FEATURE: Translate categories and display them when inline translations enabled

Author: nattsw

app/jobs/scheduled/automatic_translation_backfill.rb

@@ -24,10 +24,10 @@ def fetch_untranslated_model_ids(model, content_column, limit, target_locale)
             SELECT m.id
             FROM #{model.table_name} m
             #{limit_to_public_clause(model)}
-            WHERE m.deleted_at IS NULL
-              AND m.#{content_column} != ''
-              AND m.user_id > 0
-              #{max_age_clause}
+            WHERE m.#{content_column} != ''
+              #{not_deleted_clause(model)}
+              #{non_bot_clause(model)}
+              #{max_age_clause(model)}
             ORDER BY m.updated_at DESC
           )
           EXCEPT
@@ -91,22 +91,29 @@ def process_batch
         topic_ids =
           fetch_untranslated_model_ids(Topic, "title", records_to_translate, target_locale)
         post_ids = fetch_untranslated_model_ids(Post, "raw", records_to_translate, target_locale)
+        category_ids =
+          fetch_untranslated_model_ids(Category, "name", records_to_translate, target_locale)
 
-        next if topic_ids.empty? && post_ids.empty?
+        next if topic_ids.empty? && post_ids.empty? && category_ids.empty?
 
         DiscourseTranslator::VerboseLogger.log(
-          "Translating #{topic_ids.size} topics and #{post_ids.size} posts to #{target_locale}",
+          "Translating #{topic_ids.size} topics, #{post_ids.size} posts, #{category_ids.size} categories, to #{target_locale}",
         )
 
         translate_records(Topic, topic_ids, target_locale)
         translate_records(Post, post_ids, target_locale)
+        translate_records(Category, category_ids, target_locale)
       end
     end
 
-    def max_age_clause
+    def max_age_clause(model)
       return "" if SiteSetting.automatic_translation_backfill_max_age_days <= 0
 
-      "AND m.created_at > NOW() - INTERVAL '#{SiteSetting.automatic_translation_backfill_max_age_days} days'"
+      if model == Post || model == Topic
+        "AND m.created_at > NOW() - INTERVAL '#{SiteSetting.automatic_translation_backfill_max_age_days} days'"
+      else
+        ""
+      end
     end
 
     def limit_to_public_clause(model)
@@ -130,5 +137,15 @@ def limit_to_public_clause(model)
 
       limit_to_public_clause
     end
+
+    def non_bot_clause(model)
+      return "AND m.user_id > 0" if model == Post || model == Topic
+      ""
+    end
+
+    def not_deleted_clause(model)
+      return "AND m.deleted_at IS NULL" if model == Post || model == Topic
+      ""
+    end
   end
 end

app/models/discourse_translator/category_locale.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+module DiscourseTranslator
+  class CategoryLocale < ActiveRecord::Base
+    self.table_name = "discourse_translator_category_locales"
+
+    belongs_to :category
+
+    validates :category_id, presence: true
+    validates :detected_locale, presence: true
+  end
+end

app/models/discourse_translator/category_translation.rb

@@ -0,0 +1,14 @@
+# frozen_string_literal: true
+
+module DiscourseTranslator
+  class CategoryTranslation < ActiveRecord::Base
+    self.table_name = "discourse_translator_category_translations"
+
+    belongs_to :category
+
+    validates :category_id, presence: true
+    validates :locale, presence: true
+    validates :translation, presence: true
+    validates :locale, uniqueness: { scope: :category_id }
+  end
+end

app/services/discourse_ai/category_translator.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+module DiscourseAi
+  class CategoryTranslator < BaseTranslator
+    PROMPT_TEMPLATE = <<~TEXT.freeze
+      You are a translation service specializing in translating forum category names to the asked target_language. Your task is to provide accurate and contextually appropriate translations while adhering to the following guidelines:
+
+      1. Translate the category name to target_language asked
+      2. Keep proper nouns and technical terms in their original language
+      3. Keep the translated category name length short, and close to the original length
+      4. Ensure the translation maintains the original meaning
+
+      Provide your translation in the following JSON format:
+
+      <output>
+      {"translation": "Your target_language translation here"}
+      </output>
+
+      Here are three examples of correct translation
+
+      Original: {"name":"Cats and Dogs", "target_language":"Chinese"}
+      Correct translation: {"translation": "猫和狗"}
+
+      Original: {"name":"General", "target_language":"French"}
+      Correct translation: {"translation": "Général"}
+
+      Original: {"name": "Q&A", "target_language": "Portuguese"}
+      Correct translation: {"translation": "Perguntas e Respostas"}
+
+      Remember to keep proper nouns like "Minecraft" and "Toyota" in their original form. Translate the category name now and provide your answer in the specified JSON format.
+    TEXT
+
+    private def prompt_template
+      PROMPT_TEMPLATE
+    end
+  end
+end

app/services/discourse_ai/topic_translator.rb

@@ -3,9 +3,9 @@
 module DiscourseAi
   class TopicTranslator < BaseTranslator
     PROMPT_TEMPLATE = <<~TEXT.freeze
-      You are a translation service specializing in translating forum post titles from English to the asked target_language. Your task is to provide accurate and contextually appropriate translations while adhering to the following guidelines:
+      You are a translation service specializing in translating forum post titles to the asked target_language. Your task is to provide accurate and contextually appropriate translations while adhering to the following guidelines:
 
