Simplify getting I18nContent translations

This code might be slightly slower because it performs one query per
field in the form, but I didn't notice any differences on my development
machine, and the code is now much easier to understand.

app/controllers/admin/site_customization/information_texts_controller.rb

@@ -2,9 +2,8 @@ class Admin::SiteCustomization::InformationTextsController < Admin::SiteCustomiz
   before_action :delete_translations, only: [:update]
 
   def index
-    fetch_existing_keys
-    append_or_create_keys
-    @content = @content[@tab.to_s]
+    @tab = params[:tab] || :debates
+    @content = I18nContent.content_for(@tab)
   end
 
   def update
@@ -50,29 +49,6 @@ class Admin::SiteCustomization::InformationTextsController < Admin::SiteCustomiz
       end
     end
 
-    def fetch_existing_keys
-      @existing_keys = {}
-      @tab = params[:tab] || :debates
-
-      I18nContent.begins_with_key(@tab).map { |content|
-        @existing_keys[content.key] = content
-      }
-    end
-
-    def append_or_create_keys
-      @content = {}
-      I18n.backend.send(:init_translations) unless I18n.backend.initialized?
-
-      locale = params[:locale] || I18n.locale
-      translations = I18n.backend.send(:translations)[locale.to_sym]
-
-      translations.each do |key, value|
-        @content[key.to_s] = I18nContent.flat_hash(value).keys.map { |string|
-          @existing_keys["#{key.to_s}.#{string}"] || I18nContent.new(key: "#{key.to_s}.#{string}")
-        }
-      end
-    end
-
     def translation_params
       I18nContent.translated_attribute_names.product(enabled_translations).map do |attr_name, loc|
         I18nContent.localized_attr_name_for(attr_name, loc)

app/helpers/site_customization_helper.rb

@@ -8,11 +8,9 @@ module SiteCustomizationHelper
   end
 
   def translation_for_locale(content, locale)
-    i18n_content = I18nContent.where(key: content.key).first
-
-    if i18n_content.present?
+    if content.present?
       I18nContentTranslation.where(
-        i18n_content_id: i18n_content.id,
+        i18n_content_id: content.id,
         locale: locale
       ).first.try(:value)
     else

app/models/i18n_content.rb

@@ -1,7 +1,6 @@
 class I18nContent < ApplicationRecord
 
   scope :by_key,          ->(key) { where(key: key) }
-  scope :begins_with_key, ->(key) { where("key ILIKE ?", "#{key}%") }
 
   validates :key, uniqueness: true
 
@@ -46,4 +45,17 @@ class I18nContent < ApplicationRecord
     return output
   end
 
+  def self.content_for(tab)
+    flat_hash(translations_for(tab)).keys.map do |string|
+      I18nContent.find_or_initialize_by(key: string)
+    end
+  end
+
+  def self.translations_for(tab)
+    I18n.backend.send(:init_translations) unless I18n.backend.initialized?
+
+    I18n.backend.send(:translations)[I18n.locale].select do |key, _translations|
+      key.to_s == tab.to_s
+    end
+  end
 end

spec/models/i18n_content_spec.rb

@@ -27,20 +27,6 @@ RSpec.describe I18nContent, type: :model do
       expect(query.size).to eq(1)
       expect(query).to eq([debate_title])
     end
-
-    it "return all matching records when #begins_with_key is used" do
-      debate_text    = create(:i18n_content, key: "debates.form.debate_text")
-      debate_title   = create(:i18n_content, key: "debates.form.debate_title")
-      proposal_title = create(:i18n_content, key: "proposals.form.proposal_title")
-
-      expect(I18nContent.all.size).to eq(3)
-
-      query = I18nContent.begins_with_key("debates")
-
-      expect(query.size).to eq(2)
-      expect(query).to eq([debate_text, debate_title])
-      expect(query).not_to include(proposal_title)
-    end
   end
 
   context "Globalize" do