Support for different text domains

Both gettext and Babel make heavy use of what is called the text domain
or message domain [1]. This essentially is a unique name that identifies
the application, and it's also used to name the `pot`, `po` and `mo`
files. The code and the documentation currently assume that the domain
is always ``messages``, which is fine for a standalone application. But
when integrating with other applications or migrating old code bases you
might need to use a different domain.

This patch adds a new optional configuration option to define the
domain.

It also adds documentation for the BABEL_TRANSLATION_DIRECTORIES option
added on 11c7b29.

[1]
https://www.gnu.org/software/gawk/manual/html_node/Explaining-gettext.html

Author: amercader

docs/index.rst

@@ -38,17 +38,23 @@ object after configuring the application::
     babel = Babel(app)
 
 The babel object itself can be used to configure the babel support
-further.  Babel has two configuration values that can be used to change
-some internal defaults:
-
-=========================== =============================================
-`BABEL_DEFAULT_LOCALE`      The default locale to use if no locale
-                            selector is registered.  This defaults
-                            to ``'en'``.
-`BABEL_DEFAULT_TIMEZONE`    The timezone to use for user facing dates.
-                            This defaults to ``'UTC'`` which also is the
-                            timezone your application must use internally.
-=========================== =============================================
+further.  Babel has the following configuration values that can be used to
+change some internal defaults:
+
+=============================== =============================================
+`BABEL_DEFAULT_LOCALE`          The default locale to use if no locale
+                                selector is registered.  This defaults
+                                to ``'en'``.
+`BABEL_DEFAULT_TIMEZONE`        The timezone to use for user facing dates.
+                                This defaults to ``'UTC'`` which also is the
+                                timezone your application must use internally.
+`BABEL_TRANSLATION_DIRECTORIES` A semi-colon (``;``) separated string of
+                                absolute and relative (to the app root) paths
+                                to translation folders. Defaults to
+                                ``translations``.
+`BABEL_DOMAIN`                  The message domain used by the application.
+                                Defaults to ``messages``.
+=============================== =============================================
 
 For more complex applications you might want to have multiple applications
 for different users which is where selector functions come in handy.  The

flask_babel/__init__.py

@@ -59,9 +59,11 @@ class Babel(object):
     })
 
     def __init__(self, app=None, default_locale='en', default_timezone='UTC',
-                 date_formats=None, configure_jinja=True):
+                 default_domain='messages', date_formats=None,
+                 configure_jinja=True):
         self._default_locale = default_locale
         self._default_timezone = default_timezone
+        self._default_domain = default_domain
         self._date_formats = date_formats
         self._configure_jinja = configure_jinja
         self.app = app
@@ -83,6 +85,7 @@ def init_app(self, app):
 
         app.config.setdefault('BABEL_DEFAULT_LOCALE', self._default_locale)
         app.config.setdefault('BABEL_DEFAULT_TIMEZONE', self._default_timezone)
+        app.config.setdefault('BABEL_DOMAIN', self._default_domain)
         if self._date_formats is None:
             self._date_formats = self.default_date_formats.copy()
 
@@ -186,6 +189,12 @@ def default_timezone(self):
         """
         return timezone(self.app.config['BABEL_DEFAULT_TIMEZONE'])
 
+    @property
+    def domain(self):
+        """The message domain for the translations as a string.
+        """
+        return self.app.config['BABEL_DOMAIN']
+
     @property
     def translation_directories(self):
         directories = self.app.config.get(
@@ -217,7 +226,8 @@ def get_translations():
             translations.merge(
                 support.Translations.load(
                     dirname,
-                    [get_locale()]
+                    [get_locale()],
+                    babel.domain
                 )
             )
 

tests/tests.py

@@ -53,6 +53,29 @@ def test_multiple_directories(self):
                 name='Peter'
             ) == 'Hallo Peter!'
 
+    def test_different_domain(self):
+        """
+        Ensure we can load translations from multiple directories.
+        """
+        b = babel.Babel()
+        app = flask.Flask(__name__)
+
+        app.config.update({
+            'BABEL_TRANSLATION_DIRECTORIES': 'translations_different_domain',
+            'BABEL_DEFAULT_LOCALE': 'de_DE',
+            'BABEL_DOMAIN': 'myapp'
+        })
+
+        b.init_app(app)
+
+        with app.test_request_context():
+            translations = b.list_translations()
+
+            assert(len(translations) == 1)
+            assert(str(translations[0]) == 'de')
+
+            assert gettext(u'Good bye') == 'Auf Wiedersehen'
+
 
 class DateFormattingTestCase(unittest.TestCase):
 

tests/translations_different_domain/de/LC_MESSAGES/myapp.mo

@@ -0,0 +1,37 @@
+# German translations for PROJECT.
+# Copyright (C) 2010 ORGANIZATION
+# This file is distributed under the same license as the PROJECT project.
+# FIRST AUTHOR <EMAIL@ADDRESS>, 2010.
+#
+msgid ""
+msgstr ""
+"Project-Id-Version: PROJECT VERSION\n"
+"Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
+"POT-Creation-Date: 2010-05-29 17:00+0200\n"
+"PO-Revision-Date: 2010-05-30 12:56+0200\n"
+"Last-Translator: Armin Ronacher <armin.ronacher@active-4.com>\n"
+"Language-Team: de <LL@li.org>\n"
+"Plural-Forms: nplurals=2; plural=(n != 1)\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=utf-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Generated-By: Babel 0.9.5\n"
+
+#: tests.py:94
+#, python-format
+msgid "Hello %(name)s!"
+msgstr "Hallo %(name)s!"
+
+#: tests.py:95 tests.py:96
+#, python-format
+msgid "%(num)s Apple"
+msgid_plural "%(num)s Apples"
+msgstr[0] "%(num)s Apfel"
+msgstr[1] "%(num)s Äpfel"
+
+#: tests.py:119
+msgid "Yes"
+msgstr "Ja"
+
+msgid "Good bye"
+msgstr "Auf Wiedersehen"

tests/translations_different_domain/de/LC_MESSAGES/myapp.po

@@ -0,0 +1,37 @@
+# Translations template for PROJECT.
+# Copyright (C) 2010 ORGANIZATION
+# This file is distributed under the same license as the PROJECT project.
+# FIRST AUTHOR <EMAIL@ADDRESS>, 2010.
+#
+#, fuzzy
+msgid ""
+msgstr ""
+"Project-Id-Version: PROJECT VERSION\n"
+"Report-Msgid-Bugs-To: EMAIL@ADDRESS\n"
+"POT-Creation-Date: 2010-05-30 12:56+0200\n"
+"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
+"Last-Translator: FULL NAME <EMAIL@ADDRESS>\n"
+"Language-Team: LANGUAGE <LL@li.org>\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=utf-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Generated-By: Babel 0.9.5\n"
+
+#: tests.py:94
+#, python-format
+msgid "Hello %(name)s!"
+msgstr ""
+
+#: tests.py:95 tests.py:96
+#, python-format
+msgid "%(num)s Apple"
+msgid_plural "%(num)s Apples"
+msgstr[0] ""
+msgstr[1] ""
+
+#: tests.py:119
+msgid "Yes"
+msgstr ""
+
+msgid "Good bye"
+msgstr ""