pools: add ability to search for pools linking to given tag.

Add ability to search for pools linking to a given tag in the pool
description. Example:

    https://danbooru.donmai.us/pools?search[linked_to]=touhou

(This isn't actually exposed in the UI to avoid cluttering the pool
search form with rarely used options.)

Pools with broken links can be found here:

    https://danbooru.donmai.us/dtext_links?search[has_linked_tag]=No&search[has_linked_wiki]=No&search[model_type]=Pool

Lays the groundwork for fixing #4629.

app/logical/concerns/has_dtext_links.rb

@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+module HasDtextLinks
+  extend ActiveSupport::Concern
+
+  class_methods do
+    # Declare a field that has DText links. Any wiki links or external links
+    # contained in this field will be saved in the dtext_links table whenever
+    # the field is updated. This allows finding wiki pages, forum posts, and
+    # pool descriptions linking to a given tag.
+    #
+    # @param attribute [Symbol] the name of the DText field.
+    def has_dtext_links(attribute)
+      has_many :dtext_links, as: :model, dependent: :destroy
+      before_save :update_dtext_links, if: :dtext_links_changed?
+
+      define_method(:dtext_links_changed?) do
+        attribute_changed?(attribute) && DText.dtext_links_differ?(self[attribute], attribute_was(attribute))
+      end
+
+      define_method(:update_dtext_links) do
+        self.dtext_links = DtextLink.new_from_dtext(self[attribute])
+      end
+    end
+
+    # Return pages (e.g. wikis, forum posts, pool descriptions) that link to the given wiki page.
+    def linked_to(title)
+      where(dtext_links: DtextLink.where(model_type: name).wiki_link.where(link_target: WikiPage.normalize_title(title)))
+    end
+
+    # Return pages that don't link to the given wiki page.
+    def not_linked_to(title)
+      where.not(dtext_links: DtextLink.where(model_type: name).wiki_link.where(link_target: WikiPage.normalize_title(title)))
+    end
+  end
+end

app/models/application_record.rb

@@ -7,6 +7,7 @@ class ApplicationRecord < ActiveRecord::Base
   include Mentionable
   include Normalizable
   include ArrayAttribute
+  include HasDtextLinks
   extend HasBitFlags
   extend Searchable
 

app/models/dtext_link.rb

@@ -12,15 +12,16 @@ class DtextLink < ApplicationRecord
 
   scope :wiki_page, -> { where(model_type: "WikiPage") }
   scope :forum_post, -> { where(model_type: "ForumPost") }
+  scope :pool, -> { where(model_type: "Pool") }
 
   def self.visible(user)
     # XXX the double negation is to prevent postgres from choosing a bad query
     # plan (it doesn't know that most forum posts aren't mod-only posts).
-    wiki_page.or(forum_post.where.not(model_id: ForumPost.not_visible(user)))
+    wiki_page.or(forum_post.where.not(model_id: ForumPost.not_visible(user))).or(pool)
   end
 
   def self.model_types
-    %w[WikiPage ForumPost]
+    %w[WikiPage ForumPost Pool]
   end
 
   def self.new_from_dtext(dtext)

app/models/forum_post.rb

@@ -7,7 +7,6 @@ class ForumPost < ApplicationRecord
   belongs_to_updater
   belongs_to :topic, class_name: "ForumTopic", inverse_of: :forum_posts
 
-  has_many :dtext_links, as: :model, dependent: :destroy
   has_many :moderation_reports, as: :model
   has_many :votes, class_name: "ForumPostVote"
   has_one :tag_alias
@@ -16,7 +15,6 @@ class ForumPost < ApplicationRecord
 
   validates :body, presence: true, length: { maximum: 200_000 }, if: :body_changed?
 
