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diff --git a/guides/source/i18n.md b/guides/source/i18n.md index 6c8706bc13..78e5f27448 100644 --- a/guides/source/i18n.md +++ b/guides/source/i18n.md @@ -1,4 +1,4 @@ -**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON http://guides.rubyonrails.org.** +**DO NOT READ THIS FILE ON GITHUB, GUIDES ARE PUBLISHED ON https://guides.rubyonrails.org.** Rails Internationalization (I18n) API ===================================== @@ -11,7 +11,7 @@ So, in the process of _internationalizing_ your Rails application you have to: * Ensure you have support for i18n. * Tell Rails where to find locale dictionaries. -* Tell Rails how to set, preserve and switch locales. +* Tell Rails how to set, preserve, and switch locales. In the process of _localizing_ your application you'll probably want to do the following three things: @@ -42,6 +42,8 @@ Internationalization is a complex problem. Natural languages differ in so many w As part of this solution, **every static string in the Rails framework** - e.g. Active Record validation messages, time and date formats - **has been internationalized**. _Localization_ of a Rails application means defining translated values for these strings in desired languages. +To localize store and update _content_ in your application (e.g. translate blog posts), see the [Translating model content](#translating-model-content) section. + ### The Overall Architecture of the Library Thus, the Ruby I18n gem is split into two parts: @@ -75,8 +77,8 @@ There are also attribute readers and writers for the following attributes: load_path # Announce your custom translation files locale # Get and set the current locale default_locale # Get and set the default locale -available_locales # Whitelist locales available for the application -enforce_available_locales # Enforce locale whitelisting (true or false) +available_locales # Permitted locales available for the application +enforce_available_locales # Enforce locale permission (true or false) exception_handler # Use a different exception_handler backend # Use a different backend ``` @@ -105,7 +107,7 @@ This means, that in the `:en` locale, the key _hello_ will map to the _Hello wor The I18n library will use **English** as a **default locale**, i.e. if a different locale is not set, `:en` will be used for looking up translations. -NOTE: The i18n library takes a **pragmatic approach** to locale keys (after [some discussion](http://groups.google.com/group/rails-i18n/browse_thread/thread/14dede2c7dbe9470/80eec34395f64f3c?hl=en)), including only the _locale_ ("language") part, like `:en`, `:pl`, not the _region_ part, like `:en-US` or `:en-GB`, which are traditionally used for separating "languages" and "regional setting" or "dialects". Many international applications use only the "language" element of a locale such as `:cs`, `:th` or `:es` (for Czech, Thai and Spanish). However, there are also regional differences within different language groups that may be important. For instance, in the `:en-US` locale you would have $ as a currency symbol, while in `:en-GB`, you would have £. Nothing stops you from separating regional and other settings in this way: you just have to provide full "English - United Kingdom" locale in a `:en-GB` dictionary. Few gems such as [Globalize3](https://github.com/globalize/globalize) may help you implement it. +NOTE: The i18n library takes a **pragmatic approach** to locale keys (after [some discussion](https://groups.google.com/forum/#!topic/rails-i18n/FN7eLH2-lHA)), including only the _locale_ ("language") part, like `:en`, `:pl`, not the _region_ part, like `:en-US` or `:en-GB`, which are traditionally used for separating "languages" and "regional setting" or "dialects". Many international applications use only the "language" element of a locale such as `:cs`, `:th`, or `:es` (for Czech, Thai, and Spanish). However, there are also regional differences within different language groups that may be important. For instance, in the `:en-US` locale you would have $ as a currency symbol, while in `:en-GB`, you would have £. Nothing stops you from separating regional and other settings in this way: you just have to provide full "English - United Kingdom" locale in a `:en-GB` dictionary. The **translations load path** (`I18n.load_path`) is an array of paths to files that will be loaded automatically. Configuring this path allows for customization of translations directory structure and file naming scheme. @@ -126,7 +128,7 @@ The load path must be specified before any translations are looked up. To change # Where the I18n library should search for translation files I18n.load_path += Dir[Rails.root.join('lib', 'locale', '*.