i18n patch - references #65

git-svn-id: http://code.djangoproject.com/svn/django/branches/i18n@726 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 195 insertions, 0 deletions

diff --git a/django/utils/translation.py b/django/utils/translation.py
new file mode 100644
index 0000000000..293c7ed261
--- /dev/null
+++ b/django/utils/translation.py
@@ -0,0 +1,195 @@
+"translation helper functions"
+
+import os
+import gettext as gettext_module
+
+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 = {}
+
+class DjangoTranslation(gettext_module.GNUTranslations):
+    """
+    This class sets up the GNUTranslations context with
+    regard to output charset. Django allways uses utf-8
+    as the output charset.
+    """
+
+    def __init__(self, *args, **kw):
+        gettext_module.GNUTranslations.__init__(self, *args, **kw)
+        self.__charset = self.charset()
+        self.set_output_charset('utf-8')
+        self.__app = '?.?.?'
+        self.__language = '??'
+    
+    def set_app_and_language(self, app, language):
+        self.__app = app
+        self.__language = language
+    
+    def __repr__(self):
+        return "<DjangoTranslation app:%s lang:%s>" % (self.__app, self.__language)
+
+def translation(appname, language):
+    """
+    This function returns a translation object.
+    app must be the fully qualified name of the
+    application.
+
+    This function will first look into the app
+    messages directory for the django message file,
+    then in the project messages directory for the
+    django message file and last in the global
+    messages directory for the django message file.
+    """
+
+    t = _translations.get((appname, language), None)
+    if t is not None:
+        return t
+    
+    from django.conf import settings
+
+    globalpath = os.path.join(os.path.dirname(settings.__file__), 'locale')
+
+    try:
+        t = gettext_module.translation('django', globalpath, [language, settings.LANGUAGE_CODE], DjangoTranslation)
+        t.set_app_and_language(appname, language)
+    except IOError: t = gettext_module.NullTranslations()
+    _translations[(appname, language)] = t
+
+    if appname != '*':
+        parts = appname.split('.')
+        project = __import__(parts[0], {}, {}, [])
+        app = __import__(appname, {}, {}, ['views'])
+
+        apppath = os.path.join(os.path.dirname(app.__file__), 'locale')
+        projectpath = os.path.join(os.path.dirname(project.__file__), 'locale')
+
+        try:
+            t = gettext_module.translation('django', projectpath, [language, settings.LANGUAGE_CODE], DjangoTranslation)
+            t.set_app_and_language(appname, language)
+        except IOError: t = None
+        if t is not None:
+            t.add_fallback(_translations[(appname, language)])
+            _translations[(appname, language)] = t
+
+        try:
+            t = gettext_module.translation('django', apppath, [language, settings.LANGUAGE_CODE], DjangoTranslation)
+            t.set_app_and_language(appname, language)
+        except IOError: t = None
+        if t is not None:
+            t.add_fallback(_translations[(appname, language)])
+            _translations[(appname, language)] = t
+
+    return _translations[(appname, language)]
+
+def activate(appname, language):
+    """
+    This function 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.
+    """
+    t = translation(appname, language)
+    _active[currentThread()] = t
+
+def deactivate():
+    """
+    This function deinstalls the currently active translation
+    object so that further _ calls will resolve against the
+    default translation object, again.
+    """
+    del _active[currentThread()]
+
+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 get_language_from_request(request):
+    """
+    analyze the request to find what language the user
+    wants the system to show.
+    """
+    global _accepted
+
+    if hasattr(request, 'session'):
+        lang = getattr(request.session, 'django_language', None)
+        if lang is not None:
+            return lang
+    
+    lang = request.COOKIES.get('django_language', None)
+    if lang is not None:
+        return lang
+    
+    from django.conf import settings
+
+    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
+            return (lang, order)
+
+        langs = [_parsed(el) for el in accept.split(',')]
+        langs.sort(lambda a,b: cmp(a[1], b[1]))
+
+        globalpath = os.path.join(os.path.dirname(settings.__file__), 'locale')
+
+        for lang, order in langs:
+            if os.path.isfile(os.path.join(globalpath, lang, 'LC_MESSAGES', 'django.mo')):
+                _accepted[accept] = lang
+                return lang
+    
+    return settings.LANGUAGE_CODE
+
+def install():
+    """
+    This installs the gettext function as the default
+    translation function under the name _.
+    """
+    __builtins__['_'] = gettext
+