Allow different locales per tenant

Note that, currently, we take these settings from the database but we
don't provide a way to edit them through the admin interface, so the
locales must be manually introduced through a Rails console.

While we did consider using a comma-separated list, we're using spaces
in order to be consistent with the way we store the allowed content
types settings.

The `enabled_locales` nomenclature, which contrasts with
`available_locales`, is probably subconsciously based on similar
patterns like the one Nginx uses to enable sites.

Note that we aren't using `Setting.enabled_locales` in the globalize
initializer when setting the fallbacks. This means the following test
(which we could add to the shared globalizable examples) would fail:

```
it "Falls back to an enabled locale if the fallback is not enabled" do
  Setting["locales.default"] = "en"
  Setting["locales.enabled"] = "fr en"
  allow(I18n.fallbacks).to receive(:[]).and_return([:fr, :es])
  Globalize.set_fallbacks_to_all_available_locales

  I18n.with_locale(:fr) do
    expect(record.send(attribute)).to eq "In English"
  end
end
```

The reason is that the code making this test pass could be:

```
def Globalize.set_fallbacks_to_all_available_locales
  Globalize.fallbacks = I18n.available_locales.index_with do |locale|
    ((I18n.fallbacks[locale] & Setting.enabled_locales) + Setting.enabled_locales).uniq
  end
end
```

However, this would make it impossible to run `rake db:migrate` on new
applications because the initializer would try to load the `Setting`
model but the `settings` table wouldn't exist at that point.

Besides, this is a really rare case that IMHO we don't need to support.
For this scenario, an installation would have to enable a locale, create
records with contents in that locale, then disable that locale and have
that locale as a fallback for a language where content for that record
wasn't created. If that happened, it would be solved by creating content
for that record in every enabled language.

.rubocop.yml

@@ -574,6 +574,7 @@ RSpec/InstanceVariable:
   Enabled: true
   Exclude:
     - spec/controllers/concerns/has_orders_spec.rb
+    - spec/form_builders/translatable_form_builder_spec.rb
 
 RSpec/LetBeforeExamples:
   Enabled: true

app/components/admin/site_customization/content_blocks/form_content_block_component.html.erb

@@ -6,7 +6,7 @@
     <%= f.select :name, options_for_select(valid_blocks, selected_content_block) %>
   </div>
   <div class="small-12 medium-6 column">
-    <%= f.select :locale, I18n.available_locales %>
+    <%= f.select :locale, Setting.enabled_locales %>
   </div>
 
   <div class="small-12 column">

app/components/admin/site_customization/content_blocks/form_heading_content_block_component.html.erb

@@ -7,7 +7,7 @@
   </div>
   <div class="small-12 medium-6 column">
     <%= label_tag :locale %>
-    <%= select_tag :locale, options_for_select(I18n.available_locales, content_block.locale.to_sym) %>
+    <%= select_tag :locale, options_for_select(Setting.enabled_locales, content_block.locale.to_sym) %>
   </div>
   <div class="small-12 column">
     <%= label_tag :body %>

app/components/admin/site_customization/information_texts/form_component.html.erb

@@ -1,13 +1,13 @@
 <%= render Shared::GlobalizeLocalesComponent.new %>
 
 <%= form_tag admin_site_customization_information_texts_path do %>
-  <% I18n.available_locales.each do |l| %>
+  <% enabled_locales.each do |l| %>
     <%= translation_enabled_tag l, site_customization_enable_translation?(l) %>
   <% end %>
   <% contents.each do |group| %>
     <% group.each do |content| %>
       <b><%= content.key %></b>
-      <% content.globalize_locales.each do |locale| %>
+      <% (content.globalize_locales & enabled_locales.map(&:to_sym)).each do |locale| %>
         <%= render Admin::SiteCustomization::InformationTexts::FormFieldComponent.new(content, locale: locale) %>
       <% end %>
     <% end %>

