# -*- coding: utf-8 -*-
# SPDX-License-Identifier: AGPL-3.0-or-later
# lint: pylint
"""Initialize :py:obj:`LOCALE_NAMES`, :py:obj:`RTL_LOCALES`.
"""
from typing import Set, Optional, List
import os
import pathlib
import babel
from babel.support import Translations
import babel.languages
import babel.core
import flask_babel
import flask
from flask.ctx import has_request_context
from searx import logger
logger = logger.getChild('locales')
# safe before monkey patching flask_babel.get_translations
_flask_babel_get_translations = flask_babel.get_translations
LOCALE_NAMES = {}
"""Mapping of locales and their description. Locales e.g. 'fr' or 'pt-BR' (see
:py:obj:`locales_initialize`).
:meta hide-value:
"""
RTL_LOCALES: Set[str] = set()
"""List of *Right-To-Left* locales e.g. 'he' or 'fa-IR' (see
:py:obj:`locales_initialize`)."""
ADDITIONAL_TRANSLATIONS = {
"dv": "ދިވެހި (Dhivehi)",
"oc": "Occitan",
"szl": "Ślōnski (Silesian)",
"pap": "Papiamento",
}
"""Additional languages SearXNG has translations for but not supported by
python-babel (see :py:obj:`locales_initialize`)."""
LOCALE_BEST_MATCH = {
"dv": "si",
"oc": 'fr-FR',
"szl": "pl",
"nl-BE": "nl",
"zh-HK": "zh-Hant-TW",
"pap": "pt-BR",
}
"""Map a locale we do not have a translations for to a locale we have a
translation for. By example: use Taiwan version of the translation for Hong
Kong."""
def localeselector():
locale = 'en'
if has_request_context():
value = flask.request.preferences.get_value('locale')
if value:
locale = value
# first, set the language that is not supported by babel
if locale in ADDITIONAL_TRANSLATIONS:
flask.request.form['use-translation'] = locale
# second, map locale to a value python-babel supports
locale = LOCALE_BEST_MATCH.get(locale, locale)
if locale == '':
# if there is an error loading the preferences
# the locale is going to be ''
locale = 'en'
# babel uses underscore instead of hyphen.
locale = locale.replace('-', '_')
return locale
[docs]
def get_translations():
"""Monkey patch of :py:obj:`flask_babel.get_translations`"""
if has_request_context():
use_translation = flask.request.form.get('use-translation')
if use_translation in ADDITIONAL_TRANSLATIONS:
babel_ext = flask_babel.current_app.extensions['babel']
return Translations.load(babel_ext.translation_directories[0], use_translation)
return _flask_babel_get_translations()
[docs]
def get_locale_descr(locale, locale_name):
"""Get locale name e.g. 'Français - fr' or 'Português (Brasil) - pt-BR'
:param locale: instance of :py:class:`Locale`
:param locale_name: name e.g. 'fr' or 'pt_BR' (delimiter is *underscore*)
"""
native_language, native_territory = _get_locale_descr(locale, locale_name)
english_language, english_territory = _get_locale_descr(locale, 'en')
if native_territory == english_territory:
english_territory = None
if not native_territory and not english_territory:
if native_language == english_language:
return native_language
return native_language + ' (' + english_language + ')'
result = native_language + ', ' + native_territory + ' (' + english_language
if english_territory:
return result + ', ' + english_territory + ')'
return result + ')'
def _get_locale_descr(locale, language_code):
language_name = locale.get_language_name(language_code).capitalize()
if language_name and ('a' <= language_name[0] <= 'z'):
language_name = language_name.capitalize()
territory_name = locale.get_territory_name(language_code)
return language_name, territory_name
[docs]
def locales_initialize(directory=None):
"""Initialize locales environment of the SearXNG session.
- monkey patch :py:obj:`flask_babel.get_translations` by :py:obj:`get_translations`
- init global names :py:obj:`LOCALE_NAMES`, :py:obj:`RTL_LOCALES`
"""
directory = directory or pathlib.Path(__file__).parent / 'translations'
logger.debug("locales_initialize: %s", directory)
flask_babel.get_translations = get_translations
for tag, descr in ADDITIONAL_TRANSLATIONS.items():
locale = babel.Locale.parse(LOCALE_BEST_MATCH[tag], sep='-')
LOCALE_NAMES[tag] = descr
if locale.text_direction == 'rtl':
RTL_LOCALES.add(tag)
for tag in LOCALE_BEST_MATCH:
descr = LOCALE_NAMES.get(tag)
if not descr:
locale = babel.Locale.parse(tag, sep='-')
LOCALE_NAMES[tag] = get_locale_descr(locale, tag.replace('-', '_'))
if locale.text_direction == 'rtl':
RTL_LOCALES.add(tag)
for dirname in sorted(os.listdir(directory)):
# Based on https://flask-babel.tkte.ch/_modules/flask_babel.html#Babel.list_translations
if not os.path.isdir(os.path.join(directory, dirname, 'LC_MESSAGES')):
continue
tag = dirname.replace('_', '-')
descr = LOCALE_NAMES.get(tag)
if not descr:
locale = babel.Locale.parse(dirname)
LOCALE_NAMES[tag] = get_locale_descr(locale, dirname)
if locale.text_direction == 'rtl':
RTL_LOCALES.add(tag)
[docs]
def region_tag(locale: babel.Locale) -> str:
"""Returns SearXNG's region tag from the locale (e.g. zh-TW , en-US)."""
if not locale.territory:
raise ValueError('%s missed a territory')
return locale.language + '-' + locale.territory
[docs]
def language_tag(locale: babel.Locale) -> str:
"""Returns SearXNG's language tag from the locale and if exits, the tag
includes the script name (e.g. en, zh_Hant).
