Automatically generate i18n javascript files for react-intl when the …

…serve starts up

CHANGELOG.md

@@ -8,6 +8,9 @@ Contributors: please follow the recommendations outlined at [keepachangelog.com]
 ### Fixed
 - Removed foreman as a dependency. [#678](https://github.com/shakacode/react_on_rails/pull/678) by [x2es](https://github.com/x2es).
 
+### Changed
+- Automatically generate __i18n__ javascript files for `react-intl` when the serve starts up. [#642](https://github.com/shakacode/react_on_rails/pull/642) by [JasonYCHuang](https://github.com/JasonYCHuang).
+
 ## [6.3.5] - 2017-1-6
 ### Fixed
 - The redux generator now creates a HelloWorld component that uses redux rather than local state. [#669](https://github.com/shakacode/react_on_rails/issues/669) by [justin808](https://github.com/justin808).

README.md

@@ -50,6 +50,7 @@ React on Rails integrates Facebook's [React](https://github.com/facebook/react)
     - [Installation Summary](#installation-summary)
     - [Initializer Configuration: config/initializers/react_on_rails.rb](#initializer-configuration)
     - [Including your React Component in your Rails Views](#including-your-react-component-in-your-rails-views)
+    - [I18n](#i18n)
 + [How it Works](#how-it-works)
     - [Client-Side Rendering vs. Server-Side Rendering](#client-side-rendering-vs-server-side-rendering)
     - [Building the Bundles](#building-the-bundles)
@@ -170,7 +171,15 @@ Configure the `config/initializers/react_on_rails.rb`. You can adjust some neces
     // inside your React component
     this.props.name // "Stranger"
   ```
-  
+
+### I18n
+
+You can enable the i18n functionality with [react-intl](https://github.com/yahoo/react-intl).
+
+React on Rails provides an option for automatic conversion of Rails `*.yml` locale files into `*.js` files for `react-intl`.
+
+See the [How to add I18n](docs/basics/i18n.md) for a summary of adding I18n.
+
 ## NPM
 All JavaScript in React On Rails is loaded from npm: [react-on-rails](https://www.npmjs.com/package/react-on-rails). To manually install this (you did not use the generator), assuming you have a standard configuration, run this command:
 
@@ -245,11 +254,6 @@ The `railsContext` has: (see implementation in file [react_on_rails_helper.rb](a
     pathname: uri.path, # /posts
     search: uri.query, # id=30&limit=5
 
-    # Locale settings
-    i18nLocale: I18n.locale,
-    i18nDefaultLocale: I18n.default_locale,
-    httpAcceptLanguage: request.env["HTTP_ACCEPT_LANGUAGE"],
-
     # Other
     serverSide: boolean # Are we being called on the server or client? NOTE, if you conditionally
      # render something different on the server than the client, then React will only show the
@@ -261,9 +265,6 @@ The `railsContext` has: (see implementation in file [react_on_rails_helper.rb](a
 ##### Needing the current url path for server rendering
 Suppose you want to display a nav bar with the current navigation link highlighted by the URL. When you server render the code, you will need to know the current URL/path if that is what you want your logic to be based on. The new `railsContext` has this information so the application of an "active" class can be done server side.
 
-##### Needing the I18n.locale
-Suppose you want to server render your react components with localization applied given the current Rails locale. The `railsContext` contains the I18n.locale.
-
 ##### Configuring different code for server side rendering
 Suppose you want to turn off animation when doing server side rendering. The `serverSide` value is just what you need.
 

docs/basics/i18n.md

@@ -0,0 +1,90 @@
+# How to add I18n
+
+Here's a summary of adding I18n functionality with React on Rails.
+
+You can refer to [react-webpack-rails-tutorial](https://github.com/shakacode/react-webpack-rails-tutorial) for a complete example.
+
+1. Add `react-intl` & `intl` to `client/package.json`, and remember to `bundle && npm install`.
+
+  ```js
+  "dependencies": {
+    ...
+    "intl": "^1.2.5",
+    "react-intl": "^2.1.5",
+    ...
+  }
+  ```
+
+2. In `client/webpack.client.base.config.js`, set `react-intl` as an entry point.
+
+  ```js
+  module.exports = {
+    ...
+    entry: {
+      ...
+      vendor: [
+        ...
+        'react-intl',
+      ],
+      ...
+  ```
+
+3. `react-intl` requires locale files in json format. React on Rails will help you to generate or update `translations.js` & `default.js` automatically after you configured the following settings.
+  
+  > `translations.js`: All your locales in json format.
+  >
+  > `default.js`: Default settings in json format.
+  >
+  > You can add them to `.gitignore` and `.eslintignore`.
+  
+  Update settings in `config/initializers/react_on_rails.rb` to what you need:
+
+  ```ruby
+  # Replace the following line to the location where you keep translation.js & default.js.
+  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.
+
+  ```js
+  module YourModule
+    class Application < Rails::Application
+      ...
+      config.after_initialize do
+        ReactOnRails::LocalesToJs.new
+      end
+    end
+  end
+  ```
+
+5. In React, you need to initialize `react-intl`, and set parameters for it.
+
+  ```js
+  ...
+  import { addLocaleData } from 'react-intl';
+  import en from 'react-intl/locale-data/en';
+  import de from 'react-intl/locale-data/de';
+  import { translations } from 'path_to/i18n/translations';
+  import { defaultLocale } from 'path_to/i18n/default';
+  ...
+  // Initizalize all locales for react-intl.
+  addLocaleData([...en, ...de]);
+  ...
+  // set locale and messages for IntlProvider.
+  const locale = method_to_get_current_locale() || defaultLocale;
+  const messages = translations[locale];
+  ...
+  return (
+    <IntlProvider locale={locale} key={locale} messages={messages}>
+      <CommentScreen {...{ actions, data }} />
+    </IntlProvider>
+  )
+  ```
+  ```js
+  // In your component.
+  import { defaultMessages } from 'path_to/i18n/default';
+  ...
+  return (
+    { formatMessage(defaultMessages.yourLocaleKeyInCamelCase) }
+  )
+  ```