app/components/admin/site_customization/information_texts/form_component.rb

@@ -11,4 +11,8 @@ class Admin::SiteCustomization::InformationTexts::FormComponent < ApplicationCom
     def translation_enabled_tag(locale, enabled)
       hidden_field_tag("enabled_translations[#{locale}]", (enabled ? 1 : 0))
     end
+
+    def enabled_locales
+      Setting.enabled_locales
+    end
 end

app/components/layout/locale_switcher_component.rb

@@ -12,7 +12,7 @@ class Layout::LocaleSwitcherComponent < ApplicationComponent
     end
 
     def locales
-      I18n.available_locales
+      Setting.enabled_locales
     end
 
     def label

app/components/shared/globalize_locales_component.html.erb

@@ -13,7 +13,7 @@
     <%= select_language_error %>
     <div class="margin-bottom">
       <% if manage_languages %>
-        <% I18n.available_locales.each do |locale| %>
+        <% Setting.enabled_locales.each do |locale| %>
           <%= link_to t("shared.translations.remove_language"), "#",
                       style: display_destroy_locale_style(locale),
                       class: "delete js-delete-language js-delete-#{locale}",

app/components/shared/globalize_locales_component.rb

@@ -15,7 +15,7 @@ class Shared::GlobalizeLocalesComponent < ApplicationComponent
     end
 
     def available_locales
-      I18n.available_locales.select { |locale| enabled_locale?(resource, locale) }.map do |locale|
+      Setting.enabled_locales.select { |locale| enabled_locale?(resource, locale) }.map do |locale|
         [name_for_locale(locale), locale, { data: { locale: locale }}]
       end
     end
@@ -84,7 +84,7 @@ class Shared::GlobalizeLocalesComponent < ApplicationComponent
     end
 
     def all_language_options
-      I18n.available_locales.map do |locale|
+      Setting.enabled_locales.map do |locale|
         [name_for_locale(locale), locale]
       end
     end

app/controllers/application_controller.rb

@@ -51,9 +51,9 @@ class ApplicationController < ActionController::Base
     end
 
     def current_locale
-      if I18n.available_locales.include?(params[:locale]&.to_sym)
+      if Setting.enabled_locales.include?(params[:locale]&.to_sym)
         params[:locale]
-      elsif I18n.available_locales.include?(session[:locale]&.to_sym)
+      elsif Setting.enabled_locales.include?(session[:locale]&.to_sym)
         session[:locale]
       else
         I18n.default_locale

app/controllers/management/base_controller.rb

@@ -40,7 +40,7 @@ class Management::BaseController < ActionController::Base
     end
 
     def switch_locale(&action)
-      if params[:locale] && I18n.available_locales.include?(params[:locale].to_sym)
+      if params[:locale] && Setting.enabled_locales.include?(params[:locale].to_sym)
         session[:locale] = params[:locale].to_s
       end
 

app/controllers/subscriptions_controller.rb

@@ -38,6 +38,6 @@ class SubscriptionsController < ApplicationController
     end
 
     def find_locale
-      I18n.available_locales.find { |locale| locale == @user.locale&.to_sym } || I18n.locale
+      Setting.enabled_locales.find { |locale| locale == @user.locale&.to_sym } || I18n.locale
     end
 end

app/form_builders/translatable_form_builder.rb

@@ -63,7 +63,7 @@ class TranslatableFormBuilder < ConsulFormBuilder
 
     def visible_locales
       if @template.translations_interface_enabled?
-        @object.globalize_locales
+        Setting.enabled_locales & @object.globalize_locales
       else
         [I18n.locale]
       end

app/models/budget/content_block.rb

@@ -1,6 +1,6 @@
 class Budget
   class ContentBlock < ApplicationRecord
-    validates :locale, presence: true, inclusion: { in: I18n.available_locales.map(&:to_s) }
+    validates :locale, presence: true, inclusion: { in: ->(*) { Setting.enabled_locales.map(&:to_s) }}
     validates :heading, presence: true, uniqueness: { scope: :locale }
 
     belongs_to :heading

app/models/i18n_content.rb

@@ -119,7 +119,7 @@ class I18nContent < ApplicationRecord
     end
   end
 
-  def self.update(contents, enabled_translations = I18n.available_locales)
+  def self.update(contents, enabled_translations = Setting.enabled_locales)
     contents.each do |content|
       values = content[:values].slice(*translation_params(enabled_translations))
 