{rb,yml}')] -# Whitelist locales available for the application +# Permitted locales available for the application I18n.available_locales = [:en, :pt] # Set default locale to something other than :en @@ -310,10 +312,10 @@ In general, this approach is far less reliable than using the language header an #### Storing the Locale from the Session or Cookies -WARNING: You may be tempted to store the chosen locale in a _session_ or a *cookie*. However, **do not do this**. The locale should be transparent and a part of the URL. This way you won't break people's basic assumptions about the web itself: if you send a URL to a friend, they should see the same page and content as you. A fancy word for this would be that you're being [*RESTful*](http://en.wikipedia.org/wiki/Representational_State_Transfer). Read more about the RESTful approach in [Stefan Tilkov's articles](http://www.infoq.com/articles/rest-introduction). Sometimes there are exceptions to this rule and those are discussed below. +WARNING: You may be tempted to store the chosen locale in a _session_ or a *cookie*. However, **do not do this**. The locale should be transparent and a part of the URL. This way you won't break people's basic assumptions about the web itself: if you send a URL to a friend, they should see the same page and content as you. A fancy word for this would be that you're being [*RESTful*](https://en.wikipedia.org/wiki/Representational_State_Transfer). Read more about the RESTful approach in [Stefan Tilkov's articles](https://www.infoq.com/articles/rest-introduction). Sometimes there are exceptions to this rule and those are discussed below. Internationalization and Localization ------------------------------------ +------------------------------------- OK! Now you've initialized I18n support for your Ruby on Rails application and told it which locale to use and how to preserve it between requests. @@ -371,7 +373,7 @@ end ```html+erb # app/views/home/index.html.erb -<h1><%=t :hello_world %></h1> +<h1><%= t :hello_world %></h1> <p><%= flash[:notice] %></p> ``` @@ -416,7 +418,7 @@ If your translations are stored in YAML files, certain keys must be escaped. The Examples: -```erb +```yaml # config/locales/en.yml en: success: @@ -430,12 +432,12 @@ en: ``` ```ruby -I18n.t 'success.true' # => 'True!' -I18n.t 'success.on' # => 'On!' +I18n.t 'success.true' # => 'True!' +I18n.t 'success.on' # => 'On!' I18n.t 'success.false' # => 'False!' I18n.t 'failure.false' # => Translation Missing -I18n.t 'failure.off' # => Translation Missing -I18n.t 'failure.true' # => Translation Missing +I18n.t 'failure.off' # => Translation Missing +I18n.t 'failure.true' # => Translation Missing ``` ### Passing Variables to Translations @@ -502,7 +504,7 @@ OK! Now let's add a timestamp to the view, so we can demo the **date/time locali ```erb # app/views/home/index.html.erb -<h1><%=t :hello_world %></h1> +<h1><%= t :hello_world %></h1> <p><%= flash[:notice] %></p> <p><%= l Time.now, format: :short %></p> ``` @@ -594,7 +596,7 @@ Covered are features like these: ### Looking up Translations -#### Basic Lookup, Scopes and Nested Keys +#### Basic Lookup, Scopes, and Nested Keys Translations are looked up by keys which can be both Symbols or Strings, so these calls are equivalent: @@ -701,9 +703,11 @@ end ### Pluralization -In English there are only one singular and one plural form for a given string, e.g. "1 message" and "2 messages". Other languages ([Arabic](http://www.unicode.org/cldr/charts/latest/supplemental/language_plural_rules.html#ar), [Japanese](http://www.unicode.org/cldr/charts/latest/supplemental/language_plural_rules.html#ja), [Russian](http://www.unicode.org/cldr/charts/latest/supplemental/language_plural_rules.html#ru) and many more) have different grammars that have additional or fewer [plural forms](http://cldr.unicode.org/index/cldr-spec/plural-rules). Thus, the I18n API provides a flexible pluralization feature. +In many languages — including English — there are only two forms, a singular and a plural, for +a given string, e.g. "1 message" and "2 messages". Other languages ([Arabic](http://www.unicode.org/cldr/charts/latest/supplemental/language_plural_rules.html#ar), [Japanese](http://www.unicode.org/cldr/charts/latest/supplemental/language_plural_rules.html#ja), [Russian](http://www.unicode.org/cldr/charts/latest/supplemental/language_plural_rules.html#ru) and many more) have different grammars that have additional or fewer [plural forms](http://cldr.unicode.org/index/cldr-spec/plural-rules). Thus, the I18n API provides a flexible pluralization feature. -The `:count` interpolation variable has a special role in that it both is interpolated to the translation and used to pick a pluralization from the translations according to the pluralization rules defined by CLDR: +The `:count` interpolation variable has a special role in that it both is interpolated to the translation and used to pick a pluralization from the translations according to the pluralization rules defined in the +pluralization backend. By default, only