Export i18n translations to JSON.
A perfect fit if you want to export translations to JavaScript.

Oh, you don't use Ruby? No problem! You can still use i18n-js
and the companion JavaScript package.

Installation

gem install i18n-js

Or add the following line to your project's Gemfile:

gem "i18n-js", "~> 4.0.0.alpha1"

Usage

About patterns:

Patterns can use * as a wildcard and can appear more than once.
- * will include everything
- *.messages.*
Patterns starting with ! are excluded.
- !*.activerecord.* will exclude all ActiveRecord translations.

The config file:

---
translations:
  - file: app/frontend/locales/en.json
    patterns:
      - "*"
      - "!*.activerecord"
      - "!*.errors"
      - "!*.number.nth"

  - file: app/frontend/locales/:locale.json
    patterns:
      - "*"

The Ruby API:

require "i18n-js"

I18nJS.call(config_file: "config/i18n.yml")
I18nJS.call(config: config)

The CLI API:

$ i18n init --config config/i18n.yml
$ i18n export --config config/i18n.yml --require config/environment.rb

By default, i18n will use config/i18n.yml and config/environment.rb as the configuration files. If you don't have these files, then you'll need to specify both --config and --require.

Automatically export translations

Using watchman

Create a script at bin/i18n-watch.

#!/usr/bin/env bash

root=`pwd`

watchman watch-del "$root"
watchman watch-project "$root"
watchman trigger-del "$root" i18n

watchman -j <<-JSON
[
  "trigger",
  "$root",
  {
    "name": "i18n",
    "expression": [
      "anyof",
      ["match", "config/locales/**/*.yml", "wholename"],
      ["match", "config/i18n.yml", "wholename"]
    ],
    "command": ["i18n", "export"]
  }
]
JSON

# If you're running this through Foreman,
# the uncomment the following lines:
# while true; do
#   sleep 1
# done

Make it executable with chmod +x bin/i18n-watch. To watch for changes, run ./bin/i18n-watch. If you're using Foreman, make sure you uncommented the lines that keep the process running (while..), and add something like the following line to your Procfile:

i18n: ./bin/i18n-watch

Using guard

Install guard and guard-compat. Then create a Guardfile with the following configuration:

guard(:"i18n-js",
      run_on_start: true,
      config_file: "./config/i18n.yml",
      require_file: "./config/environment.rb") do
  watch(%r{^(app|config)/locales/.+\.(yml|po)$})
  watch(%r{^config/i18n.yml$})
  watch("Gemfile")
end

If your files are located in a different path, remember to configure file paths accordingly.

Now you can run guard start -i.

Using listen

Create a file under config/initializers/i18n.rb with the following content:

Rails.application.config.after_initialize do
  require "i18n-js/listen"
  I18nJS.listen
end

The code above will watch for changes based on config/i18n.yml and config/locales. You can customize these options with I18nJS.listen(config_file: "config/i18n.yml", locales_dir: "config/locales").

Integrating with your frontend

You're done exporting files, now what? Well, go to i18n to discover how to use the NPM package that loads all the exported translation.

FAQ

How can I export translations without having a database around?

Some people may have a build process using something like Docker that don't necessarily have a database available. In this case, you may define your own loading file by using something like i18n export --require ./config/i18n_export.rb, where i18n_export.rb may look like this:

# frozen_string_literal: true

require "bundler/setup"
require "rails"
require "active_support/railtie"
require "action_view/railtie"

I18n.load_path += Dir["./config/locales/**/*.yml"]

Notice that you may not need to load ActiveSupport and ActionView lines, or even may need to add additional requires for other libs. With this approach you have full control on what's going to be loaded.