app/models/setting.rb

@@ -95,6 +95,7 @@ class Setting < ApplicationRecord
         "html.per_page_code_body": "",
         # Code to be included at the top (inside <head>) of every page (useful for tracking)
         "html.per_page_code_head": "",
+        "locales.enabled": nil,
         "map.latitude": 51.48,
         "map.longitude": 0.0,
         "map.zoom": 10,
@@ -219,5 +220,11 @@ class Setting < ApplicationRecord
     def archived_proposals_date_limit
       Setting["months_to_archive_proposals"].to_i.months.ago
     end
+
+    def enabled_locales
+      locales = Setting["locales.enabled"].to_s.split.map(&:to_sym)
+
+      (locales & I18n.available_locales).presence || I18n.available_locales
+    end
   end
 end

app/models/site_customization/content_block.rb

@@ -1,7 +1,7 @@
 class SiteCustomization::ContentBlock < ApplicationRecord
   VALID_BLOCKS = %w[top_links footer footer_legal subnavigation_left subnavigation_right].freeze
 
-  validates :locale, presence: true, inclusion: { in: I18n.available_locales.map(&:to_s) }
+  validates :locale, presence: true, inclusion: { in: ->(*) { Setting.enabled_locales.map(&:to_s) }}
   validates :name, presence: true, uniqueness: { scope: :locale }, inclusion: { in: ->(*) { VALID_BLOCKS }}
 
   def self.block_for(name, locale)

db/dev_seeds.rb

@@ -23,7 +23,11 @@ def log(msg)
 end
 
 def random_locales
-  [I18n.default_locale, *(I18n.available_locales & %i[en es]), *I18n.available_locales.sample(4)].uniq.take(5)
+  [
+    I18n.default_locale,
+    *(Setting.enabled_locales & %i[en es]),
+    *Setting.enabled_locales.sample(4)
+  ].uniq.take(5)
 end
 
 def random_locales_attributes(**attribute_names_with_values)

db/dev_seeds/banners.rb

@@ -9,7 +9,7 @@ section "Creating banners" do
                         post_started_at: rand((1.week.ago)..(1.day.ago)),
                         post_ended_at: rand((1.day.ago)..(1.week.from_now)),
                         created_at: rand((1.week.ago)..Time.current))
-    I18n.available_locales.map do |locale|
+    Setting.enabled_locales.map do |locale|
       Globalize.with_locale(locale) do
         banner.description = "Description for locale #{locale}"
         banner.title = "Title for locale #{locale}"