-      1. Translate the given title from English to target_language asked.
+      1. Translate the given title to target_language asked.
       2. Keep proper nouns and technical terms in their original language.
       3. Attempt to keep the translated title length close to the original when possible.
       4. Ensure the translation maintains the original meaning and tone.

app/services/discourse_translator/base.rb

@@ -137,6 +137,8 @@ def self.get_untranslated(translatable, raw: false)
         raw ? translatable.raw : translatable.cooked
       when "Topic"
         translatable.title
+      when "Category"
+        translatable.name
       end
     end
   end

app/services/discourse_translator/discourse_ai.rb

@@ -42,6 +42,11 @@ def self.translate!(translatable, target_locale_sym = I18n.locale)
             .join("")
         when "Topic"
           ::DiscourseAi::TopicTranslator.new(text_for_translation(translatable), language).translate
+        when "Category"
+          ::DiscourseAi::CategoryTranslator.new(
+            text_for_translation(translatable),
+            language,
+          ).translate
         end
 
       DiscourseTranslator::TranslatedContentNormalizer.normalize(translatable, translated)

db/migrate/20250401015139_create_category_translation_table.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+class CreateCategoryTranslationTable < ActiveRecord::Migration[7.2]
+  def change
+    create_table :discourse_translator_category_locales do |t|
+      t.integer :category_id, null: false
+      t.string :detected_locale, limit: 20, null: false
+      t.timestamps
+    end
+
+    create_table :discourse_translator_category_translations do |t|
+      t.integer :category_id, null: false
+      t.string :locale, null: false
+      t.text :translation, null: false
+      t.timestamps
+    end
+
+    add_index :discourse_translator_category_translations,
+              %i[category_id locale],
+              unique: true,
+              name: "idx_category_translations_on_category_id_and_locale"
+  end
+end

lib/discourse_translator/extensions/category_extension.rb

@@ -0,0 +1,11 @@
+# frozen_string_literal: true
+
+module DiscourseTranslator
+  module Extensions
+    module CategoryExtension
+      extend ActiveSupport::Concern
+      prepended { before_update :clear_translations, if: :name_changed? }
+      include Translatable
+    end
+  end
+end

lib/discourse_translator/inline_translation.rb

@@ -15,6 +15,8 @@ def inject(plugin)
       # always return early if topic and posts are in the user's effective_locale.
       # this prevents the need to load translations.
 
+      # posts
+
       plugin.register_modifier(:basic_post_serializer_cooked) do |cooked, serializer|
         if !SiteSetting.experimental_inline_translation ||
              serializer.object.locale_matches?(InlineTranslation.effective_locale) ||
@@ -25,6 +27,14 @@ def inject(plugin)
         end
       end
 
+      plugin.add_to_serializer(:basic_post, :is_translated) do
+        SiteSetting.experimental_inline_translation &&
+          !object.locale_matches?(InlineTranslation.effective_locale) &&
+          object.translation_for(InlineTranslation.effective_locale).present?
+      end
+
+      # topics
+
       plugin.register_modifier(:topic_serializer_fancy_title) do |fancy_title, serializer|
         if !SiteSetting.experimental_inline_translation ||
              serializer.object.locale_matches?(InlineTranslation.effective_locale) ||
@@ -54,12 +64,6 @@ def inject(plugin)
         end
       end
 
-      plugin.add_to_serializer(:basic_post, :is_translated) do
-        SiteSetting.experimental_inline_translation &&
-          !object.locale_matches?(InlineTranslation.effective_locale) &&
-          object.translation_for(InlineTranslation.effective_locale).present?
-      end
-
       plugin.add_to_serializer(:topic_view, :is_translated) do
         SiteSetting.experimental_inline_translation &&
           !object.topic.locale_matches?(InlineTranslation.effective_locale) &&
@@ -72,6 +76,19 @@ def inject(plugin)
       plugin.register_topic_preloader_associations(:translations) do
         SiteSetting.translator_enabled && SiteSetting.experimental_inline_translation
       end
+
+      # categories
+
+      plugin.register_modifier(:basic_category_serializer_name) do |name, serializer|
+        # "x"
+        if !SiteSetting.experimental_inline_translation ||
+             serializer.object.locale_matches?(InlineTranslation.effective_locale) ||
+             serializer.scope&.request&.params&.[]("show") == "original"
+          name
+        else
+          serializer.object.translation_for(InlineTranslation.effective_locale).presence
+        end
+      end
     end
   end
 end