django1/django/utils/translation.py

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"translation helper functions"
import os, re, sys
import gettext as gettext_module
from cStringIO import StringIO
from django.utils.functional import lazy
try:
import threading
hasThreads = True
except ImportError:
hasThreads = False
if hasThreads:
currentThread = threading.currentThread
else:
def currentThread():
return 'no threading'
# Translations are cached in a dictionary for every language+app tuple.
# The active translations are stored by threadid to make them thread local.
_translations = {}
_active = {}
# The default translation is based on the settings file.
_default = None
# This is a cache for accept-header to translation object mappings to prevent
# the accept parser to run multiple times for one user.
_accepted = {}
def to_locale(language):
"Turns a language name (en-us) into a locale name (en_US)."
p = language.find('-')
if p >= 0:
return language[:p].lower()+'_'+language[p+1:].upper()
else:
return language.lower()
def to_language(locale):
"Turns 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()
class DjangoTranslation(gettext_module.GNUTranslations):
"""
This class sets up the GNUTranslations context with regard to output
charset. Django uses a defined DEFAULT_CHARSET as the output charset on
Python 2.4. With Python 2.3, use DjangoTranslation23.
"""
def __init__(self, *args, **kw):
from django.conf import settings
gettext_module.GNUTranslations.__init__(self, *args, **kw)
# Starting with Python 2.4, there's a function to define
# the output charset. Before 2.4, the output charset is
# identical with the translation file charset.
try:
self.set_output_charset(settings.DEFAULT_CHARSET)
except AttributeError:
pass
self.django_output_charset = settings.DEFAULT_CHARSET
self.__language = '??'
def merge(self, other):
self._catalog.update(other._catalog)
def set_language(self, language):
self.__language = language
def language(self):
return self.__language
def __repr__(self):
return "<DjangoTranslation lang:%s>" % self.__language
class DjangoTranslation23(DjangoTranslation):
"""
Compatibility class that is only used with Python 2.3.
Python 2.3 doesn't support set_output_charset on translation objects and
needs this wrapper class to make sure input charsets from translation files
are correctly translated to output charsets.
With a full switch to Python 2.4, this can be removed from the source.
"""
def gettext(self, msgid):
res = self.ugettext(msgid)
return res.encode(self.django_output_charset)
def ngettext(self, msgid1, msgid2, n):
res = self.ungettext(msgid1, msgid2, n)
return res.encode(self.django_output_charset)
def translation(language):
"""
Returns a translation object.
This translation object will be constructed out of multiple GNUTranslations
objects by merging their catalogs. It will construct a object for the
requested language and add a fallback to the default language, if it's
different from the requested language.
"""
global _translations
t = _translations.get(language, None)
if t is not None:
return t
from django.conf import settings
# set up the right translation class
klass = DjangoTranslation
if sys.version_info < (2, 4):
klass = DjangoTranslation23
globalpath = os.path.join(os.path.dirname(settings.__file__), 'locale')
parts = settings.SETTINGS_MODULE.split('.')
project = __import__(parts[0], {}, {}, [])
projectpath = os.path.join(os.path.dirname(project.__file__), 'locale')
def _fetch(lang, fallback=None):
global _translations
loc = to_locale(lang)
res = _translations.get(lang, None)
if res is not None:
return res
def _translation(path):
try:
t = gettext_module.translation('django', path, [loc], klass)
t.set_language(lang)
return t
except IOError, e:
return None
res = _translation(globalpath)
def _merge(path):
t = _translation(path)
if t is not None:
if res is None:
return t
else:
res.merge(t)
return res
if hasattr(settings, 'LOCALE_PATHS'):
for localepath in settings.LOCALE_PATHS:
if os.path.isdir(localepath):
res = _merge(localepath)
if os.path.isdir(projectpath):
res = _merge(projectpath)
for appname in settings.INSTALLED_APPS:
p = appname.rfind('.')
if p >= 0:
app = getattr(__import__(appname[:p], {}, {}, [appname[p+1:]]), appname[p+1:])
else:
app = __import__(appname, {}, {}, [])
apppath = os.path.join(os.path.dirname(app.__file__), 'locale')
if os.path.isdir(apppath):
res = _merge(apppath)
if res is None:
if fallback is not None:
res = fallback
else:
return gettext_module.NullTranslations()
_translations[lang] = res
return res
default_translation = _fetch(settings.LANGUAGE_CODE)
current_translation = _fetch(language, fallback=default_translation)
return current_translation
def activate(language):
"""
Fetches the translation object for a given tuple of application name and
language and installs it as the current translation object for the current
thread.
