Question

我实际上正在开发一个需要将练习链接到多个子类别的应用程序，子类别是父类别的子类。

这是我的代码：

Exercice.rb belongs_to：subcategory

class Exercice < ActiveRecord::Base
attr_accessible :title, :description, :subcategory_id

validates :title, :presence => true

has_many :programmeexercices
has_many :programmes, :through => :programmeexercices
belongs_to  :subcategory

end

category.rb has_many：exercices through：subcategories＆amp; has_many：子类别

class Category < ActiveRecord::Base
attr_accessible :name

has_many :exercices, :through => :subcategories
has_many :subcategories
end

subcategory.rb belongs_to：category＆amp; has_many：exercices

class Subcategory < ActiveRecord::Base
attr_accessible :name, :category_id

belongs_to :category
has_many :exercices
end

Exercices_controller

def new
    @exercice = Exercice.new
    @subcategories = Subcategory.all 
  end

  def edit
    @exercice = Exercice.find(params[:id])
    @subcategories = Subcategory.all
  end

  def create
    @exercice = Exercice.new(params[:exercice])
    params[:subcategories][:id].each do |subcategory|
      if !subcategory.empty?
        @exercice.subcategory.build(:subcategory_id => subcategory)
      end
  end

Category_controller

 def new
    @category = Category.new
  end

  def edit
    @category = Category.find(params[:id])
  end

 def create
    @category = Category.new(params[:category])
  end

Subcategory_controller

def new
    @subcategory = Subcategory.new
    @categories = Category.all
  end

def edit
    @subcategory = Subcategory.find(params[:id])
    @categories = Category.all
  end

  def create
    @subcategory = Subcategory.new(params[:subcategory])

    params[:categories][:id].each do |category|
      if !category.empty?
        @subcategory.category.build(:category_id => category)
      end
  end

练习_form视图我想：为练习分配子类别

      <li id="p-select">
        <% for subcategory in Subcategory.find(:all) %>
        <div class="row">
          <section class="twelve columns">
            <article class="valign row">
              <div>
                <label class="checkbox">
                   <%= check_box_tag "checkboxInput", subcategory.id, @exercice.subcategories.include?(subcategory) %>                                    
                </label> 
              </div>
               <div>
                <h3><%= exercice.title %></h3>
              </div>                       
          </article>
          <% end %>
          </section>
        </div>
      </li>
    </li>

子类别_形成视图我想：为子类别指定一个类别

<li class="field">
      <%= f.label :category %><br />
      <%= f.collection_select(:category_id, @categories, :id, :name, :include_blank => "Please select") %>
  </li>

无论表格是什么，我都收到错误消息：

=＆GT;子类别/新：

NoMethodError in Subcategories#new
undefined method `category_id' for #<Subcategory:0x4f676b8>

app/views/subcategories/_form.html.erb:16:in `block in _app_views_subcategories__form_html_erb___180268787_42055560'
app/views/subcategories/_form.html.erb:1:in `_app_views_subcategories__form_html_erb___180268787_42055560'
app/views/subcategories/new.html.erb:3:in `_app_views_subcategories_new_html_erb___1058729489_29352300'
app/controllers/subcategories_controller.rb:30:in `new'

=＆GT; exercice / new：

NoMethodError in Exercices#new
undefined method `subcategories' for #<Exercice:0x4c992c0>

  app/views/exercices/_form.html.erb:31:in `block (2 levels) in _app_views_exercices__form_html_erb__725096104_41604048'
app/views/exercices/_form.html.erb:25:in `each'
 app/views/exercices/_form.html.erb:25:in `block in _app_views_exercices__form_html_erb__725096104_41604048'
 app/views/exercices/_form.html.erb:2:in `_app_views_exercices__form_html_erb__725096104_41604048'
 app/views/exercices/new.html.erb:3:in `_app_views_exercices_new_html_erb___924742088_42063192'
 app/controllers/exercices_controller.rb:31:in `new'

谁知道我哪里错了？谢谢:)）

Answer 1

老实说，我认为你需要回去修改很多代码。

您的表单中有exercices.subcategories来电，导致您的第二次错误，因为Exercise belongs_to :subcategory因此每次练习只能有一个子类别。

您循环遍历所有子类别，为练习表单上的每个子类别提供一个复选框，表示您实际上希望练习具有多个子类别。

您已将复选框的税号命名为checkBoxInput，然后您希望控制器中有参数subcategories[]。

您还要输出每个子类别的练习题。

因此，在尝试修复特定错误之前，我会向后退几步并整理代码的大部分逻辑。

Answer 2

好的，我明白了！

我想要的是：练习有多个子类别，只有一个类别。子类别只有一个类别。一个类别有多个子类别。

****class Exercice < ActiveRecord::Base****
  attr_accessible :title, :subcategory_id

  has_many :subcategories
  has_one :category, :through => :subcategories


****class Category < ActiveRecord::Base*****
  attr_accessible :name

  has_many :subcategories
  has_many :exercices, :through => :subcategories


***class Subcategory < ActiveRecord::Base****
  attr_accessible :name, :category_id

  belongs_to :category
  has_many :exercices

那是对的吗？

Rails 3.2类别＆amp;子目录

2 个答案: