ActiveAdmin侧栏没有显示任何记录

Question

我正在使用ActiveAdmin构建管理界面。所以我有文章和产品资源，在文章中显示我想制作一个侧边栏，看看分配给这篇文章的产品。补充工具栏看起来很好，但它不会显示任何记录。

---

Rails 4.1.0

ActiveAdmin 1.0.0

ruby​​ 2.1

---

应用/管理/ article.rb

ActiveAdmin.register Article, { :sort_order => :name_asc } do

    # Permitted parameters
    permit_params :title, :description

    # Displayed columns
    index do
        selectable_column
        column :title
        column :description
    default_actions
    end

    # Sidebar for Products by this Article
    sidebar 'Products by this Article', :only => :show do
        table_for Product.joins(:article).where(:article_id => article.id) do |s|
            s.column("Title") { |product| product.title }
        end
    end

    # Filters for title and description
    filter :title,         :as => :select               # :check_boxes (for checkboxes)
    filter :description,   :as => :select
end

应用/管理/ product.rb

ActiveAdmin.register Product, { :sort_order => :name_asc } do

    # Permitted parameters
    permit_params :article_id, :title, :description, :price

    # Displayed columns
    index do
        selectable_column
        column :article, :sortable => :article
        column :title
        column :description
    # Currency helper
        column :price, :sortable => :price do |cur|
            number_to_currency cur.price, locale: :ru
        end
        default_actions
    end

    # Filters for each column within "description"
    filter :article, :as => :select               # :check_boxes (for checkboxes)
    filter :title,   :as => :select
    filter :price
end

应用/模型/ article.rb

class Article < ActiveRecord::Base

    # Relationship
    has_many :products

    # Validations
    validates :title, :description, :presence => true
end

应用/管理/模型/ product.rb

class Product < ActiveRecord::Base

    # Relationship
    belongs_to :article

    # Validations
    validates :article, :title, :description, :price, :presence => true
end