diff options
Diffstat (limited to 'keystone/openstack/common/gettextutils.py')
| -rw-r--r-- | keystone/openstack/common/gettextutils.py | 263 |
1 files changed, 259 insertions, 4 deletions
diff --git a/keystone/openstack/common/gettextutils.py b/keystone/openstack/common/gettextutils.py index 55ba3387..ed085370 100644 --- a/keystone/openstack/common/gettextutils.py +++ b/keystone/openstack/common/gettextutils.py @@ -1,6 +1,7 @@ # vim: tabstop=4 shiftwidth=4 softtabstop=4 # Copyright 2012 Red Hat, Inc. +# Copyright 2013 IBM Corp. # All Rights Reserved. # # Licensed under the Apache License, Version 2.0 (the "License"); you may @@ -23,18 +24,27 @@ Usual usage in an openstack.common module: from keystone.openstack.common.gettextutils import _ """ +import copy import gettext +import logging.handlers import os +import re +import UserString + +from babel import localedata +import six _localedir = os.environ.get('keystone'.upper() + '_LOCALEDIR') _t = gettext.translation('keystone', localedir=_localedir, fallback=True) +_AVAILABLE_LANGUAGES = [] + def _(msg): return _t.ugettext(msg) -def install(domain): +def install(domain, lazy=False): """Install a _() function using the given translation domain. Given a translation domain, install a _() function using gettext's @@ -44,7 +54,252 @@ def install(domain): overriding the default localedir (e.g. /usr/share/locale) using a translation-domain-specific environment variable (e.g. NOVA_LOCALEDIR). + + :param domain: the translation domain + :param lazy: indicates whether or not to install the lazy _() function. + The lazy _() introduces a way to do deferred translation + of messages by installing a _ that builds Message objects, + instead of strings, which can then be lazily translated into + any available locale. + """ + if lazy: + # NOTE(mrodden): Lazy gettext functionality. + # + # The following introduces a deferred way to do translations on + # messages in OpenStack. We override the standard _() function + # and % (format string) operation to build Message objects that can + # later be translated when we have more information. + # + # Also included below is an example LocaleHandler that translates + # Messages to an associated locale, effectively allowing many logs, + # each with their own locale. + + def _lazy_gettext(msg): + """Create and return a Message object. + + Lazy gettext function for a given domain, it is a factory method + for a project/module to get a lazy gettext function for its own + translation domain (i.e. nova, glance, cinder, etc.) + + Message encapsulates a string so that we can translate + it later when needed. + """ + return Message(msg, domain) + + import __builtin__ + __builtin__.__dict__['_'] = _lazy_gettext + else: + localedir = '%s_LOCALEDIR' % domain.upper() + gettext.install(domain, + localedir=os.environ.get(localedir), + unicode=True) + + +class Message(UserString.UserString, object): + """Class used to encapsulate translatable messages.""" + def __init__(self, msg, domain): + # _msg is the gettext msgid and should never change + self._msg = msg + self._left_extra_msg = '' + self._right_extra_msg = '' + self.params = None + self.locale = None + self.domain = domain + + @property + def data(self): + # NOTE(mrodden): this should always resolve to a unicode string + # that best represents the state of the message currently + + localedir = os.environ.get(self.domain.upper() + '_LOCALEDIR') + if self.locale: + lang = gettext.translation(self.domain, + localedir=localedir, + languages=[self.locale], + fallback=True) + else: + # use system locale for translations + lang = gettext.translation(self.domain, + localedir=localedir, + fallback=True) + + full_msg = (self._left_extra_msg + + lang.ugettext(self._msg) + + self._right_extra_msg) + + if self.params is not None: + full_msg = full_msg % self.params + + return six.text_type(full_msg) + + def _save_dictionary_parameter(self, dict_param): + full_msg = self.data + # look for %(blah) fields in string; + # ignore %% and deal with the + # case where % is first character on the line + keys = re.findall('(?:[^%]|^)%\((\w*)\)[a-z]', full_msg) + + # if we don't find any %(blah) blocks but have a %s + if not keys and re.findall('(?:[^%]|^)%[a-z]', full_msg): + # apparently the full dictionary is the parameter + params = copy.deepcopy(dict_param) + else: + params = {} + for key in keys: + try: + params[key] = copy.deepcopy(dict_param[key]) + except TypeError: + # cast uncopyable thing to unicode string + params[key] = unicode(dict_param[key]) + + return params + + def _save_parameters(self, other): + # we check for None later to see if + # we actually have parameters