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.

Methods
H
I
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Included Modules
Instance Public 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.

Source: show | on GitHub 

# File activemodel/lib/active_model/translation.rb, line 45
def human_attribute_name(attribute, options = {})
  defaults  = []
  parts     = attribute.to_s.split(".", 2)
  attribute = parts.pop
  namespace = parts.pop

  if namespace
    lookup_ancestors.each do |klass|
      defaults << :"#{self.i18n_scope}.attributes.#{klass.model_name.i18n_key}/#{namespace}.#{attribute}"
    end
    defaults << :"#{self.i18n_scope}.attributes.#{namespace}.#{attribute}"
  else
    lookup_ancestors.each do |klass|
      defaults << :"#{self.i18n_scope}.attributes.#{klass.model_name.i18n_key}.#{attribute}"
    end
  end

  defaults << :"attributes.#{attribute}"
  defaults << options.delete(:default) if options[:default]
  defaults << attribute.humanize

  options.reverse_merge! :count => 1, :default => defaults
  I18n.translate(defaults.shift, options)
end
i18n_scope()

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

Source: show | on GitHub 

# File activemodel/lib/active_model/translation.rb, line 27
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 #human_attribute_name.

Source: show | on GitHub 

# File activemodel/lib/active_model/translation.rb, line 35
def lookup_ancestors
  self.ancestors.select { |x| x.respond_to?(:model_name) }
end