ruby-on-rails - 如何使用 pg_search 搜索对象的虚拟属性？

Question

我有一个 Node 类，我在上面设置了 acts_as_taggable，所以我可以将 user_tags 添加到任何节点。我的 Node 模型也有一个方法，可以查找 user_tag_list 中所有用户的实际 User 记录。这是一个例子:

[32] pry(main)> m = Node.find(85)
  Node Load (8.6ms)  SELECT  "nodes".* FROM "nodes"  WHERE "nodes"."id" = $1 LIMIT 1  [["id", 85]]
=> #<Node id: 85, name: "House Fire 2", family_tree_id: 57, user_id: 57, media_id: 228, media_type: "Video", created_at: "2015-05-15 00:20:26", updated_at: "2015-05-20 01:06:34">
[33] pry(main)> m.user_tags
  ActsAsTaggableOn::Tag Load (3.8ms)  SELECT "tags".* FROM "tags" INNER JOIN "taggings" ON "tags"."id" = "taggings"."tag_id" WHERE "taggings"."taggable_id" = $1 AND "taggings"."taggable_type" = $2 AND "taggings"."context" = 'user_tags'  [["taggable_id", 85], ["taggable_type", "Node"]]
=> [#<ActsAsTaggableOn::Tag id: 4, name: "gerry@test.com", taggings_count: 1>, #<ActsAsTaggableOn::Tag id: 6, name: "danny@test.com", taggings_count: 1>]
[34] pry(main)> m.user_tag_list
  ActsAsTaggableOn::Tag Load (0.8ms)  SELECT "tags".* FROM "tags" INNER JOIN "taggings" ON "tags"."id" = "taggings"."tag_id" WHERE "taggings"."taggable_id" = $1 AND "taggings"."taggable_type" = $2 AND (taggings.context = 'user_tags' AND taggings.tagger_id IS NULL)  [["taggable_id", 85], ["taggable_type", "Node"]]
=> ["gerry@test.com", "danny@test.com"]
[35] pry(main)> m.tagged_users
  User Load (5.7ms)  SELECT  "users".* FROM "users"  WHERE "users"."email" = 'gerry@test.com' LIMIT 1
  User Load (2.1ms)  SELECT  "users".* FROM "users"  WHERE "users"."email" = 'danny@test.com' LIMIT 1
=> [#<User id: 52, email: "gerry@test.com", encrypted_password: "$2a$10$KaX1kvtIw1.jGITnt9Czqeq3xTzhY3OM052NSHsL5Lf...", reset_password_token: nil, reset_password_sent_at: nil, remember_created_at: nil, sign_in_count: 5, current_sign_in_at: "2015-04-03 17:10:28", last_sign_in_at: "2015-04-03 00:38:24", current_sign_in_ip: "127.0.0.1", last_sign_in_ip: "127.0.0.1", created_at: "2015-03-05 01:36:31", updated_at: "2015-04-03 17:10:28", first_name: "Gerry ", confirmation_token: nil, confirmed_at: "2015-03-05 01:36:52", confirmation_sent_at: nil, unconfirmed_email: nil, invitation_relation: "uncle", avatar: nil, invitation_token: nil, invitation_created_at: "2015-03-05 01:36:31", invitation_sent_at: "2015-03-05 01:36:31", invitation_accepted_at: "2015-03-05 01:36:52", invitation_limit: nil, invited_by_id: 1, invited_by_type: "User", invitations_count: 0, bio: nil, last_name: "Atrick", gender: 0>,
 #<User id: 58, email: "danny@test.com", encrypted_password: "$2a$10$ZpzLH17iFrOXzH4U/pOX.e4nwN.9IJ1s1Ap/zQglk9K...", reset_password_token: nil, reset_password_sent_at: nil, remember_created_at: nil, sign_in_count: 6, current_sign_in_at: "2015-05-26 04:36:32", last_sign_in_at: "2015-04-03 00:14:55", current_sign_in_ip: "127.0.0.1", last_sign_in_ip: "127.0.0.1", created_at: "2015-03-12 03:39:28", updated_at: "2015-05-26 04:36:32", first_name: "Daniel", confirmation_token: nil, confirmed_at: "2015-03-12 05:46:18", confirmation_sent_at: nil, unconfirmed_email: nil, invitation_relation: "son", avatar: nil, invitation_token: nil, invitation_created_at: "2015-03-12 03:39:28", invitation_sent_at: "2015-03-12 03:39:28", invitation_accepted_at: "2015-03-12 05:46:18", invitation_limit: nil, invited_by_id: 57, invited_by_type: "User", invitations_count: 0, bio: nil, last_name: "Marty", gender: 0>]

因此，理想情况下，我想要做的是允许用户搜索 say Gerry，它会从上面的示例中返回 Node.id = 85，因为Node.id = 85 有一个名字为 Gerry 的用户标签。

这是我在 Node 上现有的 pg_search:

  pg_search_scope :node_search, against: [:name, :user_id, :circa],
    using: { tsearch: { any_word: true} },
    :associated_against => {
      comments: [:message],
      user: [:first_name, :last_name, :email],
      memberships: [:relation]
    }

我觉得我应该可以使用 pg_search 的动态范围，但我不太理解它。

我将如何实现这一点？

Answer 1

事实证明，答案非常简单。

假设这是我的 Node 模型中 acts-as-taggable-on 的声明:

acts_as_taggable_on :user_tags

解决方案就是在 pg_search 声明中添加这一列，如下所示:

  include PgSearch
  pg_search_scope :node_search, against: [:name, :user_id, :circa],
    using: { tsearch: { any_word: true, dictionary: :english} },
    :associated_against => {
      comments: [:message],
      user: [:first_name, :last_name, :email],
      memberships: [:relation],
      user_tags: [:name]
    }

请注意，我必须在 user_tags 中指定字段(即 :name 属性)。

现在，它像我想要的那样搜索 :user_tags 的虚拟属性。