Ruby I18n

Ruby internationalization and localization (i18n) solution.

Currently maintained by @radar.

Usage

Rails

You will most commonly use this library within a Rails app.

We support Rails versions from 6.0 and up.

See the Rails Guide for an example of its usage.

Ruby (without Rails)

We support Ruby versions from 3.0 and up.

If you want to use this library without Rails, you can simply add i18n to your Gemfile:

gem 'i18n'

Then configure I18n with some translations, and a default locale:

I18n.load_path += Dir[File.expand_path("config/locales") + "/*.yml"]
I18n.default_locale = :en # (note that `en` is already the default!)

A simple translation file in your project might live at config/locales/en.yml and look like:

en:
  test: "This is a test"

You can then access this translation by doing:

I18n.t(:test)

You can switch locales in your project by setting I18n.locale to a different value:

I18n.locale = :de
I18n.t(:test) # => "Dies ist ein Test"

Features

Translation and localization
Interpolation of values to translations
Pluralization (CLDR compatible)
Customizable transliteration to ASCII
Flexible defaults
Bulk lookup
Lambdas as translation data
Custom key/scope separator
Custom exception handlers
Extensible architecture with a swappable backend

Pluggable Features

Cache
Pluralization: lambda pluralizers stored as translation data
Locale fallbacks, RFC4647 compliant (optionally: RFC4646 locale validation)
Gettext support
Translation metadata

Alternative Backend

Chain
ActiveRecord (optionally: ActiveRecord::Missing and ActiveRecord::StoreProcs)
KeyValue (uses active_support/json and cannot store procs)

For more information and lots of resources see the 'Resources' page on the wiki.

Tests

You can run tests both with

rake test or just rake
run any test file directly, e.g. ruby -Ilib:test test/api/simple_test.rb

You can run all tests against all Gemfiles with

ruby test/run_all.rb

The structure of the test suite is a bit unusual as it uses modules to reuse particular tests in different test cases.

The reason for this is that we need to enforce the I18n API across various combinations of extensions. E.g. the Simple backend alone needs to support the same API as any combination of feature and/or optimization modules included to the Simple backend. We test this by reusing the same API definition (implemented as test methods) in test cases with different setups.

You can find the test cases that enforce the API in test/api. And you can find the API definition test methods in test/api/tests.

All other test cases (e.g. as defined in test/backend, test/core_ext) etc. follow the usual test setup and should be easy to grok.

Contributors

@radar
@carlosantoniodasilva
@josevalim
@knapo
@tigrish
and many more

License

MIT License. See the included MIT-LICENSE file.