db/dev_seeds/polls.rb

@@ -41,7 +41,7 @@ section "Creating polls" do
 
   Poll.find_each do |poll|
     name = poll.name
-    I18n.available_locales.map do |locale|
+    Setting.enabled_locales.map do |locale|
       Globalize.with_locale(locale) do
         poll.name = "#{name} (#{locale})"
         poll.summary = "Summary for locale #{locale}"
@@ -59,7 +59,7 @@ section "Creating Poll Questions & Answers" do
       question = Poll::Question.new(author: User.sample,
                                     title: question_title,
                                     poll: poll)
-      I18n.available_locales.map do |locale|
+      Setting.enabled_locales.map do |locale|
         Globalize.with_locale(locale) do
           question.title = "#{question_title} (#{locale})"
         end
@@ -71,7 +71,7 @@ section "Creating Poll Questions & Answers" do
                                             title: title.capitalize,
                                             description: description,
                                             given_order: index + 1)
-        I18n.available_locales.map do |locale|
+        Setting.enabled_locales.map do |locale|
           Globalize.with_locale(locale) do
             answer.title = "#{title} (#{locale})"
             answer.description = "#{description} (#{locale})"
@@ -235,7 +235,7 @@ section "Creating Poll Questions from Proposals" do
     question = Poll::Question.new(poll: poll)
     question.copy_attributes_from_proposal(proposal)
     question_title = question.title
-    I18n.available_locales.map do |locale|
+    Setting.enabled_locales.map do |locale|
       Globalize.with_locale(locale) do
         question.title = "#{question_title} (#{locale})"
       end
@@ -247,7 +247,7 @@ section "Creating Poll Questions from Proposals" do
                                           title: title.capitalize,
                                           description: description,
                                           given_order: index + 1)
-      I18n.available_locales.map do |locale|
+      Setting.enabled_locales.map do |locale|
         Globalize.with_locale(locale) do
           answer.title = "#{title} (#{locale})"
           answer.description = "#{description} (#{locale})"
@@ -265,7 +265,7 @@ section "Creating Successful Proposals" do
     question = Poll::Question.new(poll: poll)
     question.copy_attributes_from_proposal(proposal)
     question_title = question.title
-    I18n.available_locales.map do |locale|
+    Setting.enabled_locales.map do |locale|
       Globalize.with_locale(locale) do
         question.title = "#{question_title} (#{locale})"
       end
@@ -277,7 +277,7 @@ section "Creating Successful Proposals" do
                                           title: title.capitalize,
                                           description: description,
                                           given_order: index + 1)
-      I18n.available_locales.map do |locale|
+      Setting.enabled_locales.map do |locale|
         Globalize.with_locale(locale) do
           answer.title = "#{title} (#{locale})"
           answer.description = "#{description} (#{locale})"

db/pages/accessibility.rb

@@ -104,7 +104,7 @@ end
 
 if SiteCustomization::Page.find_by(slug: "accessibility").nil?
   page = SiteCustomization::Page.new(slug: "accessibility", status: "published")
-  I18n.available_locales.each do |locale|
+  Setting.enabled_locales.each do |locale|
     I18n.with_locale(locale) { generate_content(page) }
   end
 end

db/pages/census_terms.rb

@@ -7,7 +7,7 @@ end
 if SiteCustomization::Page.find_by(slug: "census_terms").nil?
   page = SiteCustomization::Page.new(slug: "census_terms", status: "published")
   page.print_content_flag = true
-  I18n.available_locales.each do |locale|
+  Setting.enabled_locales.each do |locale|
     I18n.with_locale(locale) { generate_content(page) }
   end
 end

db/pages/conditions.rb

@@ -8,7 +8,7 @@ end
 if SiteCustomization::Page.find_by(slug: "conditions").nil?
   page = SiteCustomization::Page.new(slug: "conditions", status: "published")
   page.print_content_flag = true
-  I18n.available_locales.each do |locale|
+  Setting.enabled_locales.each do |locale|
     I18n.with_locale(locale) { generate_content(page) }
   end
 end

db/pages/faq.rb

@@ -5,7 +5,7 @@ def generate_content(page)
 end
 if SiteCustomization::Page.find_by(slug: "faq").nil?
   page = SiteCustomization::Page.new(slug: "faq", status: "published")
-  I18n.available_locales.each do |locale|
+  Setting.enabled_locales.each do |locale|
     I18n.with_locale(locale) { generate_content(page) }
   end
 end

db/pages/privacy.rb

@@ -7,7 +7,7 @@ end
 if SiteCustomization::Page.find_by(slug: "privacy").nil?
   page = SiteCustomization::Page.new(slug: "privacy", status: "published")
   page.print_content_flag = true
-  I18n.available_locales.each do |locale|
+  Setting.enabled_locales.each do |locale|
     I18n.with_locale(locale) { generate_content(page) }
   end
 end

db/pages/welcome_level_three_verified.rb

@@ -17,7 +17,7 @@ end
 
 if SiteCustomization::Page.find_by(slug: "welcome_level_three_verified").nil?
   page = SiteCustomization::Page.new(slug: "welcome_level_three_verified", status: "published")
-  I18n.available_locales.each do |locale|
+  Setting.enabled_locales.each do |locale|
     I18n.with_locale(locale) { generate_content(page) }
   end
 end

db/pages/welcome_level_two_verified.rb

@@ -22,7 +22,7 @@ def generate_content(page)
 end
 if SiteCustomization::Page.find_by(slug: "welcome_level_two_verified").nil?
   page = SiteCustomization::Page.new(slug: "welcome_level_two_verified", status: "published")
-  I18n.available_locales.each do |locale|
+  Setting.enabled_locales.each do |locale|
     I18n.with_locale(locale) { generate_content(page) }
   end
 end

db/pages/welcome_not_verified.rb

@@ -22,7 +22,7 @@ def generate_content(page)
 end
 if SiteCustomization::Page.find_by(slug: "welcome_not_verified").nil?
   page = SiteCustomization::Page.new(slug: "welcome_not_verified", status: "published")
-  I18n.available_locales.each do |locale|
+  Setting.enabled_locales.each do |locale|
     I18n.with_locale(locale) { generate_content(page) }
   end
 end

spec/components/admin/site_customization/content_blocks/form_content_block_component_spec.rb

@@ -0,0 +1,18 @@
+require "rails_helper"
+
+describe Admin::SiteCustomization::ContentBlocks::FormContentBlockComponent do
+  describe "locale selector" do
+    let(:content_block) { create(:site_customization_content_block, locale: "de") }
+    let(:component) do
+      Admin::SiteCustomization::ContentBlocks::FormContentBlockComponent.new(content_block)
+    end
+
+    it "only includes enabled settings" do
+      Setting["locales.enabled"] = "de fr"
+
+      render_inline component
+
+      expect(page).to have_select "locale", options: ["de", "fr"]
+    end
+  end
+end

spec/components/admin/site_customization/content_blocks/form_heading_content_block_component_spec.rb

@@ -0,0 +1,18 @@
+require "rails_helper"
+
+describe Admin::SiteCustomization::ContentBlocks::FormHeadingContentBlockComponent do
+  describe "locale selector" do
+    let(:content_block) { create(:heading_content_block, locale: "de") }
+    let(:component) do
+      Admin::SiteCustomization::ContentBlocks::FormHeadingContentBlockComponent.new(content_block)
+    end
+
+    it "only includes enabled settings" do
+      Setting["locales.enabled"] = "de fr"
+
+      render_inline component
+
+      expect(page).to have_select "locale", options: ["de", "fr"]
+    end
+  end
+end

spec/components/admin/site_customization/information_texts/form_component_spec.rb

@@ -0,0 +1,29 @@
+require "rails_helper"
+
+describe Admin::SiteCustomization::InformationTexts::FormComponent do
+  describe "enabled_translations fields" do
+    it "renders fields for enabled locales" do
+      Setting["locales.enabled"] = "en es"
+      content = create(:i18n_content)
+
+      render_inline Admin::SiteCustomization::InformationTexts::FormComponent.new([[content]])
+
+      expect(page).to have_css "input[name^='enabled_translations']", count: 2, visible: :all
+      expect(page).to have_css "input[name='enabled_translations[en]']", visible: :hidden
+      expect(page).to have_css "input[name='enabled_translations[es]']", visible: :hidden
+    end
+  end
+
+  describe "text fields" do
+    it "renders fields for enabled locales" do
+      Setting["locales.enabled"] = "en es"
+      content = create(:i18n_content, key: "system.failure")
+
+      render_inline Admin::SiteCustomization::InformationTexts::FormComponent.new([[content]])
+
+      expect(page).to have_css "textarea[name^='contents[content_system.failure]']", count: 2, visible: :all
+      expect(page).to have_field "contents[content_system.failure]values[value_en]"
+      expect(page).to have_field "contents[content_system.failure]values[value_es]"
+    end
+  end
+end

spec/components/layout/locale_switcher_component_spec.rb

@@ -97,4 +97,20 @@ describe Layout::LocaleSwitcherComponent do
       expect(page).to have_css "[href='/?locale=en'][data-turbolinks=true]"
     end
   end
+
+  context "when not all available locales are enabled" do
+    before do
+      allow(I18n).to receive(:available_locales).and_return(%i[en es fr])
+      Setting["locales.enabled"] = "es fr"
+    end
+
+    it "displays the enabled locales" do
+      render_inline component
+
+      expect(page).to have_link count: 2
+      expect(page).to have_link "Español"
+      expect(page).to have_link "Français"
+      expect(page).not_to have_link "English"
+    end
+  end
 end

