Add deduplication of routes generated by honoring the I18n.fallbacks

lib/route_translator.rb

@@ -13,10 +13,12 @@ module RouteTranslator
 
   DEFAULT_CONFIGURATION = {
     available_locales:                   [],
+    fallback_locales:                    [],
     disable_fallback:                    false,
     force_locale:                        false,
     generate_unlocalized_routes:         false,
     generate_unnamed_unlocalized_routes: false,
+    deduplicate_routes:                  false,
     hide_locale:                         false,
     host_locales:                        {},
     locale_param_key:                    :locale,
@@ -68,6 +70,16 @@ def available_locales
     end
   end
 
+  def fallback_locales
+    locales = config.fallback_locales
+
+    if locales.empty?
+      I18n.fallbacks.values.map(&:last).uniq
+    else
+      locales.map(&:to_sym)
+    end
+  end
+
   def locale_param_key
     config.locale_param_key
   end

lib/route_translator/extensions/route_set.rb

@@ -8,7 +8,7 @@ class RouteSet
       def add_localized_route(mapping, name, anchor, scope, path, controller, default_action, to, via, formatted, options_constraints, options)
         route = RouteTranslator::Route.new(self, path, name, options_constraints, options, mapping)
 
-        RouteTranslator::Translator.translations_for(route) do |locale, translated_name, translated_path, translated_options_constraints, translated_options|
+        translations_for(route) do |locale, translated_name, translated_path, translated_options_constraints, translated_options|
           translated_path_ast = ::ActionDispatch::Journey::Parser.parse(translated_path)
           translated_mapping  = translate_mapping(locale, self, translated_options, translated_path_ast, scope, controller, default_action, to, formatted, via, translated_options_constraints, anchor)
 
@@ -24,6 +24,14 @@ def add_localized_route(mapping, name, anchor, scope, path, controller, default_
 
       private
 
+      def translations_for(route, &block)
+        if RouteTranslator.config.deduplicate_routes
+          RouteTranslator::Translator.deduplicated_translations_for(route, &block)
+        else
+          RouteTranslator::Translator.translations_for(route, &block)
+        end
+      end
+
       def translate_mapping(locale, route_set, translated_options, translated_path_ast, scope, controller, default_action, to, formatted, via, translated_options_constraints, anchor)
         scope_params = {
           blocks:      (scope[:blocks] || []).dup,

lib/route_translator/translator.rb

@@ -49,12 +49,23 @@ def translate_path(path, locale, scope)
       rescue I18n::MissingTranslationData => e
         raise e unless RouteTranslator.config.disable_fallback
       end
+
+      def allowed_to_deduplicate(locale, translated_path, generated_routes)
+        return false unless RouteTranslator.config.deduplicate_routes
+        return false if I18n.default_locale == locale
+        return false if generated_routes[translated_path].nil? || generated_routes[translated_path].empty?
+        return true if generated_routes[translated_path] && !generated_routes[translated_path].empty?
+        return false if RouteTranslator.fallback_locales.include?(locale)
+
+        true
+      end
     end
 
     module_function
 
     def available_locales
       locales = RouteTranslator.available_locales
+
       # Make sure the default locale is translated in last place to avoid
       # problems with wildcards when default locale is omitted in paths. The
       # default routes will catch all paths like wildcard if it is translated first.
@@ -65,16 +76,54 @@ def available_locales
     def translations_for(route)
       RouteTranslator::Translator::RouteHelpers.add route.name, route.route_set.named_routes
 
+      generated_routes = {}
+
       available_locales.each do |locale|
         translated_path = translate_path(route.path, locale, route.scope)
         next unless translated_path
+        next if allowed_to_deduplicate(locale, translated_path, generated_routes)
+
+        translated_name                = translate_name(route.name, locale, route.route_set.named_routes.names)
+        translated_options_constraints = translate_options_constraints(route.options_constraints, locale)
+        translated_options             = translate_options(route.options, locale)
+        generated_routes[translated_path] = true
+
+        yield locale, translated_name, translated_path, translated_options_constraints, translated_options
+      end
+
+      generated_routes = nil
+    end
+
+    def deduplicated_translations_for(route)
+      RouteTranslator::Translator::RouteHelpers.add route.name, route.route_set.named_routes
+
+      generated_routes = {}
+      sorted_available_locales_for_deduplication = [I18n.default_locale] + (RouteTranslator.fallback_locales - [I18n.default_locale]) + (available_locales - RouteTranslator.fallback_locales)
+
+      sorted_available_locales_for_deduplication.each do |locale|
+        translated_path = translate_path(route.path, locale, route.scope)
+        next unless translated_path
+        next if allowed_to_deduplicate(locale, translated_path, generated_routes)
+
+        generated_routes[translated_path] ||= []
+        generated_routes[translated_path] << locale
+      end
+
+      sorted_available_locales_for_routing_pass = (available_locales - RouteTranslator.fallback_locales) + (RouteTranslator.fallback_locales - [I18n.default_locale]) + [I18n.default_locale]
+
+      sorted_available_locales_for_routing_pass.each do |locale|
+        translated_path = translate_path(route.path, locale, route.scope)
+        next unless translated_path
+        next unless generated_routes[translated_path].include?(locale)
 
         translated_name                = translate_name(route.name, locale, route.route_set.named_routes.names)
         translated_options_constraints = translate_options_constraints(route.options_constraints, locale)
         translated_options             = translate_options(route.options, locale)
 
         yield locale, translated_name, translated_path, translated_options_constraints, translated_options
       end
+
+      generated_routes = nil
     end
 
     def route_name_for(args, old_name, suffix, kaller)
@@ -85,11 +134,25 @@ def route_name_for(args, old_name, suffix, kaller)
                  args_locale.to_s.underscore
                elsif kaller.respond_to?("#{old_name}_#{current_locale_name}_#{suffix}")
                  current_locale_name
+               elsif fallback_locale = fallback_route_locale_name(current_locale_name, old_name, suffix, kaller)
+                 fallback_locale
                else
                  I18n.default_locale.to_s.underscore
                end
 
       "#{old_name}_#{locale}_#{suffix}"
     end
+
+    def fallback_route_locale_name(current_locale_name, old_name, suffix, kaller)
+      return nil unless RouteTranslator.config.deduplicate_routes
+
+      available_fallback_locales = I18n.fallbacks[current_locale_name].select do |fallback_locale|
+        kaller.respond_to?("#{old_name}_#{fallback_locale}_#{suffix}")
+      end
+
+      return nil if available_fallback_locales.empty?
+
+      available_fallback_locales.first
+    end
   end
 end