#321

backend/app/controllers/tag_versions_controller.rb

@@ -39,18 +39,23 @@ class TagVersionsController < ApplicationController
       cur_aliases = split_values(row.aliases)
       prev_aliases = split_values(row.attributes['prev_aliases'])
 
-      cur_parent_tags =
-          TagRepr.many(
-              Tag
-              .includes(:tag_name, :materials, { tag_name: :wiki_page })
-              .where(id: split_parent_tag_ids(row.parent_tag_ids))
-              .to_a)
-      prev_parent_tags =
-          TagRepr.many(
-              Tag
-              .includes(:tag_name, :materials, { tag_name: :wiki_page })
-              .where(id: split_parent_tag_ids(row.attributes['prev_parent_tag_ids']))
-              .to_a)
+      cur_parent_tag_ids = split_parent_tag_ids(row.parent_tag_ids)
+      prev_parent_tag_ids = split_parent_tag_ids(row.attributes['prev_parent_tag_ids'])
+
+      all_parent_tag_ids = (cur_parent_tag_ids | prev_parent_tag_ids)
+
+      tags_by_id =
+          Tag
+          .includes(:tag_name, :materials, { tag_name: :wiki_page })
+          .where(id: all_parent_tag_ids)
+          .index_by(&:id)
+
+      parent_tags =
+          build_version_values(cur_parent_tag_ids, prev_parent_tag_ids, key: :tag_id)
+          .map do |h|
+            { tag: TagRepr.base(tags_by_id[h[:tag_id]]),
+              type: h[:type] }
+          end
 
       { tag_id: row.tag_id,
         version_no: row.version_no,
@@ -58,7 +63,7 @@ class TagVersionsController < ApplicationController
         name: { current: row.name, prev: row.attributes['prev_name'] },
         category: { current: row.category, prev: row.attributes['prev_category'] },
         aliases: build_version_values(cur_aliases, prev_aliases, key: :name),
-        parent_tags: build_version_values(cur_parent_tags, prev_parent_tags, key: :tag),
+        parent_tags:,
         created_at: row.created_at.iso8601,
         created_by_user: row.created_by_user_id &&
                          { id: row.created_by_user_id,