lib/generators/react_on_rails/templates/base/base/config/initializers/react_on_rails.rb.tt

@@ -59,6 +59,12 @@ ReactOnRails.configure do |config|
   config.server_renderer_pool_size = 1 # increase if you're on JRuby
   config.server_renderer_timeout = 20 # seconds
 
+  ################################################################################
+  # I18N OPTIONS
+  ################################################################################
+  # Replace the following line to the location where you keep translation.js & default.js.
+  config.i18n_dir = Rails.root.join("client", "app", "libs", "i18n")
+
   ################################################################################
   # MISCELLANEOUS OPTIONS
   ################################################################################

lib/react_on_rails.rb

@@ -16,3 +16,4 @@
 require "react_on_rails/test_helper/webpack_assets_status_checker"
 require "react_on_rails/test_helper/ensure_assets_compiled"
 require "react_on_rails/test_helper/node_process_launcher"
+require "react_on_rails/locales_to_js"

lib/react_on_rails/configuration.rb

@@ -72,6 +72,7 @@ def self.configuration
       server_render_method: "",
       symlink_non_digested_assets_regex: /\.(png|jpg|jpeg|gif|tiff|woff|ttf|eot|svg|map)/,
       npm_build_test_command: "",
+      i18n_dir: "",
       npm_build_production_command: ""
     )
   end
@@ -84,6 +85,7 @@ class Configuration
                   :skip_display_none, :generated_assets_dirs, :generated_assets_dir,
                   :webpack_generated_files, :rendering_extension, :npm_build_test_command,
                   :npm_build_production_command,
+                  :i18n_dir,
                   :server_render_method, :symlink_non_digested_assets_regex
 
     def initialize(server_bundle_js_file: nil, prerender: nil, replay_console: nil,
@@ -94,12 +96,14 @@ def initialize(server_bundle_js_file: nil, prerender: nil, replay_console: nil,
                    generated_assets_dir: nil, webpack_generated_files: nil,
                    rendering_extension: nil, npm_build_test_command: nil,
                    npm_build_production_command: nil,
+                   i18n_dir: nil,
                    server_render_method: nil, symlink_non_digested_assets_regex: nil)
       self.server_bundle_js_file = server_bundle_js_file
       self.generated_assets_dirs = generated_assets_dirs
       self.generated_assets_dir = generated_assets_dir
       self.npm_build_test_command = npm_build_test_command
       self.npm_build_production_command = npm_build_production_command
+      self.i18n_dir = i18n_dir
 
