# Authors:: Matt Aimonetti (http://railsontherun.com/),
# Sven Fuchs (http://www.artweb-design.de),
# Joshua Harvey (http://www.workingwithrails.com/person/759-joshua-harvey),
# Saimon Moore (http://saimonmoore.net),
# Stephan Soller (http://www.arkanis-development.de/)
# Copyright:: Copyright (c) 2008 The Ruby i18n Team
# License:: MIT
require 'i18n/backend/simple'
require 'i18n/exceptions'
module I18n
@@backend = nil
@@default_locale = 'en-US'
@@exception_handler = :default_exception_handler
class << self
# Returns the current backend. Defaults to +Backend::Simple+.
def backend
@@backend ||= Backend::Simple.new
end
# Sets the current backend. Used to set a custom backend.
def backend=(backend)
@@backend = backend
end
# Returns the current default locale. Defaults to 'en-US'
def default_locale
@@default_locale
end
# Sets the current default locale. Used to set a custom default locale.
def default_locale=(locale)
@@default_locale = locale
end
# Returns the current locale. Defaults to I18n.default_locale.
def locale
Thread.current[:locale] ||= default_locale
end
# Sets the current locale pseudo-globally, i.e. in the Thread.current hash.
def locale=(locale)
Thread.current[:locale] = locale
end
# Sets the exception handler.
def exception_handler=(exception_handler)
@@exception_handler = exception_handler
end
# Allows client libraries to pass arguments that specify a source for
# translation data to be loaded by the backend. The backend defines
# acceptable sources.
# E.g. the provided SimpleBackend accepts a list of paths to translation
# files which are either named *.rb and contain plain Ruby Hashes or are
# named *.yml and contain YAML data.)
def load_translations(*args)
backend.load_translations(*args)
end
# Translates, pluralizes and interpolates a given key using a given locale,
# scope, and default, as well as interpolation values.
#
# *LOOKUP*
#
# Translation data is organized as a nested hash using the upper-level keys
# as namespaces. <em>E.g.</em>, ActionView ships with the translation:
# <tt>:date => {:formats => {:short => "%b %d"}}</tt>.
#
# Translations can be looked up at any level of this hash using the key argument
# and the scope option. <em>E.g.</em>, in this example <tt>I18n.t :date</tt>
# returns the whole translations hash <tt>{:formats => {:short => "%b %d"}}</tt>.
#
# Key can be either a single key or a dot-separated key (both Strings and Symbols
# work). <em>E.g.</em>, the short format can be looked up using both:
# I18n.t 'date.formats.short'
# I18n.t :'date.formats.short'
#
# Scope can be either a single key, a dot-separated key or an array of keys
# or dot-separated keys. Keys and scopes can be combined freely. So these
# examples will all look up the same short date format:
# I18n.t 'date.formats.short'
# I18n.t 'formats.short', :scope => 'date'
# I18n.t 'short', :scope => 'date.formats'
# I18n.t 'short', :scope => %w(date formats)
#
# *INTERPOLATION*
#
# Translations can contain interpolation variables which will be replaced by
# values passed to #translate as part of the options hash, with the keys matching
# the interpolation variable names.
#
# <em>E.g.</em>, with a translation <tt>:foo => "foo {{bar}}"</tt> the option
# value for the key +bar+ will be interpolated into the translation:
# I18n.t :foo, :bar => 'baz' # => 'foo baz'
#
# *PLURALIZATION*
#
# Translation data can contain pluralized translations. Pluralized translations
# are arrays of singluar/plural versions of translations like <tt>['Foo', 'Foos']</tt>.
#
# Note that <tt>I18n::Backend::Simple</tt> only supports an algorithm for English
# pluralization rules. Other algorithms can be supported by custom backends.
#
# This returns the singular version of a pluralized translation:
# I18n.t :foo, :count => 1 # => 'Foo'
#
# These both return the plural version of a pluralized translation:
# I18n.t :foo, :count => 0 # => 'Foos'
# I18n.t :foo, :count => 2 # => 'Foos'
#
# The <tt>:count</tt> option can be used both for pluralization and interpolation.
# <em>E.g.</em>, with the translation
# <tt>:foo => ['{{count}} foo', '{{count}} foos']</tt>, count will
# be interpolated to the pluralized translation:
# I18n.t :foo, :count => 1 # => '1 foo'
#
# *DEFAULTS*
#
# This returns the translation for <tt>:foo</tt> or <tt>default</tt> if no translation was found:
# I18n.t :foo, :default => 'default'
#
# This returns the translation for <tt>:foo</tt> or the translation for <tt>:bar</tt> if no
# translation for <tt>:foo</tt> was found:
# I18n.t :foo, :default => :bar
#
# Returns the translation for <tt>:foo</tt> or the translation for <tt>:bar</tt>
# or <tt>default</tt> if no translations for <tt>:foo</tt> and <tt>:bar</tt> were found.
# I18n.t :foo, :default => [:bar, 'default']
#
# <b>BULK LOOKUP</b>
#
# This returns an array with the translations for <tt>:foo</tt> and <tt>:bar</tt>.
# I18n.t [:foo, :bar]
#
# Can be used with dot-separated nested keys:
# I18n.t [:'baz.foo', :'baz.bar']
#
# Which is the same as using a scope option:
# I18n.t [:foo, :bar], :scope => :baz
def translate(key, options = {})
locale = options.delete(:locale) || I18n.locale
backend.translate locale, key, options
rescue I18n::ArgumentError => e
raise e if options[:raise]
send @@exception_handler, e, locale, key, options
end
alias :t :translate
# Localizes certain objects, such as dates and numbers to local formatting.
def localize(object, options = {})
locale = options[:locale] || I18n.locale
format = options[:format] || :default
backend.localize(locale, object, format)
end
alias :l :localize
protected
# Handles exceptions raised in the backend. All exceptions except for
# MissingTranslationData exceptions are re-raised. When a MissingTranslationData
# was caught and the option :raise is not set the handler returns an error
# message string containing the key/scope.
def default_exception_handler(exception, locale, key, options)
return exception.message if MissingTranslationData === exception
raise exception
end
# Merges the given locale, key and scope into a single array of keys.
# Splits keys that contain dots into multiple keys. Makes sure all
# keys are Symbols.
def normalize_translation_keys(locale, key, scope)
keys = [locale] + Array(scope) + [key]
keys = keys.map{|k| k.to_s.split(/\./) }
keys.flatten.map{|k| k.to_sym}
end
end
end
