为什么acts-as-taggable-on标签会在更新过程中丢失？

Question

我在Ruby on Rails应用程序中使用了acts as-taggable-on，允许用户将标签添加到他们的联系人列表中(就像带标签的地址簿一样)。对于使用标准RESTful路径contacts/new、contacts/[:id]、contacts/:id/edit等的用户来说，添加/更新带有标签的联系人可以完美地工作。

我现在正在尝试添加功能，以便用户可以发送电子邮件给联系人，要求他们确认并完成他们的详细信息。电子邮件请求包括一个页面的链接，该页面构建在不同的控制器上，该页面显示一个表单(也称为“确认表单”)，其中包含所有联系方式详细信息，但不包括标签(对用户而言是个人的)。

电子邮件链接的形式为：

contact_confirmation/[:id]/edit?contact_id=[:contact_id]

其中，[:id]是一个令牌，用于一次性访问联系人以更新其详细信息(这类似于非常标准的密码重置)。

确认表单会正确更新所有联系人详细信息，但由于某些原因，标签会丢失。两种情况下的params[]是相同的，更新方法也是相同的。

查看日志，它们在第一次提交之前都是相同的。然后确认表单启动一个新过程(BEGIN)并删除标记：

(0.2ms)  BEGIN
CACHE ActsAsTaggableOn::Tag Load (0.0ms)  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 = 'tags' AND taggings.tagger_id IS NULL)  [["taggable_id", 9], ["taggable_type", "Contact"]]
CACHE ActsAsTaggableOn::Tag Load (0.0ms)  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 = 'tags' AND taggings.tagger_id IS NULL)  [["taggable_id", 9], ["taggable_type", "Contact"]]
CACHE ActsAsTaggableOn::Tag Load (0.0ms)  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"."tagger_id" = $3 AND "taggings"."tagger_type" = $4 AND "taggings"."context" = $5  [["taggable_id", 9], ["taggable_type", "Contact"], ["tagger_id", 1], ["tagger_type", "User"], ["context", "tags"]]
ActsAsTaggableOn::Tagging Load (0.6ms)  SELECT "taggings".* FROM "taggings" WHERE "taggings"."taggable_id" = $1 AND "taggings"."taggable_type" = $2 AND "taggings"."tagger_type" = $3 AND "taggings"."tagger_id" = $4 AND "taggings"."tag_id" IN (5, 43, 44) AND "taggings"."context" = $5  [["taggable_id", 9], ["taggable_type", "Contact"], ["tagger_type", "User"], ["tagger_id", 1], ["context", "tags"]]
SQL (0.5ms)  DELETE FROM "taggings" WHERE "taggings"."id" = $1  [["id", 152]]
ActsAsTaggableOn::Tag Load (0.5ms)  SELECT  "tags".* FROM "tags" WHERE "tags"."id" = $1 LIMIT $2  [["id", 5], ["LIMIT", 1]]
SQL (0.8ms)  UPDATE "tags" SET "taggings_count" = COALESCE("taggings_count", 0) - 1 WHERE "tags"."id" = $1  [["id", 5]]
ActsAsTaggableOn::Tag Load (1.3ms)  SELECT  "tags".* FROM "tags" WHERE "tags"."id" = $1 LIMIT $2  [["id", 5], ["LIMIT", 1]]
SQL (0.8ms)  DELETE FROM "taggings" WHERE "taggings"."id" = $1  [["id", 153]]
ActsAsTaggableOn::Tag Load (0.4ms)  SELECT  "tags".* FROM "tags" WHERE "tags"."id" = $1 LIMIT $2  [["id", 43], ["LIMIT", 1]]
SQL (0.5ms)  UPDATE "tags" SET "taggings_count" = COALESCE("taggings_count", 0) - 1 WHERE "tags"."id" = $1  [["id", 43]]
ActsAsTaggableOn::Tag Load (0.4ms)  SELECT  "tags".* FROM "tags" WHERE "tags"."id" = $1 LIMIT $2  [["id", 43], ["LIMIT", 1]]
ActsAsTaggableOn::Tagging Load (0.3ms)  SELECT "taggings".* FROM "taggings" WHERE "taggings"."tag_id" = $1  [["tag_id", 43]]
SQL (0.5ms)  DELETE FROM "tags" WHERE "tags"."id" = $1  [["id", 43]]
SQL (0.5ms)  DELETE FROM "taggings" WHERE "taggings"."id" = $1  [["id", 154]]
ActsAsTaggableOn::Tag Load (0.4ms)  SELECT  "tags".* FROM "tags" WHERE "tags"."id" = $1 LIMIT $2  [["id", 44], ["LIMIT", 1]]
SQL (0.9ms)  UPDATE "tags" SET "taggings_count" = COALESCE("taggings_count", 0) - 1 WHERE "tags"."id" = $1  [["id", 44]]
ActsAsTaggableOn::Tag Load (0.4ms)  SELECT  "tags".* FROM "tags" WHERE "tags"."id" = $1 LIMIT $2  [["id", 44], ["LIMIT", 1]]
ActsAsTaggableOn::Tagging Load (0.5ms)  SELECT "taggings".* FROM "taggings" WHERE "taggings"."tag_id" = $1  [["tag_id", 44]]
SQL (2.0ms)  DELETE FROM "tags" WHERE "tags"."id" = $1  [["id", 44]]
ActsAsTaggableOn::Tag Load (3.1ms)  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"."tagger_id" = $3 AND "taggings"."tagger_type" = $4 AND "taggings"."context" = $5  [["taggable_id", 9], ["taggable_type", "Contact"], ["tagger_id", 1], ["tagger_type", "User"], ["context", "tags"]]
(1.2ms)  COMMIT

有人能帮我弄清楚为什么会这样吗？谢谢。

Answer 1

回答者：https://stackoverflow.com/a/25018540/6569994

我必须向联系人模型上的set_tag_owner添加if tag_list_changed?条件：

def set_tag_owner
  if tag_list_changed?
    set_owner_tag_list_on(account, :tags, tag_list)
    self.tag_list = nil
  end
end

我认为在正常情况下，每次都必须剥离并重新添加标签。