can use a translation object for the given language and the current site (app_dir)

written by Benjamin Dauvergne
fix #477

wcs/qommon/publisher.py

@@ -94,6 +94,7 @@ class QommonPublisher(Publisher):
     auto_create_appdir = True
     missing_appdir_redirect = None
     use_sms_feature = False
+    app_translations = dict()
 
     def get_root_url(self):
         return self.get_request().environ['SCRIPT_NAME'] + '/'
@@ -257,11 +258,21 @@ class QommonPublisher(Publisher):
             return output
         return template.decorate(output, response)
 
+    def get_translation(self, lang):
+        '''Retrieve a translation object for the given language and the current site.'''
+        app_translation_path = os.path.join(self.app_dir, '%s.mo' % lang)
+        if os.path.exists(app_translation_path):
+            trans = gettext.GNUTranslations(file(app_translation_path))
+            trans.add_fallback(self.translations[lang])
+        else:
+            trans = self.translations[lang]
+        return trans
+
     def install_lang(self, lang = None):
         if lang is None or not self.translations.has_key(lang):
             gettext.install(self.APP_NAME) # will use environment variable to get language
         else:
-            self.translations[lang].install()
+            self.get_translation(lang).install()
         _1 = _
         __builtin__.__dict__['_'] = lambda x: unicode(_1(str(x)), 'utf-8').encode(self.site_charset)
         __builtin__.__dict__['_1'] = _1