"""
_active[currentThread()] = translation(language)
def deactivate():
"""
Deinstalls the currently active translation object so that further _ calls
will resolve against the default translation object, again.
"""
global _active
if _active.has_key(currentThread()):
del _active[currentThread()]
def get_language():
"Returns the currently selected language."
t = _active.get(currentThread(), None)
if t is not None:
try:
return to_language(t.language())
except AttributeError:
pass
# If we don't have a real translation object, assume it's the default language.
from django.conf.settings import LANGUAGE_CODE
return LANGUAGE_CODE
def catalog():
"""
This function returns the current active catalog for further processing.
This can be used if you need to modify the catalog or want to access the
whole message catalog instead of just translating one string.
"""
global _default, _active
t = _active.get(currentThread(), None)
if t is not None:
return t
if _default is None:
from django.conf import settings
_default = translation(settings.LANGUAGE_CODE)
return _default
def gettext(message):
"""
This function will be patched into the builtins module to provide the _
helper function. It will use the current thread as a discriminator to find
the translation object to use. If no current translation is activated, the
message will be run through the default translation object.
"""
global _default, _active
t = _active.get(currentThread(), None)
if t is not None:
return t.gettext(message)
if _default is None:
from django.conf import settings
_default = translation(settings.LANGUAGE_CODE)
return _default.gettext(message)
def gettext_noop(message):
"""
Marks strings for translation but doesn't translate them now. This can be
used to store strings in global variables that should stay in the base
language (because they might be used externally) and will be translated later.
"""
return message
def ngettext(singular, plural, number):
"""
Returns the translation of either the singular or plural, based on the number.
"""
global _default, _active
t = _active.get(currentThread(), None)
if t is not None:
return t.ngettext(singular, plural, number)
if _default is None:
from django.conf import settings
_default = translation(settings.LANGUAGE_CODE)
return _default.ngettext(singular, plural, number)
gettext_lazy = lazy(gettext, str)
ngettext_lazy = lazy(ngettext, str)
def check_for_language(lang_code):
"""
Checks whether there is a global language file for the given language code.
This is used to decide whether a user-provided language is available. This is
only used for language codes from either the cookies or session.
"""
from django.conf import settings
globalpath = os.path.join(os.path.dirname(settings.__file__), 'locale')
if gettext_module.find('django', globalpath, [to_locale(lang_code)]) is not None:
return True
else:
return False
def get_language_from_request(request):
"""
Analyzes the request to find what language the user wants the system to show.
Only languages listed in settings.LANGUAGES are taken into account. If the user
requests a sublanguage where we have a main language, we send out the main language.
"""
global _accepted
from django.conf import settings
globalpath = os.path.join(os.path.dirname(settings.__file__), 'locale')
supported = dict(settings.LANGUAGES)
if hasattr(request, 'session'):
lang_code = request.session.get('django_language', None)
if lang_code in supported and lang_code is not None and check_for_language(lang_code):
return lang_code
lang_code = request.COOKIES.get('django_language', None)
if lang_code in supported and lang_code is not None and check_for_language(lang_code):
return lang_code
accept = request.META.get('HTTP_ACCEPT_LANGUAGE', None)
if accept is not None:
t = _accepted.get(accept, None)
if t is not None:
return t
def _parsed(el):
p = el.find(';q=')
if p >= 0:
lang = el[:p].strip()
order = int(float(el[p+3:].strip())*100)
else:
lang = el
order = 100
p = lang.find('-')
if p >= 0:
mainlang = lang[:p]
else:
mainlang = lang
return (lang, mainlang, order)
langs = [_parsed(el) for el in accept.split(',')]
langs.sort(lambda a,b: -1*cmp(a[2], b[2]))
for lang, mainlang, order in langs:
if lang in supported or mainlang in supported:
langfile = gettext_module.find('django', globalpath, [to_locale(lang)])
if langfile:
# reconstruct the actual language from the language
# filename, because otherwise we might incorrectly
# report de_DE if we only have de available, but
# did find de_DE because of language normalization
lang = langfile[len(globalpath):].split(os.path.sep)[1]
_accepted[accept] = lang
return lang
return settings.LANGUAGE_CODE
def get_date_formats():
"""
This function checks whether translation files provide a translation for some
technical message ID to store date and time formats. If it doesn't contain
one, the formats provided in the settings will be used.