the English pluralization rules are applied. ```ruby I18n.backend.store_translations :en, inbox: { @@ -733,6 +737,22 @@ The translation denoted as `:one` is regarded as singular, and the `:other` is u If the lookup for the key does not return a Hash suitable for pluralization, an `I18n::InvalidPluralizationData` exception is raised. +#### Locale-specific rules + +The I18n gem provides a Pluralization backend that can be used to enable locale-specific rules. Include it +to the Simple backend, then add the localized pluralization algorithms to translation store, as `i18n.plural.rule`. + +```ruby +I18n::Backend::Simple.include(I18n::Backend::Pluralization) +I18n.backend.store_translations :pt, i18n: { plural: { rule: lambda { |n| [0, 1].include?(n) ? :one : :other } } } +I18n.backend.store_translations :pt, apples: { one: 'one or none', other: 'more than one' } + +I18n.t :apples, count: 0, locale: :pt +# => 'one or none' +``` + +Alternatively, the separate gem [rails-i18n](https://github.com/svenfuchs/rails-i18n) can be used to provide a fuller set of locale-specific pluralization rules. + ### Setting and Passing a Locale The locale can be either set pseudo-globally to `I18n.locale` (which uses `Thread.current` like, e.g., `Time.zone`) or can be passed as an option to `#translate` and `#localize`. @@ -809,14 +829,14 @@ For example when you add the following translations: en: activerecord: models: - user: Dude + user: Customer attributes: user: login: "Handle" # will translate User attribute "login" as "Handle" ``` -Then `User.model_name.human` will return "Dude" and `User.human_attribute_name("login")` will return "Handle". +Then `User.model_name.human` will return "Customer" and `User.human_attribute_name("login")` will return "Handle". You can also set a plural form for model names, adding as following: @@ -825,11 +845,11 @@ en: activerecord: models: user: - one: Dude - other: Dudes + one: Customer + other: Customers ``` -Then `User.model_name.human(count: 2)` will return "Dudes". With `count: 1` or without params will return "Dude". +Then `User.model_name.human(count: 2)` will return "Customers". With `count: 1` or without params will return "Customer". In the event you need to access nested attributes within a given model, you should nest these under `model/attribute` at the model level of your translation file: @@ -837,12 +857,12 @@ In the event you need to access nested attributes within a given model, you shou en: activerecord: attributes: - user/gender: - female: "Female" - male: "Male" + user/role: + admin: "Admin" + contributor: "Contributor" ``` -Then `User.human_attribute_name("gender.female")` will return "Female". +Then `User.human_attribute_name("role.admin")` will return "Admin". NOTE: If you are using a class which includes `ActiveModel` and does not inherit from `ActiveRecord::Base`, replace `activerecord` with `activemodel` in the above key paths. @@ -959,7 +979,7 @@ en: ``` NOTE: In order to use this helper, you need to install [DynamicForm](https://github.com/joelmoss/dynamic_form) -gem by adding this line to your Gemfile: `gem 'dynamic_form'`. +gem by adding this line to your `Gemfile`: `gem 'dynamic_form'`. ### Translations for Action Mailer E-Mail Subjects @@ -1032,7 +1052,7 @@ The Simple backend shipped with Active Support allows you to store translations For example a Ruby Hash providing translations can look like this: -```yaml +```ruby { pt: { foo: { @@ -1081,13 +1101,11 @@ Customize your I18n Setup For several reasons the Simple backend shipped with Active Support only does the "simplest thing that could possibly work" _for Ruby on Rails_[^3] ... which means that it is only guaranteed to work for English and, as a side effect, languages that are very similar to English. Also, the simple backend is only capable of reading translations but cannot dynamically store them to any format. -That does not mean you're stuck with these limitations, though. The Ruby I18n gem makes it very easy to exchange the Simple backend implementation with something else that fits better for your needs. E.g. you could exchange it with Globalize's Static backend: +That does not mean you're stuck with these limitations, though. The Ruby I18n gem makes it very easy to exchange the Simple backend implementation with something else that fits better for your needs, by passing a backend instance to the `I18n.backend=` setter. -```ruby -I18n.backend = Globalize::Backend::Static.new -``` +For example, you can replace the Simple backend with the the Chain backend to chain multiple backends together. This is useful when you want to use standard translations with a Simple backend but store custom application translations in a database or other backends. -You can also use the Chain backend to chain multiple backends together. This is useful when you want to use standard translations with a Simple backend