我该如何修复这个创建function？
我有一个函数将嵌套属性拆分成一个数组，以便检查它们的唯一性，然后保存它们。 问题是，我得到一个Can't mass-assign protected attributes: _destroy错误，因为nested_form gem插入一个hidden_field来突出显示应删除哪些属性。
这是* Posts_Contoller.rb *创建函数：
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
这是日志：
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: #, longitude: #, 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'
关于我如何适应这个的任何建议，包括删除函数在params中，但所以我没有得到Can't mass-assign protected attributes: _destroy错误？
谢谢！
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
在关联的哈希上调用delete将修改哈希值并返回您要删除的值（如果不存在则返回nil ）。
或者，如果您需要在初始化位置删除，您可以在那里执行：
def find_or_initialize_by_name_with_delete(location) if location.delete(:_destroy) do_delete end find_or_initialize_by_name(location) end
您可以通过将此错误添加到您的位置模型来消除此错误：
# NOT PERSISTENT attr_accessor :_destroy # ... attr_accessible :_destroy
如果没有这个， _destroy属性就会受到质量分配的保护，当你尝试为它赋值时，无论如何都会抛出exception。