spec/components/shared/globalize_locales_component_spec.rb

@@ -0,0 +1,49 @@
+require "rails_helper"
+
+describe Shared::GlobalizeLocalesComponent do
+  describe "Language selector" do
+    it "only includes enabled locales" do
+      Setting["locales.enabled"] = "en nl"
+
+      I18n.with_locale(:en) do
+        render_inline Shared::GlobalizeLocalesComponent.new
+
+        expect(page).to have_select options: ["Choose language", "English"]
+      end
+
+      I18n.with_locale(:es) do
+        render_inline Shared::GlobalizeLocalesComponent.new
+
+        expect(page).to have_select options: ["Seleccionar idioma"]
+      end
+    end
+  end
+
+  describe "links to destroy languages" do
+    it "only includes enabled locales" do
+      Setting["locales.enabled"] = "en nl"
+
+      I18n.with_locale(:en) do
+        render_inline Shared::GlobalizeLocalesComponent.new
+
+        expect(page).to have_css "a[data-locale]", count: 1
+      end
+
+      I18n.with_locale(:es) do
+        render_inline Shared::GlobalizeLocalesComponent.new
+
+        expect(page).not_to have_css "a[data-locale]"
+      end
+    end
+  end
+
+  describe "Add language selector" do
+    it "only includes enabled locales" do
+      Setting["locales.enabled"] = "en nl"
+
+      render_inline Shared::GlobalizeLocalesComponent.new
+
+      expect(page).to have_select options: ["Add language", "English", "Nederlands"]
+    end
+  end
+end

spec/controllers/application_controller_spec.rb

@@ -54,6 +54,22 @@ describe ApplicationController do
       expect(response.body).to eq "es"
     end
 
+    it "only accepts enabled locales" do
+      Setting["locales.enabled"] = "en es fr"
+
+      get :index, params: { locale: :es }
+
+      expect(response.body).to eq "es"
+
+      get :index, params: { locale: :de }
+
+      expect(response.body).to eq "es"
+
+      get :index, params: { locale: :fr }
+
+      expect(response.body).to eq "fr"
+    end
+
     context "authenticated user" do
       let(:user) { create(:user) }
       before { sign_in(user) }

spec/controllers/management/base_controller_spec.rb

@@ -64,5 +64,21 @@ describe Management::BaseController do
 
       expect(response.body).to eq "es"
     end
+
+    it "only accepts enabled locales" do
+      Setting["locales.enabled"] = "en es fr"
+
+      get :index, params: { locale: :es }
+
+      expect(response.body).to eq "es"
+
+      get :index, params: { locale: :de }
+
+      expect(response.body).to eq "es"
+
+      get :index, params: { locale: :fr }
+
+      expect(response.body).to eq "fr"
+    end
   end
 end

spec/controllers/subscriptions_controller_spec.rb

@@ -28,8 +28,10 @@ describe SubscriptionsController do
       expect(session[:locale]).to eq "es"
     end
 
-    it "only accepts available locales" do
+    it "only accepts enabled locales" do
-      create(:user, locale: "wl", subscriptions_token: "mytoken")
+      Setting["locales.enabled"] = "en nl"
+
+      create(:user, locale: "es", subscriptions_token: "mytoken")
 
