django1/django/utils/translation/__init__.py

148 lines
4.5 KiB
Python

"""
Internationalization support.
"""
from django.utils.encoding import force_unicode
from django.utils.functional import lazy
__all__ = [
'activate', 'deactivate', 'override', 'deactivate_all',
'get_language', 'get_language_from_request',
'get_language_info', 'get_language_bidi',
'check_for_language', 'to_locale', 'templatize', 'string_concat',
'gettext', 'gettext_lazy', 'gettext_noop',
'ugettext', 'ugettext_lazy', 'ugettext_noop',
'ngettext', 'ngettext_lazy',
'ungettext', 'ungettext_lazy',
'pgettext', 'pgettext_lazy',
'npgettext', 'npgettext_lazy',
]
# Here be dragons, so a short explanation of the logic won't hurt:
# We are trying to solve two problems: (1) access settings, in particular
# settings.USE_I18N, as late as possible, so that modules can be imported
# without having to first configure Django, and (2) if some other code creates
# a reference to one of these functions, don't break that reference when we
# replace the functions with their real counterparts (once we do access the
# settings).
class Trans(object):
"""
The purpose of this class is to store the actual translation function upon
receiving the first call to that function. After this is done, changes to
USE_I18N will have no effect to which function is served upon request. If
your tests rely on changing USE_I18N, you can delete all the functions
from _trans.__dict__.
Note that storing the function with setattr will have a noticeable
performance effect, as access to the function goes the normal path,
instead of using __getattr__.
"""
def __getattr__(self, real_name):
from django.conf import settings
if settings.USE_I18N:
from django.utils.translation import trans_real as trans
else:
from django.utils.translation import trans_null as trans
setattr(self, real_name, getattr(trans, real_name))
return getattr(trans, real_name)
_trans = Trans()
# The Trans class is no more needed, so remove it from the namespace.
del Trans
def gettext_noop(message):
return _trans.gettext_noop(message)
ugettext_noop = gettext_noop
def gettext(message):
return _trans.gettext(message)
def ngettext(singular, plural, number):
return _trans.ngettext(singular, plural, number)
def ugettext(message):
return _trans.ugettext(message)
def ungettext(singular, plural, number):
return _trans.ungettext(singular, plural, number)
def pgettext(context, message):
return _trans.pgettext(context, message)
def npgettext(context, singular, plural, number):
return _trans.npgettext(context, singular, plural, number)
ngettext_lazy = lazy(ngettext, str)
gettext_lazy = lazy(gettext, str)
ungettext_lazy = lazy(ungettext, unicode)
ugettext_lazy = lazy(ugettext, unicode)
pgettext_lazy = lazy(pgettext, unicode)
npgettext_lazy = lazy(npgettext, unicode)
def activate(language):
return _trans.activate(language)
def deactivate():
return _trans.deactivate()
class override(object):
def __init__(self, language, deactivate=False):
self.language = language
self.deactivate = deactivate
self.old_language = get_language()
def __enter__(self):
if self.language is not None:
activate(self.language)
else:
deactivate_all()
def __exit__(self, exc_type, exc_value, traceback):
if self.deactivate:
deactivate()
else:
activate(self.old_language)
def get_language():
return _trans.get_language()
def get_language_bidi():
return _trans.get_language_bidi()
def check_for_language(lang_code):
return _trans.check_for_language(lang_code)
def to_locale(language):
return _trans.to_locale(language)
def get_language_from_request(request, check_path=False):
return _trans.get_language_from_request(request, check_path)
def get_language_from_path(path):
return _trans.get_language_from_path(path)
def templatize(src, origin=None):
return _trans.templatize(src, origin)
def deactivate_all():
return _trans.deactivate_all()
def _string_concat(*strings):
"""
Lazy variant of string concatenation, needed for translations that are
constructed from multiple parts.
"""
return u''.join([force_unicode(s) for s in strings])
string_concat = lazy(_string_concat, unicode)
def get_language_info(lang_code):
from django.conf.locale import LANG_INFO
try:
return LANG_INFO[lang_code]
except KeyError:
raise KeyError("Unknown language code %r." % lang_code)