ruby-on-rails - 如何修复此创建功能？

我有一个函数，它将嵌套的属性分割成一个数组，这样就可以检查它们的唯一性，然后保存它们。问题是，我得到了一个Can't mass-assign protected attributes: _destroy错误，因为nested_form gem插入了一个隐藏的字段来突出显示应该删除哪些属性。
下面是*posts\u contoller.rb*create函数：

def create
   location_set = params[:post].delete(:locations_attributes) unless params[:post][:locations_attributes].blank?

   @post = current_blogger.blog_posts.new(params[:post])

   @post.locations = Location.find_or_initialize_location_set(location_set) unless location_set.nil?


 if @post.save
    redirect_to @post, notice: 'Blog post was successfully created.'
  else
    render action: "new"
  end
end

这是location.rb中的函数：

def self.find_or_initialize_location_set(location_set)
  #create a locations array
   locations = []
         locations = locations.delete_if { |elem| elem.flatten.empty? }

   location_set.each do |key, location|
       locations << find_or_initialize_by_name(location)
   end

 locations

 end

日志如下：

 Started POST "/blog/posts" for 127.0.0.1 at 2012-12-03 17:31:54 +0000
 Processing by Blogit::PostsController#create as HTML Parameters: {"utf8"=>"✓", "authenticity_token"=>"r74iCzC4tJgVI6FiCEH7XzfiTmaqKihF5JSs7Ow3MSI=", "post"=>{"title"=>"This
 is a post about Paris", "body"=>"This is a post about ParisThis is a post about Paris
 This is a post about ParisThis is a post about Paris", "tag_list"=>"",
 "locations_attributes"=>{"0"=>{"_destroy"=>"false", "name"=>"Paris", "longitude"=>"2.3522219", "latitude"=>"48.856614"}, "1354555760002"=>{"_destroy"=>"false", "name"=>"Los Angeles", "longitude"=>"-118.5155901", "latitude"=>"3
 4.03563310000001"}}}, "_wysihtml5_mode"=>"1", "name"=>"losds", "legname"=>"Los Angeles",    "longitude"=>"-118.5155901", "latitud
 e"=>"34.03563310000001", "commit"=>"Submit"}

 User Load (0.1ms)  SELECT "users".* FROM "users" WHERE "users"."id" = 1 LIMIT 1
 ActsAsTaggableOn::Tag Load (0.1ms)  SELECT "tags".* FROM "tags" INNER JOIN "taggings" ON  "tags"."id" = "taggings"."tag_id" W
 HERE "taggings"."taggable_id" IS NULL AND "taggings"."taggable_type" = 'Blogit::Post' AND  (taggings.context = 'tags' AND taggings.tagger_id IS NULL)

 Location Load (0.1ms)  SELECT "locations".* FROM "locations" WHERE "locations"."name" = 'Paris' LIMIT 1
 LOGGER LOCATIONS ARE[#<Location id: 768, name: "Paris", latitude: #<BigDecimal:7f86aadf6230,'0.48856614E2',18(45)>, longitude:
 #<BigDecimal:7f86aadf5f60,'0.23522219E1',18(45)>, post_id: nil, created_at: "2012-12-01 17:27:33", updated_at: "2012-12-01 17
 :27:33", notes: nil>]
 Location Load (0.2ms)  SELECT "locations".* FROM "locations" WHERE "locations"."name" = 'Los Angeles' LIMIT 1
 Completed 500 Internal Server Error in 97ms

  ActiveModel::MassAssignmentSecurity::Error (Can't mass-assign protected attributes: _destroy):
  app/models/location.rb:23:in `block in find_or_initialize_location_set'
  app/models/location.rb:21:in `each'
  app/models/location.rb:21:in `find_or_initialize_location_set'
  app/controllers/blogit/posts_controller.rb:79:in `create'

有什么建议可以让我像以前一样将delete函数包含在参数中，但这样我就不会得到Can't mass-assign protected attributes: _destroy错误吗？
谢谢！

最佳答案

你可以这样做：

def self.find_or_initialize_location_set(location_set)
  #create a locations array
  locations = []
  locations = locations.delete_if { |elem| elem.flatten.empty? }

  location_set.each do |key, location|
    if location.delete(:_destroy) == "1"
      locations.delete_if {|elem| elem[:name] == location[:name]}
    else
      locations << find_or_initialize_by_name(location)
    end
  end

  locations
end

对关联散列调用delete将修改散列并返回要删除的值（如果不存在则返回nil）。
或者，如果您需要在初始化的位置上进行删除，可以在那里执行：

def find_or_initialize_by_name_with_delete(location)
  if location.delete(:_destroy)
    do_delete
  end

  find_or_initialize_by_name(location)
end

关于ruby-on-rails - 如何修复此创建功能？，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/13688896/