Page and Slice localizer

example.rb

Page.all.each do |page|
  Slices::PageLocalizer.new(page).localize
  page.save
end

page_localizer.rb

module Slices
  class PageLocalizer
    attr_reader :page

    def initialize(page = nil)
      @page = page
    end

    def localize
      localize_fields(page)

      page.embeded_slices do |embed_name|
        page.slices_for(embed_name).each do |slice|
          localize_fields(slice)

          slice.embedded_relations.keys.each do |relation|
            slice.send(relation).each do |r|
              localize_fields(r)
            end
          end
        end
      end
    end

    private

    def localize_fields(object)
      object.class.localized_fields.each do |field, _|
        value = object.attributes[field]
        next if value.is_a?(Hash)

        # We set the value to 'nil' so we can write the correct
        # value and let Mongoid know the field has 'changed'
        object.attributes[field] = {}
        object.write_attribute(field, value)
      end
    end
  end
end

page_localizer_spec.rb

require 'spec_helper'

describe Slices::PageLocalizer do
  let :page do
    Page.new.tap do |page|
      page.attributes['name'] = 'Name'
      page.attributes['title'] = 'Title'
      page.meta_description = 'Meta Description'
    end
  end

  let :slice do
    TitleSlice.new.tap do |slice|
      slice.attributes['title'] = 'Title'
    end
  end

  let :attachment do
    SlideshowSlice::Slide.new.tap do |slide|
      slide.attributes['caption'] = 'Caption'
    end
  end

  before do
    page.slices << slice
    page.slices << SlideshowSlice.new(slides: [attachment])
  end

  context "before migration" do
    it "has no translated values for a localized field" do
      expect(page.name_translations).to eq 'Name'
    end

    it "has no translated values for a localized field on a slice" do
      expect(slice.title_translations).to eq 'Title'
    end

    it "has no translated values for a localized attachment in a slice" do
      expect(attachment.caption_translations).to eq 'Caption'
    end
  end

  context "after localization" do
    before do
      Slices::PageLocalizer.new(page).localize
    end

    it "converts page fields to localized fields" do
      expect(page.name).to eq 'Name'
      expect(page.name_translations).to eq({ 'en' => 'Name' })
    end

    it "converts fields on slices to localized fields" do
      expect(slice.title).to eq 'Title'
      expect(slice.title_translations).to eq({ 'en' => 'Title' })
    end

    it "converts fields on slice attachments to localized fields" do
      expect(attachment.caption).to eq 'Caption'
      expect(attachment.caption_translations).to eq({ 'en' => 'Caption' })
    end

    it "marks the fields as dirty" do
      expect(page.name_changed?).to eq(true)
      expect(slice.title_changed?).to eq(true)
      expect(attachment.caption_changed?).to eq(true)
    end

    it "ignores already localized fields" do
      expect(page.meta_description).to eq 'Meta Description'
    end
  end
end