       get :edit, params: { token: "mytoken" }
 

spec/form_builders/translatable_form_builder_spec.rb

@@ -0,0 +1,46 @@
+require "rails_helper"
+
+describe TranslatableFormBuilder do
+  before do
+    dummy_banner = Class.new(ApplicationRecord) do
+      def self.name
+        "DummyBanner"
+      end
+      self.table_name = "banners"
+
+      translates :title, touch: true
+      include Globalizable
+      has_many :translations, class_name: "DummyBanner::Translation", foreign_key: "banner_id"
+    end
+
+    stub_const("DummyBanner", dummy_banner)
+  end
+
+  let(:builder) do
+    TranslatableFormBuilder.new(:dummy, DummyBanner.new, ApplicationController.new.view_context, {})
+  end
+
+  describe "#translatable_fields" do
+    it "renders fields for the enabled locales when the translation interface is enabled" do
+      Setting["feature.translation_interface"] = true
+      Setting["locales.enabled"] = "en fr"
+
+      builder.translatable_fields do |translations_builder|
+        render translations_builder.text_field :title
+      end
+
+      expect(page).to have_field "Title", count: 2
+    end
+  end
+
+  attr_reader :content
+
+  def render(content)
+    @content ||= ""
+    @content << content
+  end
+
+  def page
+    Capybara::Node::Simple.new(content)
+  end
+end

spec/models/budget/content_block_spec.rb

@@ -20,6 +20,14 @@ describe Budget::ContentBlock do
     expect(valid_block).to be_valid
   end
 
+  it "is not valid with a disabled locale" do
+    Setting["locales.enabled"] = "nl pt-BR"
+
+    block.locale = "en"
+
+    expect(block).not_to be_valid
+  end
+
   describe "#name" do
     it "uses the heading name" do
       block = Budget::ContentBlock.new(heading: Budget::Heading.new(name: "Central"))

spec/models/i18n_content_spec.rb

@@ -160,6 +160,16 @@ RSpec.describe I18nContent do
     end
 
     it "does not store new keys for disabled translations" do
+      Setting["locales.enabled"] = "es"
+
+      I18nContent.update([{ id: "shared.yes", values: { "value_en" => "Oh, yeah" }}])
+
+      expect(I18nContent.all).to be_empty
+    end
+
+    it "uses different enabled translations when given a parameter" do
+      Setting["locales.enabled"] = "en es"
+
       I18nContent.update([{ id: "shared.yes", values: { "value_en" => "Oh, yeah" }}], [:es])
 
       expect(I18nContent.all).to be_empty

spec/models/setting_spec.rb

@@ -258,4 +258,50 @@ describe Setting do
       expect(Setting.force_presence_postal_code?).to be true
     end
   end
+
+  describe ".available_locales" do
+    before { allow(I18n).to receive(:available_locales).and_return(%i[de en es pt-BR]) }
+
+    it "uses I18n available locales by default" do
+      Setting["locales.enabled"] = ""
+
+      expect(Setting.enabled_locales).to eq %i[de en es pt-BR]
+    end
+
+    it "defines available locales with a space-separated list" do
+      Setting["locales.enabled"] = "de es"
+
+      expect(Setting.enabled_locales).to eq %i[de es]
+    end
+
+    it "handles locales which include a dash" do
+      Setting["locales.enabled"] = "de en pt-BR"
+
+      expect(Setting.enabled_locales).to eq %i[de en pt-BR]
+    end
+
+    it "ignores extra whitespace between locales" do
+      Setting["locales.enabled"] = " de  en   pt-BR "
+
+      expect(Setting.enabled_locales).to eq %i[de en pt-BR]
+    end
+
+    it "ignores locales which aren't available" do
+      Setting["locales.enabled"] = "de es en-US fr zh-CN"
+
+      expect(Setting.enabled_locales).to eq %i[de es]
+    end
+
+    it "ignores words that don't make sense in this context" do
+      Setting["locales.enabled"] = "yes es 1234 en SuperCool"
+
+      expect(Setting.enabled_locales).to eq %i[es en]
+    end
+
+    it "uses I18n available locales when no locale is available" do
+      Setting["locales.enabled"] = "nl fr zh-CN"
+
+      expect(Setting.enabled_locales).to eq %i[de en es pt-BR]
+    end
+  end
 end

spec/models/site_customization/content_block_spec.rb

@@ -27,4 +27,12 @@ RSpec.describe SiteCustomization::ContentBlock do
     block.name = "top_links"
     expect(block).not_to be_valid
   end
+
+  it "is not valid with a disabled locale" do
+    Setting["locales.enabled"] = "nl pt-BR"
+
+    block.locale = "en"
+
+    expect(block).not_to be_valid
+  end
 end