-  before_save :update_dtext_links, if: :dtext_links_changed?
   before_create :autoreport_spam
   after_create :update_topic_updated_at_on_create
   after_update :update_topic_updated_at_on_update_for_original_posts
@@ -31,6 +29,7 @@ class ForumPost < ApplicationRecord
   after_create_commit :async_send_discord_notification
 
   deletable
+  has_dtext_links :body
   mentionable(
     message_field: :body,
     title: ->(_user_name) {%{#{creator.name} mentioned you in topic ##{topic_id} (#{topic.title})}},
@@ -112,14 +111,6 @@ class ForumPost < ApplicationRecord
     update_topic_updated_at_on_undelete
   end
 
-  def dtext_links_changed?
-    body_changed? && DText.dtext_links_differ?(body, body_was)
-  end
-
-  def update_dtext_links
-    self.dtext_links = DtextLink.new_from_dtext(body)
-  end
-
   def update_topic_updated_at_on_delete
     max = ForumPost.where(:topic_id => topic.id, :is_deleted => false).order("updated_at desc").first
     if max

app/models/pool.rb

@@ -15,6 +15,7 @@ class Pool < ApplicationRecord
   after_save :create_version
 
   deletable
+  has_dtext_links :description
 
   scope :series, -> { where(category: "series") }
   scope :collection, -> { where(category: "collection") }
@@ -37,7 +38,7 @@ class Pool < ApplicationRecord
     end
 
     def search(params)
-      q = search_attributes(params, :id, :created_at, :updated_at, :is_deleted, :name, :description, :post_ids)
+      q = search_attributes(params, :id, :created_at, :updated_at, :is_deleted, :name, :description, :post_ids, :dtext_links)
       q = q.text_attribute_matches(:description, params[:description_matches])
 
       if params[:post_tags_match]
@@ -48,6 +49,14 @@ class Pool < ApplicationRecord
         q = q.name_matches(params[:name_matches])
       end
 
+      if params[:linked_to].present?
+        q = q.linked_to(params[:linked_to])
+      end
+
+      if params[:not_linked_to].present?
+        q = q.not_linked_to(params[:not_linked_to])
+      end
+
       case params[:category]
       when "series"
         q = q.series

app/models/wiki_page.rb

@@ -5,7 +5,6 @@ class WikiPage < ApplicationRecord
 
   META_WIKIS = ["list_of_", "tag_group:", "pool_group:", "howto:", "about:", "help:", "template:"]
 
-  before_save :update_dtext_links, if: :dtext_links_changed?
   after_save :create_version
 
   normalize :title, :normalize_title
@@ -22,9 +21,9 @@ class WikiPage < ApplicationRecord
   has_one :tag, :foreign_key => "name", :primary_key => "title"
   has_one :artist, -> { active }, foreign_key: "name", primary_key: "title"
   has_many :versions, -> {order("wiki_page_versions.id ASC")}, :class_name => "WikiPageVersion", :dependent => :destroy
-  has_many :dtext_links, as: :model, dependent: :destroy
 
   deletable
+  has_dtext_links :body
 
   module SearchMethods
     def find_by_id_or_title(id)
@@ -58,14 +57,6 @@ class WikiPage < ApplicationRecord
       end
     end
 
-    def linked_to(title)
-      where(dtext_links: DtextLink.wiki_page.wiki_link.where(link_target: normalize_title(title)))
-    end
-
-    def not_linked_to(title)
-      where.not(dtext_links: DtextLink.wiki_page.wiki_link.where(link_target: normalize_title(title)))
-    end
-
     def default_order
       order(updated_at: :desc)
     end
@@ -213,14 +204,6 @@ class WikiPage < ApplicationRecord
     end
   end
 
-  def dtext_links_changed?
-    body_changed? && DText.dtext_links_differ?(body, body_was)
-  end
-
-  def update_dtext_links
-    self.dtext_links = DtextLink.new_from_dtext(body)
-  end
-
   def tags
     titles = DText.parse_wiki_titles(body).uniq
     tags = Tag.nonempty.where(name: titles).pluck(:name)