"""
from django.conf.settings import DATE_FORMAT, DATETIME_FORMAT, TIME_FORMAT
date_format = _('DATE_FORMAT')
datetime_format = _('DATETIME_FORMAT')
time_format = _('TIME_FORMAT')
if date_format == 'DATE_FORMAT':
date_format = DATE_FORMAT
if datetime_format == 'DATETIME_FORMAT':
datetime_format = DATETIME_FORMAT
if time_format == 'TIME_FORMAT':
time_format = TIME_FORMAT
return (date_format, datetime_format, time_format)
def install():
"""
Installs the gettext function as the default translation function under
the name _.
"""
__builtins__['_'] = gettext
dot_re = re.compile(r'\S')
def blankout(src, char):
"""
Changes every non-whitespace character to the given char.
Used in the templateize function.
"""
return dot_re.sub(char, src)
inline_re = re.compile(r"""^\s*trans\s+((?:".*?")|(?:'.*?'))\s*""")
block_re = re.compile(r"""^\s*blocktrans(?:\s+|$)""")
endblock_re = re.compile(r"""^\s*endblocktrans$""")
plural_re = re.compile(r"""^\s*plural$""")
constant_re = re.compile(r"""_\(((?:".*?")|(?:'.*?'))\)""")
def templateize(src):
"""
Turns a Django template into something that is understood by xgettext. It
does so by translating the Django translation tags into standard gettext
function invocations.
"""
from django.core.template import Lexer, TOKEN_TEXT, TOKEN_VAR, TOKEN_BLOCK
out = StringIO()
intrans = False
inplural = False
singular = []
plural = []
for t in Lexer(src, None).tokenize():
if intrans:
if t.token_type == TOKEN_BLOCK:
endbmatch = endblock_re.match(t.contents)
pluralmatch = plural_re.match(t.contents)
if endbmatch:
if inplural:
out.write(' ngettext(%r,%r,count) ' % (''.join(singular), ''.join(plural)))
for part in singular:
out.write(blankout(part, 'S'))
for part in plural:
out.write(blankout(part, 'P'))
else:
out.write(' gettext(%r) ' % ''.join(singular))
for part in singular:
out.write(blankout(part, 'S'))
intrans = False
inplural = False
singular = []
plural = []
elif pluralmatch:
inplural = True
else:
raise SyntaxError, "Translation blocks must not include other block tags: %s" % t.contents
elif t.token_type == TOKEN_VAR:
if inplural:
plural.append('%%(%s)s' % t.contents)
else:
singular.append('%%(%s)s' % t.contents)
elif t.token_type == TOKEN_TEXT:
if inplural:
plural.append(t.contents)
else:
singular.append(t.contents)
else:
if t.token_type == TOKEN_BLOCK:
imatch = inline_re.match(t.contents)
bmatch = block_re.match(t.contents)
cmatches = constant_re.findall(t.contents)
if imatch:
g = imatch.group(1)
if g[0] == '"': g = g.strip('"')
elif g[0] == "'": g = g.strip("'")
out.write(' gettext(%r) ' % g)
elif bmatch:
intrans = True
inplural = False
singular = []
plural = []
elif cmatches:
for cmatch in cmatches:
out.write(' _(%s) ' % cmatch)
else:
out.write(blankout(t.contents, 'B'))
elif t.token_type == TOKEN_VAR:
parts = t.contents.split('|')
cmatch = constant_re.match(parts[0])
if cmatch:
out.write(' _(%s) ' % cmatch.group(1))
for p in parts[1:]:
if p.find(':_(') >= 0:
out.write(' %s ' % p.split(':',1)[1])
else:
out.write(blankout(p, 'F'))
else:
out.write(blankout(t.contents, 'X'))
return out.getvalue()