Activerecord 唯一性的嵌套验证在rails 4项目中不起作用

我有两个模型-类别和属性与许多关联。我使用嵌套形式的gem。所以，类别有很多属性。当我创建新类别时，我可以创建属性

类别模型Category.rb：

正如您所看到的，属性模型中存在唯一性：真正的验证。 当我试图使用rails控制台或在“类别编辑”页面上创建相同的属性时，它会给出类似于错误的属性，该属性的名称已经存在。这是正确的，应该是正确的

但在“类别新建”页面上，当我创建与您在屏幕截图中看到的相同属性时，它不会给我错误，验证不起作用，它会创建具有两个相同属性的新类别。。。。发生了什么？请帮忙

下面是日志：

Started POST "/categories" for 127.0.0.1 at 2014-09-01 14:28:19 +0300
Processing by CategoriesController#create as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"AFf8upQco8ZqJBS8QdpU9RIRpvAW1VLnBSm1bw6rxss=", "category"=>{"title"=>"Category", "description"=>"category description", "order"=>"12345", "icon"=>"http://4.bp.blogspot.com/-LOX6N2kXXaY/T5UtocrGRnI/AAAAAAAAAFU/EW_OZTHT1PI/s1600/1210167310_174374.jpg", "parent_id"=>"", "properties_attributes"=>{"1409570848547"=>{"title"=>"same properties", "_destroy"=>"false"}, "1409570857024"=>{"title"=>"same properties", "_destroy"=>"false"}}}, "commit"=>"Create Category"}
  User Load (0.5ms)  SELECT  "users".* FROM "users"  WHERE "users"."id" = 1  ORDER BY "users"."id" ASC LIMIT 1
   (0.4ms)  SELECT "categories"."id", "categories"."title" FROM "categories"
  CACHE (0.0ms)  SELECT "categories"."id", "categories"."title" FROM "categories"
   (0.2ms)  BEGIN
  Property Exists (0.4ms)  SELECT  1 AS one FROM "properties"  WHERE "properties"."title" = 'same properties' LIMIT 1
  CACHE (0.0ms)  SELECT  1 AS one FROM "properties"  WHERE "properties"."title" = 'same properties' LIMIT 1
  Category Exists (0.6ms)  SELECT  1 AS one FROM "categories"  WHERE "categories"."title" = 'Category' LIMIT 1
  SQL (0.5ms)  INSERT INTO "categories" ("created_at", "description", "icon", "order", "title", "updated_at") VALUES ($1, $2, $3, $4, $5, $6) RETURNING "id"  [["created_at", "2014-09-01 11:28:19.908849"], ["description", "category description"], ["icon", "http://4.bp.blogspot.com/-LOX6N2kXXaY/T5UtocrGRnI/AAAAAAAAAFU/EW_OZTHT1PI/s1600/1210167310_174374.jpg"], ["order", 12345], ["title", "Category"], ["updated_at", "2014-09-01 11:28:19.908849"]]
  SQL (0.3ms)  INSERT INTO "properties" ("created_at", "title", "updated_at") VALUES ($1, $2, $3) RETURNING "id"  [["created_at", "2014-09-01 11:28:19.910971"], ["title", "same properties"], ["updated_at", "2014-09-01 11:28:19.910971"]]
  SQL (0.4ms)  INSERT INTO "categories_properties" ("category_id", "created_at", "property_id", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "id"  [["category_id", 77], ["created_at", "2014-09-01 11:28:19.921763"], ["property_id", 90], ["updated_at", "2014-09-01 11:28:19.921763"]]
  SQL (0.4ms)  INSERT INTO "properties" ("created_at", "title", "updated_at") VALUES ($1, $2, $3) RETURNING "id"  [["created_at", "2014-09-01 11:28:19.947583"], ["title", "same properties"], ["updated_at", "2014-09-01 11:28:19.947583"]]
  SQL (0.4ms)  INSERT INTO "categories_properties" ("category_id", "created_at", "property_id", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "id"  [["category_id", 77], ["created_at", "2014-09-01 11:28:19.950243"], ["property_id", 91], ["updated_at", "2014-09-01 11:28:19.950243"]]
   (0.5ms)  COMMIT
Redirected to http://0.0.0.0:3000/categories/77
Completed 302 Found in 129ms (ActiveRecord: 21.8ms)

---

将验证方法添加到类别模型：

  def properties_uniq? params
    properties = params.map{ |_,property| property[:title] }
    if properties.uniq.length < properties.length
      errors.add(:category, "Properties duplication are not allowed." ) 
      return false
    end
    true
  end 

