I18n support for plugins

Rails will now automatically add locale files found in any engine's locale
directory to the I18n.load_path (i.e. files that match the glob pattern
"config/locales/**/*.{rb,yml}" relative to engine directories).

[#2325 state:committed]

Signed-off-by: Jeremy Kemper <jeremy@bitsweat.net>

2 files changed, 19 insertions, 0 deletions

diff --git a/railties/lib/rails/plugin.rb b/railties/lib/rails/plugin.rb
index 49ec5c7fba..1c0af6411a 100644
--- a/railties/lib/rails/plugin.rb
+++ b/railties/lib/rails/plugin.rb
@@ -71,6 +71,10 @@ module Rails
       File.exist?(routing_file)
     end
 
+    # Returns true if there is any localization file in locale_path
+    def localized?
+      locale_files.any?
+    end
 
     def view_path
       File.join(directory, 'app', 'views')
@@ -87,6 +91,14 @@ module Rails
     def routing_file
       File.join(directory, 'config', 'routes.rb')
     end
+
+    def locale_path
+      File.join(directory, 'config', 'locales')
+    end
+
+    def locale_files
+      Dir[ File.join(locale_path, '*.{rb,yml}') ]
+    end
     
 
     private
diff --git a/railties/lib/rails/plugin/loader.rb b/railties/lib/rails/plugin/loader.rb
index 7ea9c7c0f3..9e2c3c7b03 100644
--- a/railties/lib/rails/plugin/loader.rb
+++ b/railties/lib/rails/plugin/loader.rb
@@ -73,6 +73,7 @@ module Rails
         def configure_engines
           if engines.any?
             add_engine_routing_configurations
+            add_engine_locales
             add_engine_controller_paths
             add_engine_view_paths
           end
@@ -84,6 +85,12 @@ module Rails
           end
         end
 
+        def add_engine_locales
+          # reverse it such that the last engine can overwrite translations from the first, like with routes
+          locale_files = engines.select(&:localized?).collect(&:locale_files).reverse.flatten
+          I18n.load_path += locale_files - I18n.load_path
+        end
+
         def add_engine_controller_paths
           ActionController::Routing.controller_paths += engines.collect {|engine| engine.controller_path }
         end