update docs

CHANGELOG.md

@@ -6,6 +6,9 @@ Contributors: please follow the recommendations outlined at [keepachangelog.com]
 ## [Unreleased]
 *Please add entries here for your pull requests.*
 
+### Added
+- Allow using rake task to generate javascript locale files. [#717](https://github.com/shakacode/react_on_rails/pull/717) by [JasonYCHuang](https://github.com/JasonYCHuang).
+
 ## [6.6.0] - 2017-02-18
 ### Added
 - Switched to yarn! [#715](https://github.com/shakacode/react_on_rails/pull/715) by [squadette](https://github.com/squadette).

docs/basics/i18n.md

@@ -44,17 +44,32 @@ You can refer to [react-webpack-rails-tutorial](https://github.com/shakacode/rea
   config.i18n_dir = Rails.root.join("PATH_TO", "YOUR_JS_I18N_FOLDER")
   ```
 
-  Add following lines to `config/application.rb`, this will help you to generate `translations.js` & `default.js` automatically when you starts the server.
+4. Javascript locale files must be generated before `npm build`. 
 
-  ```js
-  module YourModule
-    class Application < Rails::Application
+  To ensure this:
+  
+  For __test__ and __production__, add `pre-hook` into `client/package.json` to invoke build-in rake task.
+
+  ```javascript
+  {
+    ...
+    "scripts": {
+      ...
+      // Assume that the following two lines are your original build script.
+      "build:test": "webpack --config webpack.config.js",
+      "build:production": "NODE_ENV=production webpack --config webpack.config.js",
+      // You need to add pre-hook for them.
+      "prebuild:test": "rake react_on_rails:locale",
+      "prebuild:production": "rake react_on_rails:locale",
       ...
-      config.after_initialize do
-        ReactOnRails::LocalesToJs.new
-      end
-    end
-  end
+    }
+  }
+  ```
+
+  For __dev__, add `bundle exec rake react_on_rails:locale` to `Procfile.dev` before `npm build`. 
+
+  ```ruby
+  client: sh -c 'rm app/assets/webpack/* || true && bundle exec rake react_on_rails:locale && cd client && npm run build:development'
   ```
 
 5. In React, you need to initialize `react-intl`, and set parameters for it.