Source code for django.utils.translation

"""
Internationalization support.
"""
import re
from contextlib import ContextDecorator

from django.utils.autoreload import autoreload_started, file_changed
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_language', 'to_locale', 'templatize',
    'gettext', 'gettext_lazy', 'gettext_noop',
    'ugettext', 'ugettext_lazy', 'ugettext_noop',
    'ngettext', 'ngettext_lazy',
    'ungettext', 'ungettext_lazy',
    'pgettext', 'pgettext_lazy',
    'npgettext', 'npgettext_lazy',
    'LANGUAGE_SESSION_KEY',
]

LANGUAGE_SESSION_KEY = '_language'


class TranslatorCommentWarning(SyntaxWarning):
    pass


# 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:
    """
    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
            from django.utils.translation.reloader import watch_for_translation_changes, translation_file_changed
            autoreload_started.connect(watch_for_translation_changes, dispatch_uid='translation_file_changed')
            file_changed.connect(translation_file_changed, dispatch_uid='translation_file_changed')
        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


[docs]def gettext_noop(message): return _trans.gettext_noop(message)
ugettext_noop = gettext_noop
[docs]def gettext(message): return _trans.gettext(message)
# An alias since Django 2.0 ugettext = gettext
[docs]def ngettext(singular, plural, number): return _trans.ngettext(singular, plural, number)
# An alias since Django 2.0 ungettext = ngettext
[docs]def pgettext(context, message): return _trans.pgettext(context, message)
[docs]def npgettext(context, singular, plural, number): return _trans.npgettext(context, singular, plural, number)
gettext_lazy = ugettext_lazy = lazy(gettext, str) pgettext_lazy = lazy(pgettext, str) def lazy_number(func, resultclass, number=None, **kwargs): if isinstance(number, int): kwargs['number'] = number proxy = lazy(func, resultclass)(**kwargs) else: original_kwargs = kwargs.copy() class NumberAwareString(resultclass): def __bool__(self): return bool(kwargs['singular']) def _get_number_value(self, values): try: return values[number] except KeyError: raise KeyError( "Your dictionary lacks key '%s\'. Please provide " "it, because it is required to determine whether " "string is singular or plural." % number ) def _translate(self, number_value): kwargs['number'] = number_value return func(**kwargs) def format(self, *args, **kwargs): number_value = self._get_number_value(kwargs) if kwargs and number else args[0] return self._translate(number_value).format(*args, **kwargs) def __mod__(self, rhs): if isinstance(rhs, dict) and number: number_value = self._get_number_value(rhs) else: number_value = rhs translated = self._translate(number_value) try: translated = translated % rhs except TypeError: # String doesn't contain a placeholder for the number. pass return translated proxy = lazy(lambda **kwargs: NumberAwareString(), NumberAwareString)(**kwargs) proxy.__reduce__ = lambda: (_lazy_number_unpickle, (func, resultclass, number, original_kwargs)) return proxy def _lazy_number_unpickle(func, resultclass, number, kwargs): return lazy_number(func, resultclass, number=number, **kwargs)
[docs]def ngettext_lazy(singular, plural, number=None): return lazy_number(ngettext, str, singular=singular, plural=plural, number=number)
# An alias since Django 2.0 ungettext_lazy = ngettext_lazy
[docs]def npgettext_lazy(context, singular, plural, number=None): return lazy_number(npgettext, str, context=context, singular=singular, plural=plural, number=number)
[docs]def activate(language): return _trans.activate(language)
[docs]def deactivate(): return _trans.deactivate()
[docs]class override(ContextDecorator): def __init__(self, language, deactivate=False): self.language = language self.deactivate = deactivate def __enter__(self): self.old_language = get_language() if self.language is not None: activate(self.language) else: deactivate_all() def __exit__(self, exc_type, exc_value, traceback): if self.old_language is None: deactivate_all() elif self.deactivate: deactivate() else: activate(self.old_language)
[docs]def get_language(): return _trans.get_language()
[docs]def get_language_bidi(): return _trans.get_language_bidi()
[docs]def check_for_language(lang_code): return _trans.check_for_language(lang_code)
def to_language(locale): """Turn a locale name (en_US) into a language name (en-us).""" p = locale.find('_') if p >= 0: return locale[:p].lower() + '-' + locale[p + 1:].lower() else: return locale.lower()
[docs]def to_locale(language): """Turn a language name (en-us) into a locale name (en_US).""" language, _, country = language.lower().partition('-') if not country: return language # A language with > 2 characters after the dash only has its first # character after the dash capitalized; e.g. sr-latn becomes sr_Latn. # A language with 2 characters after the dash has both characters # capitalized; e.g. en-us becomes en_US. country, _, tail = country.partition('-') country = country.title() if len(country) > 2 else country.upper() if tail: country += '-' + tail return language + '_' + country
[docs]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)
[docs]def get_supported_language_variant(lang_code, *, strict=False): return _trans.get_supported_language_variant(lang_code, strict)
[docs]def templatize(src, **kwargs): from .template import templatize return templatize(src, **kwargs)
[docs]def deactivate_all(): return _trans.deactivate_all()
[docs]def get_language_info(lang_code): from django.conf.locale import LANG_INFO try: lang_info = LANG_INFO[lang_code] if 'fallback' in lang_info and 'name' not in lang_info: info = get_language_info(lang_info['fallback'][0]) else: info = lang_info except KeyError: if '-' not in lang_code: raise KeyError("Unknown language code %s." % lang_code) generic_lang_code = lang_code.split('-')[0] try: info = LANG_INFO[generic_lang_code] except KeyError: raise KeyError("Unknown language code %s and %s." % (lang_code, generic_lang_code)) if info: info['name_translated'] = gettext_lazy(info['name']) return info
trim_whitespace_re = re.compile(r'\s*\n\s*') def trim_whitespace(s): return trim_whitespace_re.sub(' ', s.strip())