Merge pull request #1845 from codidact/0valt/caching

Fix N+1 query on tag_synonyms when loading lists of tags

Author: ArtOfCode-

app/controllers/tags_controller.rb

@@ -10,11 +10,16 @@ def index
     @tag_set = if params[:tag_set].present?
                  TagSet.find(params[:tag_set])
                end
+
     @tags = if params[:term].present?
               (@tag_set&.tags || Tag).search(params[:term])
             else
               (@tag_set&.tags || Tag.all).order(:name)
-            end.includes(:tag_synonyms).paginate(page: params[:page], per_page: 50)
+            end
+
+    @tags = @tags.list_includes
+                 .paginate(page: params[:page], per_page: 50)
+
     respond_to do |format|
       format.json do
         render json: @tags.to_json(include: { tag_synonyms: { only: :name } })
@@ -38,7 +43,7 @@ def category
               @tag_set.tags.where(excerpt: ['', nil])
             else
               @tag_set.tags
-            end
+            end.list_includes
 
     table = params[:hierarchical].present? ? 'tags_paths' : 'tags'
 

app/models/tag.rb

@@ -18,6 +18,9 @@ class Tag < ApplicationRecord
   validate :synonym_unique
   validates :name, uniqueness: { scope: [:tag_set_id], case_sensitive: false }
 
+  # scopes
+  scope :list_includes, -> { includes(:tag_synonyms) }
+
   # Fuzzy-searches tags by name, excerpt, and synonym name
   # @param term [String] search term
   # @return [ActiveRecord::Relation<Tag>]