"""
sxng_lang = locale.language
if locale.script:
sxng_lang += '_' + locale.script
return sxng_lang
[docs]
def get_locale(locale_tag: str) -> Optional[babel.Locale]:
"""Returns a :py:obj:`babel.Locale` object parsed from argument
``locale_tag``"""
try:
locale = babel.Locale.parse(locale_tag, sep='-')
return locale
except babel.core.UnknownLocaleError:
return None
[docs]
def get_official_locales(
territory: str, languages=None, regional: bool = False, de_facto: bool = True
) -> Set[babel.Locale]:
"""Returns a list of :py:obj:`babel.Locale` with languages from
:py:obj:`babel.languages.get_official_languages`.
:param territory: The territory (country or region) code.
:param languages: A list of language codes the languages from
:py:obj:`babel.languages.get_official_languages` should be in
(intersection). If this argument is ``None``, all official languages in
this territory are used.
:param regional: If the regional flag is set, then languages which are
regionally official are also returned.
:param de_facto: If the de_facto flag is set to `False`, then languages
which are “de facto” official are not returned.
"""
ret_val = set()
o_languages = babel.languages.get_official_languages(territory, regional=regional, de_facto=de_facto)
if languages:
languages = [l.lower() for l in languages]
o_languages = set(l for l in o_languages if l.lower() in languages)
for lang in o_languages:
try:
locale = babel.Locale.parse(lang + '_' + territory)
ret_val.add(locale)
except babel.UnknownLocaleError:
continue
return ret_val
[docs]
def get_engine_locale(searxng_locale, engine_locales, default=None):
"""Return engine's language (aka locale) string that best fits to argument
``searxng_locale``.
Argument ``engine_locales`` is a python dict that maps *SearXNG locales* to
corresponding *engine locales*::
<engine>: {
# SearXNG string : engine-string
'ca-ES' : 'ca_ES',
'fr-BE' : 'fr_BE',
'fr-CA' : 'fr_CA',
'fr-CH' : 'fr_CH',
'fr' : 'fr_FR',
...
'pl-PL' : 'pl_PL',
'pt-PT' : 'pt_PT'
..
'zh' : 'zh'
'zh_Hans' : 'zh'
'zh_Hant' : 'zh_TW'
}
.. hint::
The *SearXNG locale* string has to be known by babel!
If there is no direct 1:1 mapping, this functions tries to narrow down
engine's language (locale). If no value can be determined by these
approximation attempts the ``default`` value is returned.
Assumptions:
A. When user select a language the results should be optimized according to
the selected language.
B. When user select a language and a territory the results should be
optimized with first priority on territory and second on language.
First approximation rule (*by territory*):
When the user selects a locale with territory (and a language), the
territory has priority over the language. If any of the official languages
in the territory is supported by the engine (``engine_locales``) it will
be used.
Second approximation rule (*by language*):
If "First approximation rule" brings no result or the user selects only a
language without a territory. Check in which territories the language
has an official status and if one of these territories is supported by the
engine.
"""
# pylint: disable=too-many-branches, too-many-return-statements
engine_locale = engine_locales.get(searxng_locale)
if engine_locale is not None:
# There was a 1:1 mapping (e.g. a region "fr-BE --> fr_BE" or a language
# "zh --> zh"), no need to narrow language-script nor territory.
return engine_locale
try:
locale = babel.Locale.parse(searxng_locale, sep='-')
except babel.core.UnknownLocaleError:
try:
locale = babel.Locale.parse(searxng_locale.split('-')[0])
except babel.core.UnknownLocaleError:
return default
searxng_lang = language_tag(locale)
engine_locale = engine_locales.get(searxng_lang)
if engine_locale is not None:
# There was a 1:1 mapping (e.g. "zh-HK --> zh_Hant" or "zh-CN --> zh_Hans")
return engine_locale
# SearXNG's selected locale is not supported by the engine ..
if locale.territory:
# Try to narrow by *official* languages in the territory (??-XX).
for official_language in babel.languages.get_official_languages(locale.territory, de_facto=True):
searxng_locale = official_language + '-' + locale.territory
engine_locale = engine_locales.get(searxng_locale)
if engine_locale is not None:
