module ActiveModel::Translation

Active Model Translation¶ ↑

Provides integration between your object and the Rails internationalization (i18n) framework.

A minimal implementation could be:

class TranslatedPerson
  extend ActiveModel::Translation
end

TranslatedPerson.human_attribute_name('my_attribute')
# => "My attribute"

This also provides the required class methods for hooking into the Rails internationalization API, including being able to define a class-based i18n_scope and lookup_ancestors to find translations in parent classes.

Attributes

raise_on_missing_translations [RW]

Public Instance Methods

human_attribute_name (attribute, options = {})

Transforms attribute names into a more human format, such as “First name” instead of “first_name”.

Person.human_attribute_name("first_name") # => "First name"

Specify options with additional translating options.

# File activemodel/lib/active_model/translation.rb, line 48
def human_attribute_name(attribute, options = {})
  attribute = attribute.to_s

  if attribute.include?(".")
    namespace, _, attribute = attribute.rpartition(".")
    namespace.tr!(".", "/")

    if attribute.present?
      key = "#{namespace}.#{attribute}"
      separator = "/"
    else
      key = namespace
      separator = "."
    end

    defaults = lookup_ancestors.map do |klass|
      :"#{i18n_scope}.attributes.#{klass.model_name.i18n_key}#{separator}#{key}"
    end
    defaults << :"#{i18n_scope}.attributes.#{key}"
    defaults << :"attributes.#{key}"
  else
    defaults = lookup_ancestors.map do |klass|
      :"#{i18n_scope}.attributes.#{klass.model_name.i18n_key}.#{attribute}"
    end
  end

  raise_on_missing = options.fetch(:raise, Translation.raise_on_missing_translations)

  defaults << :"attributes.#{attribute}"
  defaults << options[:default] if options[:default]
  defaults << MISSING_TRANSLATION unless raise_on_missing

  translation = I18n.translate(defaults.shift, count: 1, raise: raise_on_missing, **options, default: defaults)
  if translation == MISSING_TRANSLATION
    translation = attribute.present? ? attribute.humanize : namespace.humanize
  end
  translation
end

i18n_scope ()

Returns the i18n_scope for the class. Override if you want custom lookup.

# File activemodel/lib/active_model/translation.rb, line 28
def i18n_scope
  :activemodel
end

lookup_ancestors ()

When localizing a string, it goes through the lookup returned by this method, which is used in ActiveModel::Name#human, ActiveModel::Errors#full_messages and ActiveModel::Translation#human_attribute_name.

# File activemodel/lib/active_model/translation.rb, line 36
def lookup_ancestors
  ancestors.select { |x| x.respond_to?(:model_name) }
end