       self.prerender = prerender
       self.replay_console = replay_console

lib/react_on_rails/locales_to_js.rb

@@ -0,0 +1,119 @@
+require "erb"
+
+module ReactOnRails
+  class LocalesToJs
+    def initialize
+      return unless obsolete?
+      @translations, @defaults = generate_translations
+      convert
+    end
+
+    private
+
+    def obsolete?
+      return true if exist_js_files.empty?
+      js_files_are_outdated
+    end
+
+    def exist_js_files
+      @exist_js_files ||= js_files.select(&File.method(:exist?))
+    end
+
+    def js_files_are_outdated
+      latest_yml = locale_files.map(&File.method(:mtime)).max
+      earliest_js = exist_js_files.map(&File.method(:mtime)).min
+      latest_yml > earliest_js
+    end
+
+    def js_file_names
+      %w(translations default)
+    end
+
+    def js_files
+      @js_files ||= js_file_names.map { |n| js_file(n) }
+    end
+
+    def js_file(name)
+      "#{i18n_dir}/#{name}.js"
+    end
+
+    def locale_files
+      @locale_files ||= Rails.application.config.i18n.load_path
+    end
+
+    def i18n_dir
+      @i18n_dir ||= ReactOnRails.configuration.i18n_dir
+    end
+
+    def default_locale
+      @default_locale ||= I18n.default_locale.to_s || "en"
+    end
+
+    def convert
+      js_file_names.each do |name|
+        template = send("template_#{name}")
+        path = js_file(name)
+        generate_js_file(template, path)
+      end
+    end
+
+    def generate_js_file(template, path)
+      result = ERB.new(template).result()
+      File.open(path, "w") do |f|
+        f.write(result)
+      end
+    end
+
+    def generate_translations
+      translations = {}
+      defaults = {}
+      locale_files.each do |f|
+        translation = YAML.load(File.open(f))
+        key = translation.keys[0]
+        val = flatten(translation[key])
+        translations = translations.deep_merge(key => val)
+        defaults = defaults.deep_merge(flatten_defaults(val)) if key == default_locale
+      end
+      [translations.to_json, defaults.to_json]
+    end
+
+    def format(input)
+      input.to_s.tr(".", "_").camelize(:lower).to_sym
+    end
+
+    def flatten_defaults(val)
+      flatten(val).each_with_object({}) do |(k, v), h|
+        key = format(k)
+        h[key] = { id: k, defaultMessage: v }
+      end
+    end
+
+    def flatten(translations)
+      translations.each_with_object({}) do |(k, v), h|
+        if v.is_a? Hash
+          flatten(v).map { |hk, hv| h["#{k}.#{hk}".to_sym] = hv }
+        else
+          h[k] = v
+        end
+      end
+    end
+
+    def template_translations
+      <<-JS
+export const translations = #{@translations};
+      JS
+    end
+
+    def template_default
+      <<-JS
+import { defineMessages } from 'react-intl';
+
+const defaultLocale = \'#{default_locale}\';
+
+const defaultMessages = defineMessages(#{@defaults});
+
+export { defaultMessages, defaultLocale };
+      JS
+    end
+  end
+end

spec/dummy/config/initializers/react_on_rails.rb

@@ -71,6 +71,12 @@ def self.custom_context(view_context)
   config.server_renderer_pool_size = 1 # increase if you're on JRuby
   config.server_renderer_timeout = 20 # seconds
 
+  ################################################################################
+  # I18N OPTIONS
+  ################################################################################
+  # Replace the following line to the location where you keep translation.js & default.js.
+  config.i18n_dir = Rails.root.join("client", "app", "libs", "i18n")
+
   ################################################################################
   # MISCELLANEOUS OPTIONS
   ################################################################################

spec/react_on_rails/fixtures/i18n/locales/de.yml

@@ -0,0 +1,2 @@
+de:
+  hello: "Hallo welt"

spec/react_on_rails/fixtures/i18n/locales/en.yml

@@ -0,0 +1,2 @@
+en:
+  hello: "Hello world"

spec/react_on_rails/locales_to_js_spec.rb

@@ -0,0 +1,53 @@
+require_relative "spec_helper"
+require "tmpdir"
+
+module ReactOnRails
+  RSpec.describe LocalesToJs do
+    let(:i18n_dir) { Pathname.new(Dir.mktmpdir) }
+    let(:locale_dir) { File.expand_path("../fixtures/i18n/locales", __FILE__) }
+    let(:translations_path) { "#{i18n_dir}/translations.js" }
+    let(:default_path) { "#{i18n_dir}/default.js" }
+    let(:en_path) { "#{locale_dir}/en.yml" }
+
+    before do
+      allow_any_instance_of(ReactOnRails::LocalesToJs).to receive(:locale_files).and_return(Dir["#{locale_dir}/*"])
+      ReactOnRails.configure do |config|
+        config.i18n_dir = i18n_dir
+      end
+    end
+
+    context "with obsolete js files" do
+      before do
+        FileUtils.touch(translations_path, mtime: Time.now - 1.year)
+        FileUtils.touch(en_path, mtime: Time.now)
+      end
+
+      it "updates files" do
+        ReactOnRails::LocalesToJs.new
+
+        translations = File.read(translations_path)
+        default = File.read(default_path)
+        expect(translations).to include("{\"hello\":\"Hello world\"")
+        expect(translations).to include("{\"hello\":\"Hallo welt\"")
+        expect(default).to include("const defaultLocale = 'en';")
+        expect(default).to include("{\"hello\":{\"id\":\"hello\",\"defaultMessage\":\"Hello world\"}}")
+
+        expect(File.mtime(translations_path)).to be >= File.mtime(en_path)
+      end
+    end
+
+    context "with up-to-date js files" do
+      before do
+        ReactOnRails::LocalesToJs.new
+      end
+
+      it "doesn't update files" do
+        mt = File.mtime(translations_path)
+        sleep 1
+
+        ReactOnRails::LocalesToJs.new
+        expect(File.mtime(translations_path)).to eq(mt)
+      end
+    end
+  end
+end