app/views/dtext_links/index.html.erb

@@ -2,7 +2,7 @@
   <div id="a-index">
     <%= search_form_for(dtext_links_path) do |f| %>
       <%= f.input :link_target_ilike, label: "Link", hint: "Use * for wildcard", input_html: { value: params[:search][:link_target_ilike], data: { autocomplete: "wiki-page" } } %>
-      <%= f.input :model_type, label: "Page Type", collection: [["Wiki Page", "WikiPage"], ["Forum Post", "ForumPost"]], include_blank: true, selected: params[:search][:model_type] %>
+      <%= f.input :model_type, label: "Page Type", collection: DtextLink.model_types.map { [_1.titleize, _1] }, include_blank: true, selected: params[:search][:model_type] %>
       <%= f.input :link_type, label: "Link Type", collection: [["Wiki", "0"], ["External", "1"]], include_blank: true, selected: params[:search][:link_type] %>
       <%= f.input :has_linked_wiki, label: "Wiki Exists?", collection: ["Yes", "No"], include_blank: true, selected: params[:search][:has_linked_wiki] %>
       <%= f.input :has_linked_tag, label: "Tag Exists?", collection: ["Yes", "No"], include_blank: true, selected: params[:search][:has_linked_tag] %>
@@ -16,8 +16,8 @@
             <%= link_to(dtext_link.model.title, dtext_link.model) %>
             <%= link_to("»", dtext_links_path(search: { model_type: "WikiPage", model: { title: dtext_link.model.title }})) %>
           </span>
-        <% elsif dtext_link.model_type == "ForumPost" %>
-          <%= link_to("forum ##{dtext_link.model_id}", dtext_link.model) %>
+        <% else %>
+          <%= link_to(dtext_link.model.dtext_shortlink, dtext_link.model) %>
         <% end %>
       <% end %>
 

script/fixes/090_create_pool_dtext_links.rb

@@ -0,0 +1,9 @@
+#!/usr/bin/env ruby
+
+require_relative "base"
+
+with_confirmation do
+  Pool.find_each do |pool|
+    pool.update_dtext_links
+  end
+end

test/functional/dtext_links_controller_test.rb

@@ -6,6 +6,7 @@ class DtextLinksControllerTest < ActionDispatch::IntegrationTest
     as(@user) do
       @wiki = create(:wiki_page, title: "case", body: "[[test]]")
       @forum = create(:forum_post, topic: build(:forum_topic, title: "blah"), body: "[[case]]")
+      @pool = create(:pool, description: "[[case]]")
       create(:tag, name: "test")
     end
   end
@@ -16,13 +17,14 @@ class DtextLinksControllerTest < ActionDispatch::IntegrationTest
       assert_response :success
     end
 
-    should respond_to_search({}).with { @forum.dtext_links + @wiki.dtext_links }
+    should respond_to_search({}).with { @pool.dtext_links + @forum.dtext_links + @wiki.dtext_links }
 
     context "using includes" do
       should respond_to_search(model_type: "WikiPage").with { @wiki.dtext_links }
       should respond_to_search(model_type: "ForumPost").with { @forum.dtext_links }
+      should respond_to_search(model_type: "Pool").with { @pool.dtext_links }
       should respond_to_search(has_linked_tag: "true").with { @wiki.dtext_links }
-      should respond_to_search(has_linked_wiki: "true").with { @forum.dtext_links }
+      should respond_to_search(has_linked_wiki: "true").with { @pool.dtext_links + @forum.dtext_links }
       should respond_to_search(ForumPost: {topic: {title_matches: "blah"}}).with { @forum.dtext_links }
       should respond_to_search(ForumPost: {topic: {title_matches: "nah"}}).with { [] }
     end

test/functional/pools_controller_test.rb

@@ -9,7 +9,7 @@ class PoolsControllerTest < ActionDispatch::IntegrationTest
       end
       as(@user) do
         @post = create(:post)
-        @pool = create(:pool)
+        @pool = create(:pool, name: "pool", description: "[[touhou]]")
       end
     end
 
@@ -19,17 +19,15 @@ class PoolsControllerTest < ActionDispatch::IntegrationTest
         assert_response :success
       end
 
-      should "list all pools (with search)" do
-        get pools_path, params: {:search => {:name_matches => @pool.name}}
-        assert_response :success
-      end
-
       should "render for a sitemap" do
         get pools_path(format: :sitemap)
         assert_response :success
         assert_equal(Pool.count, response.parsed_body.css("urlset url loc").size)
       end
 
+      should respond_to_search(name_matches: "pool").with { @pool }
+      should respond_to_search(linked_to: "touhou").with { @pool }
+      should respond_to_search(not_linked_to: "touhou").with { [] }
     end
 
     context "show action" do