acts-as-taggable-on gem 不清除标签的奇怪行为

Question

我有一个名为 Recipe 的模型，它使用了被报告的 acts-as-taggable-on gem to add taggings to the recipes. The weird behavior is when I edit and update the recipe via the controller, the recipe taggings are added instead of updating to proper taggings. There was a similar Github issue，但没有任何人回复。我的 acts-as-taggable-on gem 版本是 3.2.6.

例如，我的食谱有三个标签：fruit、fruit 和 vegetables。 fruit 标签不相关，所以我在 f.tag_list 输入字段中删除了这两个 fruit 标签，只包含 vegetables.

Processing by Users::RecipesController#update as JS
Parameters: {"utf8"=>"✓", "recipe"=>{"image_ids"=>"46746", "cover_image_id"=>"46746",
"name"=>"Cauliflower", "description"=>"this is the description", "preparation_time_hr"=>"0",
"preparation_time_min"=>"50", "servings"=>"4", 
"category_ids"=>"", "cuisine_ids"=>"", "tag_list"=>"vegetables", "ingredients"=>....}

users/recipes_controller.rb

def update
  if @recipe.update_attributes(recipe_params)
    if params[:publish_recipe] && params[:publish_recipe] == "true"
      update_status!(:publish!)
    end
    redirect_to user_recipes_url
  else
    respond_to do |format|
      format.html{ render "edit" }
      format.js { render partial: "shared/flash_message", locals: { flash_type: "error", flash_message: "#{@recipe.errors.full_messages.to_sentence}" } }
    end
  end
end

recipe_params 包括 tag_list 作为允许的参数。

def recipe_params
  params.required(:recipe).permit(:name, :category_ids, :cuisine_ids, :tag_list, :preparation_time_hr,
  :cover_image_id, :preparation_time_min, :servings, :description, :image_ids, :commentable,
  ingredients_attributes: [:id, :name, :_destroy],
  instructions_attributes: [:id, :text, :_destroy, image_attributes: [:id, :picture, :_destroy]]
) rescue {}
end

但最终旧标签没有被删除，新标签已添加到列表中：fruit、fruit、vegetables、vegetables。

另一件奇怪的事情是，当我试图查看食谱的 tag_list 时，它是一个空数组。尝试在 rails 控制台中编辑 tag_list，它添加了另一个标记，但是当我编辑 r.reload 时，tag_list 它仍然是一个空数组。现在菜谱和标签的关系是这样的：

r = Recipe.find(20980)
[56] pry(main)> r.tag_list
 ActsAsTaggableOn::Tag Load (14.9ms)  SELECT `tags`.* FROM `tags` INNER JOIN `taggings` ON `tags`.`id` = `taggings`.`tag_id` WHERE `taggings`.`taggable_id` = 20980 AND `taggings`.`taggable_type` = 'Recipe' AND (taggings.context = 'tags' AND taggings.tagger_id IS NULL)
=> []
[57] pry(main)> r.tags
=> [#<ActsAsTaggableOn::Tag id: 2, name: "fruit", taggings_count: 1138, tagger_id: nil, tagger_type: nil, created_at: "2015-07-25 15:47:20", updated_at: "2015-07-25 15:47:53">,
 #<ActsAsTaggableOn::Tag id: 2, name: "fruit", taggings_count: 1138, tagger_id: nil, tagger_type: nil, created_at: "2015-07-25 15:47:20", updated_at: "2015-07-25 15:47:53">,
 #<ActsAsTaggableOn::Tag id: 531, name: "vegetables", taggings_count: 21, tagger_id: nil, tagger_type: nil, created_at: "2015-07-25 15:56:15", updated_at: "2015-07-25 15:56:16">,
 #<ActsAsTaggableOn::Tag id: 531, name: "vegetables", taggings_count: 21, tagger_id: nil, tagger_type: nil, created_at: "2015-07-25 15:56:15", updated_at: "2015-07-25 15:56:16">,
 #<ActsAsTaggableOn::Tag id: 531, name: "vegetables", taggings_count: 21, tagger_id: nil, tagger_type: nil, created_at: "2015-07-25 15:56:15", updated_at: "2015-07-25 15:56:16">]
[58] pry(main)> r.taggings
  ActsAsTaggableOn::Tagging Load (35.8ms)  SELECT `taggings`.* FROM `taggings`  WHERE `taggings`.`taggable_id` = 20980 AND `taggings`.`taggable_type` = 'Recipe'
=> [#<ActsAsTaggableOn::Tagging id: 20408, tag_id: 2, taggable_id: 20980, taggable_type: "Recipe", tagger_id: 200422, tagger_type: "User", context: "tags", created_at: "2015-08-21 03:56:13">,
 #<ActsAsTaggableOn::Tagging id: 20409, tag_id: 2, taggable_id: 20980, taggable_type: "Recipe", tagger_id: 200422, tagger_type: "User", context: "tags", created_at: "2015-08-21 03:56:14">,
 #<ActsAsTaggableOn::Tagging id: 20410, tag_id: 531, taggable_id: 20980, taggable_type: "Recipe", tagger_id: 200422, tagger_type: "User", context: "tags", created_at: "2015-08-21 04:01:36">,
 #<ActsAsTaggableOn::Tagging id: 20411, tag_id: 531, taggable_id: 20980, taggable_type: "Recipe", tagger_id: 200422, tagger_type: "User", context: "tags", created_at: "2015-08-21 04:47:38">,
 #<ActsAsTaggableOn::Tagging id: 20412, tag_id: 531, taggable_id: 20980, taggable_type: "Recipe", tagger_id: 200422, tagger_type: "User", context: "tags", created_at: "2015-08-21 04:53:38">]

tag_list数据库查询也很奇怪，为什么查询包含这个taggings.tagger_id IS NULL？

我对这个 gem 还是个新手，知道如何使用 gem 方法正确更新标签吗？我希望我可以避免使用我自己的代码更新标签以避免进一步的问题。注意我的Recipe模型是paper_trailgem版本的，希望与这个问题无关。

Answer 1

由于网上没有解决办法，而且我只在Recipe上使用这个taggable，所以我现在手动调用一个方法来在模型保存后重新更新标签。

def update_tags(tag_list)
  self.taggings.destroy_all
  list = tag_list.split(",")
  list.each do |t|
    tag = Tag.find_or_create_by(name: t)
    self.taggings.create(tag_id: tag.id, context: "tags")
  end
  return self.taggings
end

我仍然认为这个问题有更好的解决方案，我愿意接受替代方案作为最佳答案。

Answer 2

我在 act-as-taggable-on 文档中看不到任何关于当 tags_list 作为参数进入 update_attributes 方法时会发生什么的内容，但在你的情况下似乎添加标签而不删除现有标签。我确实在文档中注意到 tag_list 可以分配给 = 来替换现有标签：

You can also add and remove tags by direct assignment. Note this will remove existing tags so use it with attention.
@user.tag_list = "awesome, slick, hefty"
@user.save

所以你可以在你的更新方法中做到这一点

def update
  if @recipe.update_attributes(recipe_params)
    @recipe.tag_list = recipe_params["tag_list"]
    @recipe.save
    ...
  else
    ...
  end
end

acts-as-taggable-on gem 不清除标签的奇怪行为

Weird behaviors on acts-as-taggable-on gem of not clearing taggings

ruby

ruby-on-rails

acts-as-taggable-on

ruby-on-rails-4