Started POST "/categories" for 127.0.0.1 at 2014-09-01 14:28:19 +0300
Processing by CategoriesController#create as HTML
  Parameters: {"utf8"=>"✓", "authenticity_token"=>"AFf8upQco8ZqJBS8QdpU9RIRpvAW1VLnBSm1bw6rxss=", "category"=>{"title"=>"Category", "description"=>"category description", "order"=>"12345", "icon"=>"http://4.bp.blogspot.com/-LOX6N2kXXaY/T5UtocrGRnI/AAAAAAAAAFU/EW_OZTHT1PI/s1600/1210167310_174374.jpg", "parent_id"=>"", "properties_attributes"=>{"1409570848547"=>{"title"=>"same properties", "_destroy"=>"false"}, "1409570857024"=>{"title"=>"same properties", "_destroy"=>"false"}}}, "commit"=>"Create Category"}
  User Load (0.5ms)  SELECT  "users".* FROM "users"  WHERE "users"."id" = 1  ORDER BY "users"."id" ASC LIMIT 1
   (0.4ms)  SELECT "categories"."id", "categories"."title" FROM "categories"
  CACHE (0.0ms)  SELECT "categories"."id", "categories"."title" FROM "categories"
   (0.2ms)  BEGIN
  Property Exists (0.4ms)  SELECT  1 AS one FROM "properties"  WHERE "properties"."title" = 'same properties' LIMIT 1
  CACHE (0.0ms)  SELECT  1 AS one FROM "properties"  WHERE "properties"."title" = 'same properties' LIMIT 1
  Category Exists (0.6ms)  SELECT  1 AS one FROM "categories"  WHERE "categories"."title" = 'Category' LIMIT 1
  SQL (0.5ms)  INSERT INTO "categories" ("created_at", "description", "icon", "order", "title", "updated_at") VALUES ($1, $2, $3, $4, $5, $6) RETURNING "id"  [["created_at", "2014-09-01 11:28:19.908849"], ["description", "category description"], ["icon", "http://4.bp.blogspot.com/-LOX6N2kXXaY/T5UtocrGRnI/AAAAAAAAAFU/EW_OZTHT1PI/s1600/1210167310_174374.jpg"], ["order", 12345], ["title", "Category"], ["updated_at", "2014-09-01 11:28:19.908849"]]
  SQL (0.3ms)  INSERT INTO "properties" ("created_at", "title", "updated_at") VALUES ($1, $2, $3) RETURNING "id"  [["created_at", "2014-09-01 11:28:19.910971"], ["title", "same properties"], ["updated_at", "2014-09-01 11:28:19.910971"]]
  SQL (0.4ms)  INSERT INTO "categories_properties" ("category_id", "created_at", "property_id", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "id"  [["category_id", 77], ["created_at", "2014-09-01 11:28:19.921763"], ["property_id", 90], ["updated_at", "2014-09-01 11:28:19.921763"]]
  SQL (0.4ms)  INSERT INTO "properties" ("created_at", "title", "updated_at") VALUES ($1, $2, $3) RETURNING "id"  [["created_at", "2014-09-01 11:28:19.947583"], ["title", "same properties"], ["updated_at", "2014-09-01 11:28:19.947583"]]
  SQL (0.4ms)  INSERT INTO "categories_properties" ("category_id", "created_at", "property_id", "updated_at") VALUES ($1, $2, $3, $4) RETURNING "id"  [["category_id", 77], ["created_at", "2014-09-01 11:28:19.950243"], ["property_id", 91], ["updated_at", "2014-09-01 11:28:19.950243"]]
   (0.5ms)  COMMIT
Redirected to http://0.0.0.0:3000/categories/77
Completed 302 Found in 129ms (ActiveRecord: 21.8ms)

  def properties_uniq? params
    properties = params.map{ |_,property| property[:title] }
    if properties.uniq.length < properties.length
      errors.add(:category, "Properties duplication are not allowed." ) 
      return false
    end
    true
  end 

  def create
    @category = Category.new(category_params)

    respond_to do |format|
      if @category.save && @category.properties_uniq?(params[:category][:properties_attributes])
        format.html { redirect_to @category, notice: 'Category was successfully created.' }
        format.json { render :show, status: :created, location: @category }
      else
        format.html { render :new }
        format.json { render json: @category.errors, status: :unprocessable_entity }
      end
    end
  end