无法检测保存嵌套对象时的错误

Question

我正在为嵌套表单使用 cocoon gem。 accommodation_category 可以有很多选项。我制作了一个表单结构，用户首先创建 accommodation_category 然后通过自定义控制器操作创建选项。

一切都按预期工作，但是嵌套的选项对象没有保存在我的数据库中。我将 cocoon 用于与 accommodation_category 相关的其他几个嵌套对象，但是选项对象是唯一不保存的对象。我检查了 2 天，但似乎无法在我的代码中找到 error/typo。

当运行在我的本地环境中到达我的 accommodation_category.rb 行 32

时我获得回滚

@accommodation_category = @accommodation_category.update_attributes(accommodation_category_params)

文本终端运行本地主机：

"Started PATCH "/parks/19/accommodation_categories/132" for ::1 at 2019-09-09 10:45:05 +0200

AccommodationCategoriesController 处理#update as HTML

参数：{"utf8"=>"✓", "authenticity_token"=>"X+BFZCfDrY2iGq+wH4H4c/XieKoVaLMUTZlNUaNb65OAxcm09fw2HyKkU2biQttzEsIzL87FIJFOFENpvc652Q==", "accommodation_category"=>{"options_attributes"=>{"1568018703588 "=>{"name"=>"1", "description"=>"", "_destroy"=>"false"}}}, "commit"=>"Save", "park_id"=>"19", "id"=>"132"}

用户负载（0.2 毫秒）SELECT "users".* FROM "users" WHERE "users"."id" = $1 ORDER BY "users" ."id" ASC 限制 $2 [["id", 2], ["LIMIT", 1]]

↳ /Users/xx/.rbenv/versions/2.5.3/lib/ruby/gems/2.5.0/gems/activerecord-5.2.3/lib/active_record/log_subscriber.rb:98 停放负载 (0.2ms) SELECT "parks".* FROM "parks" WHERE "parks"."id" = $1 LIMIT $2 [["id", 19] , ["LIMIT", 1]]

↳ app/controllers/accommodation_categories_controller.rb:29 AccommodationCategory Load (0.4ms) SELECT "accommodation_categories".* 从 "accommodation_categories" WHERE "accommodation_categories"."park_id" = $1 AND "accommodation_categories"."id" = $2 限额 $3 [["park_id", 19], ["id", 132], ["LIMIT", 1]]

↳ app/controllers/accommodation_categories_controller.rb:30 （0.2 毫秒）开始

↳ app/controllers/accommodation_categories_controller.rb:32 （0.1 毫秒）回滚

↳ app/controllers/accommodation_categories_controller.rb:32 AccommodationCategory Load (0.2ms) SELECT "accommodation_categories".* 从 "accommodation_categories" WHERE "accommodation_categories"."park_id" = $1 AND "accommodation_categories"."id" = $2 限额 $3 [["park_id", 19], ["id", 132], ["LIMIT", 1]]

↳app/controllers/accommodation_categories_controller.rb:44

重定向到 http://localhost:3000/accommodation_categories/132/new_discounts 在 19 毫秒内完成 302 发现（ActiveRecord：1.4 毫秒） “

结束文本终端运行本地主机

请在下面找到应用程序的代码：

accommodation_category.rb

class AccommodationCategory < ApplicationRecord
  belongs_to :park

  has_many :options, inverse_of: :accommodation_category, dependent: :destroy
  accepts_nested_attributes_for :options, allow_destroy: true, reject_if: ->(attrs) { attrs['name'].blank? }
end

option.rb

class Option < ApplicationRecord
  belongs_to :accommodation_category
end

accommodation_categories_controller.rb

class AccommodationCategoriesController < ApplicationController
[]
def new_options
    @accommodation_category = AccommodationCategory.find(params[:id])
    @park = @accommodation_category.park
    authorize @accommodation_category
  end

 def update
    @park = Park.find(params[:park_id])
    @accommodation_category = 
     @park.accommodation_categories.find(params[:id])
    authorize @accommodation_category
    @accommodation_category = 
  @accommodation_category.update_attributes(accommodation_category_params)
redirect_to root_path
end

private
  def accommodation_category_params
    params.require(:accommodation_category).permit(:name, :description, options_attributes: [:name, :description, :rank, _destroy])
  end
end

new_options.html.erb

<%= render 'options_new_form', park: @park%>

_option_new.html.erb

<%= simple_form_for [@park, @accommodation_category] do |f|%>
<% f.fields_for :options do |option| %>
  <%= render 'option_fields', f: option %>
<% end %>

<div>
  <%= link_to_add_association 'add option', f, :options %>
</div>

<%= f.submit "Save", class: "btn btn-primary" %>
<% end %>

_option_fields.html.erb

<div>
  <%= f.label :name %>
  <%= f.text_field :name %>

  <%= f.label :description %>
  <%= f.text_field :description %>

  <%= f.check_box :_destroy %>
  <%= link_to_remove_association "remove option", f %>
</div>

Answer 1

尝试添加 inverse_of

class AccommodationCategory < ApplicationRecord
  belongs_to :park

  has_many :options, dependent: :destroy, inverse_of: :accommodation_category
  accepts_nested_attributes_for :options, allow_destroy: true, reject_if: ->(attrs) { attrs['name'].blank? }
end

Answer 2

所以您的验证失败，导致 update_attributes 回滚。您的（显示的）控制器代码根本不处理任何错误，我希望是这样的：

 @accommodation_category.update_attributes(accommodation_category_params)
 if @accomodation.valid? 
   redirect_to root_path
 else
   render :edit
 end

此外，在呈现表单时，显示验证错误可能很有用。 Simple-form 将自动为您执行此操作（如果错误与显示的字段匹配）。否则你可以做类似

  = simple_form_for [@park, @accommodation_category] do |f|
    - if !@accomodation_category.valid?
      .alert.alert-error 
        Failed to save! Error:
        = @accomodation_category.errors.full_messages.join(", ")

（为了简洁明了，我使用 haml）

Answer 3

我发现了错误并且 @nathanvda 是正确的，参数不正确导致回滚。我虽然描述我如何使用 cocoon gem 找到嵌套表可能对其他人有用。

1) 我转到我的控制台并尝试创建一个带有选项的新 accommodation_category，这导致了回滚。

cat11=AccommodationCategory.create(name:'hello', options_attributes:[{name:'option 1'}])

2) 然后我检查它是否有效（显然不是）

cat11.valid?

3) 最后，我显示了错误信息

cat11.errors.full_messages
=> ["Park must exist", "Options age table must exist", "Options price must exist"]

我很确定我在调试 @nathanvda 时做错了，这应该给了我同样的错误信息。我通过链接价格和 age_table 来修复错误（我应该首先在我的问题中发布，但没有，因为我认为它不相关）。

无法检测保存嵌套对象时的错误

Unable to detect error in saving a nested object

postgresql

ruby-on-rails

rails-activerecord

cocoon-gem