale.parse(code), locale.languages.get(code, code))
          for code in codes)


def timezones_choices():
  """
  Timezones values and their labels for current locale.

  :return: an iterable of `(code, label)`, code being a timezone code and label
  the timezone name in current locale.
  """
  utcnow = pytz.utc.localize(datetime.utcnow())
  locale = _get_locale()
  for tz in sorted(pytz.common_timezones):
    tz = get_timezone(tz)
    now = tz.normalize(utcnow.astimezone(tz))
    label = u'({}) {}'.format(get_timezone_gmt(now, locale=locale), tz.zone)
    yield (tz, label) #get_timezone_name(tz, locale=locale))


[docs]class Babel(BabelBase): """ Allow to load translations from other modules """ _translations_paths = None def __init__(self, *args, **kwargs): BabelBase.__init__(self, *args, **kwargs) def init_app(self, app): super(Babel, self).init_app(app) self._translations_paths = [ (os.path.join(app.root_path, 'translations'), 'messages') ]
[docs] def add_translations(self, module_name, translations_dir='translations', domain='messages'): """ Adds translations from external module. For example:: babel.add_translations('abilian.core') Will add translations files from `abilian.core` module. """ module = importlib.import_module(module_name) for path in (Path(p, translations_dir) for p in module.__path__): if not (path.exists() and path.is_dir()): continue if not os.access(unicode(path), os.R_OK): self.app.logger.warning( "Babel translations: read access not allowed {}, skipping." "".format( repr(unicode((path)).encode('utf-8'))) ) continue self._translations_paths.append((unicode(path), domain))
def _get_translations_multi_paths(): """ Returns the correct gettext translations that should be used for this request. This will never fail and return a dummy translation object if used outside of the request or if a translation cannot be found. """ ctx = _request_ctx_stack.top if ctx is None: return None translations = getattr(ctx, 'babel_translations', None) if translations is None: babel_ext = ctx.app.extensions['babel'] translations = None trs = None # reverse order: thus the application catalog is loaded last, so that # translations from libraries can be overriden for (dirname, domain) in reversed(babel_ext._translations_paths): trs = Translations.load(dirname, locales=[flask_babel.get_locale()], domain=domain) # babel.support.Translations is a subclass of # babel.support.NullTranslations, so we test if object has a 'merge' # method if not trs or not hasattr(trs, 'merge'): # got None or NullTranslations instance continue elif (translations is not None and hasattr(translations, 'merge')): translations.merge(trs) else: translations = trs # ensure translations is at least a NullTranslations object if translations is None: translations = trs ctx.babel_translations = translations return translations # monkey patch flask-babel flask_babel.get_translations = _get_translations_multi_paths #: importable instance of :class:`Babel` babel = Babel()
[docs]def localeselector(): """ Default locale selector used in abilian applications """ # if a user is logged in, use the locale from the user settings user = getattr(g, 'user', None) if user is not None: locale = getattr(user, 'locale', None) if locale: return locale # Otherwise, try to guess the language from the user accept header the browser # transmits. By default we support en/fr. The best match wins. return request.accept_languages.best_match( current_app.config['BABEL_ACCEPT_LANGUAGES'] )
[docs]def timezoneselector(): """ Default timezone selector used in abilian applications """ return LOCALTZ
@contextmanager
[docs]def set_locale(locale): """ Change current locale. Can be used as a context manager to temporary change locale:: with set_locale('fr') as fr_locale: ... :type locale: :class:`babel.core.Locale` or `str` :param locale: locale to use. If it's a string if must be a valid locale specification :rtype: :class:`babel.core.Locale` :return: locale set """ ctx = _request_ctx_stack.top if ctx is None: yield if not isinstance(locale, Locale): locale = Locale.parse(locale) current_locale = getattr(ctx, 'babel_locale', None) ctx.babel_locale = locale yield locale ctx.babel_locale = current_locale
def get_template_i18n(template_name, locale): """ Build template list with preceding locale if found """ if locale is None: return template_name template_list = [] parts = template_name.rsplit('.', 1) root = parts[0] suffix = parts[1] if locale.territory is not None: locale_string = '_'.join([locale.language, locale.territory]) localized_template_path = u'.'.join([root, locale_string, suffix]) template_list.append(localized_template_path) localized_template_path = u'.'.join([root, locale.language, suffix]) template_list.append(localized_template_path) # append the default template_list.append(template_name) return template_list
[docs]def render_template_i18n(template_name_or_list, **context): """ Try to build an ordered list of template to satisfy the current locale """ template_list = [] # Use locale if present in **context if 'locale' in context: locale = Locale.parse(context['locale']) else: # Use get_locale() or default_locale locale = flask_babel.get_locale() if isinstance(template_name_or_list, basestring): template_list = get_template_i18n(template_name_or_list, locale) else: # Search for locale for each member of the list, do not bypass for template in template_name_or_list: template_list.append(get_template_i18n(template, locale)) with set_locale(locale): return render_template(template_list, **context)
_NOT_WORD_RE = re.compile(r'[^\w\s]+', flags=re.UNICODE) def to_lower_ascii(value): value = unicode(value) value = _NOT_WORD_RE.sub(u' ', value) value = unicodedata.normalize('NFKD', value) value = value.encode('ascii', 'ignore') value = value.decode('ascii') value = value.strip().lower() value = re.sub(r'[_\s]+', u' ', value) return value