return engine_locale
# Engine does not support one of the official languages in the territory or
# there is only a language selected without a territory.
# Now lets have a look if the searxng_lang (the language selected by the
# user) is a official language in other territories. If so, check if
# engine does support the searxng_lang in this other territory.
if locale.language:
terr_lang_dict = {}
for territory, langs in babel.core.get_global("territory_languages").items():
if not langs.get(searxng_lang, {}).get('official_status'):
continue
terr_lang_dict[territory] = langs.get(searxng_lang)
# first: check fr-FR, de-DE .. is supported by the engine
# exception: 'en' --> 'en-US'
territory = locale.language.upper()
if territory == 'EN':
territory = 'US'
if terr_lang_dict.get(territory):
searxng_locale = locale.language + '-' + territory
engine_locale = engine_locales.get(searxng_locale)
if engine_locale is not None:
return engine_locale
# second: sort by population_percent and take first match
# drawback of "population percent": if there is a territory with a
# small number of people (e.g 100) but the majority speaks the
# language, then the percentage might be 100% (--> 100 people) but in
# a different territory with more people (e.g. 10.000) where only 10%
# speak the language the total amount of speaker is higher (--> 200
# people).
#
# By example: The population of Saint-Martin is 33.000, of which 100%
# speak French, but this is less than the 30% of the approximately 2.5
# million Belgian citizens
#
# - 'fr-MF', 'population_percent': 100.0, 'official_status': 'official'
# - 'fr-BE', 'population_percent': 38.0, 'official_status': 'official'
terr_lang_list = []
for k, v in terr_lang_dict.items():
terr_lang_list.append((k, v))
for territory, _lang in sorted(terr_lang_list, key=lambda item: item[1]['population_percent'], reverse=True):
searxng_locale = locale.language + '-' + territory
engine_locale = engine_locales.get(searxng_locale)
if engine_locale is not None:
return engine_locale
# No luck: narrow by "language from territory" and "territory from language"
# does not fit to a locale supported by the engine.
if engine_locale is None:
engine_locale = default
return default
[docs]
def match_locale(searxng_locale: str, locale_tag_list: List[str], fallback: Optional[str] = None) -> Optional[str]:
"""Return tag from ``locale_tag_list`` that best fits to ``searxng_locale``.
:param str searxng_locale: SearXNG's internal representation of locale (de,
de-DE, fr-BE, zh, zh-CN, zh-TW ..).
:param list locale_tag_list: The list of locale tags to select from
:param str fallback: fallback locale tag (if unset --> ``None``)
The rules to find a match are implemented in :py:obj:`get_engine_locale`,
the ``engine_locales`` is build up by :py:obj:`build_engine_locales`.
.. hint::
The *SearXNG locale* string and the members of ``locale_tag_list`` has to
be known by babel! The :py:obj:`ADDITIONAL_TRANSLATIONS` are used in the
UI and are not known by babel --> will be ignored.
"""
# searxng_locale = 'es'
# locale_tag_list = ['es-AR', 'es-ES', 'es-MX']
if not searxng_locale:
return fallback
locale = get_locale(searxng_locale)
if locale is None:
return fallback
# normalize to a SearXNG locale that can be passed to get_engine_locale
searxng_locale = language_tag(locale)
if locale.territory:
searxng_locale = region_tag(locale)
# clean up locale_tag_list
tag_list = []
for tag in locale_tag_list:
if tag in ('all', 'auto') or tag in ADDITIONAL_TRANSLATIONS:
continue
tag_list.append(tag)
# emulate fetch_traits
engine_locales = build_engine_locales(tag_list)
return get_engine_locale(searxng_locale, engine_locales, default=fallback)
[docs]
def build_engine_locales(tag_list: List[str]):
"""From a list of locale tags a dictionary is build that can be passed by
argument ``engine_locales`` to :py:obj:`get_engine_locale`. This function
is mainly used by :py:obj:`match_locale` and is similar to what the
``fetch_traits(..)`` function of engines do.
If there are territory codes in the ``tag_list`` that have a *script code*
additional keys are added to the returned dictionary.
.. code:: python
>>> import locales
>>> engine_locales = locales.build_engine_locales(['en', 'en-US', 'zh', 'zh-CN', 'zh-TW'])
>>> engine_locales
{
'en': 'en', 'en-US': 'en-US',
'zh': 'zh', 'zh-CN': 'zh-CN', 'zh_Hans': 'zh-CN',
'zh-TW': 'zh-TW', 'zh_Hant': 'zh-TW'
}
>>> get_engine_locale('zh-Hans', engine_locales)
'zh-CN'
This function is a good example to understand the language/region model
of SearXNG:
SearXNG only distinguishes between **search languages** and **search
regions**, by adding the *script-tags*, languages with *script-tags* can
be assigned to the **regions** that SearXNG supports.
"""
engine_locales = {}
for tag in tag_list:
locale = get_locale(tag)
if locale is None:
logger.warning("build_engine_locales: skip locale tag %s / unknown by babel", tag)
continue
if locale.territory:
engine_locales[region_tag(locale)] = tag
if locale.script:
engine_locales[language_tag(locale)] = tag
else:
engine_locales[language_tag(locale)] = tag
return engine_locales
