Acts as Read-Only I18n Localised

A variant on the acts_as_localized theme for when you have static seed data in your system that must be localised.

Why use it?

It's designed for a specific use-case, namely the localisation of your seed data.
It works with the standard Rails I18n system and assumes you already have a lot of your localisation data in config/locales/*.yml, or you have your i18n stuff already set up in a database.
It's fast and easy.

Example of use

In config/locales/categories.en.yml

en:
  categories:
    fruits:
      name: Great fresh fruit
      description: Our fantastic range of seasonal and local fresh fruit will delight you.
    vegetables:
      name: Farm fresh veggies
      description: Our locally grown and freshly harvested veggies are simply delicious.
    meats:
      name: Farm-fresh seasonal meat
      description: >-
        Loved in life then lightly killed, our meat is locally sourced from small farms
        that meet our demanding standards.

In app/models/category.rb

class Category < ActiveRecord::Base
  include ActsAsReadOnlyI18nLocalised
  validates :slug, format: {with: /^[a-z]+[\-?[a-z]*]*$/},
                   uniqueness: true,
                   presence: true
  has_many :products
  validates_associated :products

  acts_as_read_only_i18n_localised :name, :description
end

This simply generates appropriate name and description methods along the lines of

def name
  key = "#{self.class.name.pluralize}.#{slug}.name".downcase.to_sym
  return I18n.t(key)
end

with the effect that a call to category.name will always return the localised name using the standard I18n system.

Depending on how your code is configured, I18n will raise a MissingTranslationData exception if the key does correspond to any data. Exceptions on missing keys is usually turned on in development and test but not on staging or production. See The Rails I18n Guide for more.

Seeding your database

In db/seeds.rb add something like

require 'i18n'

I18n.t(:categories).each do |key, data|
  Category.create(slug: key)
end

Development

To build the gem

gem build acts_as_read_only_i18n_localised.gemspec

To test it

rspec

rake