to inject, + # so encapsulate if our parameter is actually None + if other is None: + self.params = (other, ) + elif isinstance(other, dict): + self.params = self._save_dictionary_parameter(other) + else: + # fallback to casting to unicode, + # this will handle the problematic python code-like + # objects that cannot be deep-copied + try: + self.params = copy.deepcopy(other) + except TypeError: + self.params = unicode(other) + + return self + + # overrides to be more string-like + def __unicode__(self): + return self.data + + def __str__(self): + return self.data.encode('utf-8') + + def __getstate__(self): + to_copy = ['_msg', '_right_extra_msg', '_left_extra_msg', + 'domain', 'params', 'locale'] + new_dict = self.__dict__.fromkeys(to_copy) + for attr in to_copy: + new_dict[attr] = copy.deepcopy(self.__dict__[attr]) + + return new_dict + + def __setstate__(self, state): + for (k, v) in state.items(): + setattr(self, k, v) + + # operator overloads + def __add__(self, other): + copied = copy.deepcopy(self) + copied._right_extra_msg += other.__str__() + return copied + + def __radd__(self, other): + copied = copy.deepcopy(self) + copied._left_extra_msg += other.__str__() + return copied + + def __mod__(self, other): + # do a format string to catch and raise + # any possible KeyErrors from missing parameters + self.data % other + copied = copy.deepcopy(self) + return copied._save_parameters(other) + + def __mul__(self, other): + return self.data * other + + def __rmul__(self, other): + return other * self.data + + def __getitem__(self, key): + return self.data[key] + + def __getslice__(self, start, end): + return self.data.__getslice__(start, end) + + def __getattribute__(self, name): + # NOTE(mrodden): handle lossy operations that we can't deal with yet + # These override the UserString implementation, since UserString + # uses our __class__ attribute to try and build a new message + # after running the inner data string through the operation. + # At that point, we have lost the gettext message id and can just + # safely resolve to a string instead. + ops = ['capitalize', 'center', 'decode', 'encode', + 'expandtabs', 'ljust', 'lstrip', 'replace', 'rjust', 'rstrip', + 'strip', 'swapcase', 'title', 'translate', 'upper', 'zfill'] + if name in ops: + return getattr(self.data, name) + else: + return UserString.UserString.__getattribute__(self, name) + + +def get_available_languages(domain): + """Lists the available languages for the given translation domain. + + :param domain: the domain to get languages for """ - gettext.install(domain, - localedir=os.environ.get(domain.upper() + '_LOCALEDIR'), - unicode=True) + if _AVAILABLE_LANGUAGES: + return _AVAILABLE_LANGUAGES + + localedir = '%s_LOCALEDIR' % domain.upper() + find = lambda x: gettext.find(domain, + localedir=os.environ.get(localedir), + languages=[x]) + + # NOTE(mrodden): en_US should always be available (and first in case + # order matters) since our in-line message strings are en_US + _AVAILABLE_LANGUAGES.append('en_US') + # NOTE(luisg): Babel <1.0 used a function called list(), which was + # renamed to locale_identifiers() in >=1.0, the requirements master list + # requires >=0.9.6, uncapped, so defensively work with both. We can remove + # this check when the master list updates to >=1.0, and all projects udpate + list_identifiers = (getattr(localedata, 'list', None) or + getattr(localedata, 'locale_identifiers')) + locale_identifiers = list_identifiers() + for i in locale_identifiers: + if find(i) is not None: + _AVAILABLE_LANGUAGES.append(i) + return _AVAILABLE_LANGUAGES + + +def get_localized_message(message, user_locale): + """Gets a localized version of the given message in the given locale.""" + if (isinstance(message, Message)): + if user_locale: + message.locale = user_locale + return unicode(message) + else: + return message + + +class LocaleHandler(logging.Handler): + """Handler that can have a locale associated to translate Messages. + + A quick example of how to utilize the Message class above. + LocaleHandler takes a locale and a target logging.Handler object + to forward LogRecord objects to after translating the internal Message. + """ + + def __init__(self, locale, target): + """Initialize a LocaleHandler + + :param locale: locale to use for translating messages + :param target: logging.Handler object to forward + LogRecord objects to after translation + """ + logging.Handler.__init__(self) + self.locale = locale + self.target = target + + def emit(self, record): + if isinstance(record.msg, Message): + # set the locale and resolve to a string + record.msg.locale = self.locale + + self.target.emit(record) |