but store custom application translations in a database or other backends. For example, you could use the Active Record backend and fall back to the (default) Simple backend: +With the Chain backend, you could use the Active Record backend and fall back to the (default) Simple backend: ```ruby I18n.backend = I18n::Backend::Chain.new(I18n::Backend::ActiveRecord.new, I18n.backend) @@ -1148,28 +1166,37 @@ To do so, the helper forces `I18n#translate` to raise exceptions no matter what I18n.t :foo, raise: true # always re-raises exceptions from the backend ``` +Translating Model Content +------------------------- + +The I18n API described in this guide is primarily intended for translating interface strings. If you are looking to translate model content (e.g. blog posts), you will need a different solution to help with this. + +Several gems can help with this: + +* [Globalize](https://github.com/globalize/globalize): Store translations on separate translation tables, one for each translated model +* [Mobility](https://github.com/shioyama/mobility): Provides support for storing translations in many formats, including translation tables, json columns (Postgres), etc. +* [Traco](https://github.com/barsoom/traco): Translatable columns for Rails 3 and 4, stored in the model table itself + Conclusion ---------- At this point you should have a good overview about how I18n support in Ruby on Rails works and are ready to start translating your project. -If you want to discuss certain portions or have questions, please sign up to the [rails-i18n mailing list](http://groups.google.com/group/rails-i18n). - Contributing to Rails I18n -------------------------- I18n support in Ruby on Rails was introduced in the release 2.2 and is still evolving. The project follows the good Ruby on Rails development tradition of evolving solutions in gems and real applications first, and only then cherry-picking the best-of-breed of most widely useful features for inclusion in the core. -Thus we encourage everybody to experiment with new ideas and features in gems or other libraries and make them available to the community. (Don't forget to announce your work on our [mailing list](http://groups.google.com/group/rails-i18n)!) +Thus we encourage everybody to experiment with new ideas and features in gems or other libraries and make them available to the community. (Don't forget to announce your work on our [mailing list](https://groups.google.com/forum/#!forum/rails-i18n)!) -If you find your own locale (language) missing from our [example translations data](https://github.com/svenfuchs/rails-i18n/tree/master/rails/locale) repository for Ruby on Rails, please [_fork_](https://github.com/guides/fork-a-project-and-submit-your-modifications) the repository, add your data and send a [pull request](https://help.github.com/articles/about-pull-requests/). +If you find your own locale (language) missing from our [example translations data](https://github.com/svenfuchs/rails-i18n/tree/master/rails/locale) repository for Ruby on Rails, please [_fork_](https://github.com/guides/fork-a-project-and-submit-your-modifications) the repository, add your data, and send a [pull request](https://help.github.com/articles/about-pull-requests/). Resources --------- -* [Google group: rails-i18n](http://groups.google.com/group/rails-i18n) - The project's mailing list. +* [Google group: rails-i18n](https://groups.google.com/forum/#!forum/rails-i18n) - The project's mailing list. * [GitHub: rails-i18n](https://github.com/svenfuchs/rails-i18n) - Code repository and issue tracker for the rails-i18n project. Most importantly you can find lots of [example translations](https://github.com/svenfuchs/rails-i18n/tree/master/rails/locale) for Rails that should work for your application in most cases. * [GitHub: i18n](https://github.com/svenfuchs/i18n) - Code repository and issue tracker for the i18n gem. @@ -1183,7 +1210,7 @@ Authors Footnotes --------- -[^1]: Or, to quote [Wikipedia](http://en.wikipedia.org/wiki/Internationalization_and_localization): _"Internationalization is the process of designing a software application so that it can be adapted to various languages and regions without engineering changes. Localization is the process of adapting software for a specific region or language by adding locale-specific components and translating text."_ +[^1]: Or, to quote [Wikipedia](https://en.wikipedia.org/wiki/Internationalization_and_localization): _"Internationalization is the process of designing a software application so that it can be adapted to various languages and regions without engineering changes. Localization is the process of adapting software for a specific region or language by adding locale-specific components and translating text."_ [^2]: Other backends might allow or require to use other formats, e.g. a GetText backend might allow to read GetText files. |