多态关联未定义方法`build_product' [英] Polymorphic association undefined method `build_product'

问题描述

我很难看出我在这里做错了什么..

I am struggling to see what I am doing wrong here..

我有一个订单模型，需要能够容纳一个产品，该产品需要是多态的.

I have an order model which needs to be able to hold one product, the product needs to be polymorphic.

我有一个名为 orthosis_specification 的产品/模型，出于某种原因，当我在 fields_for 创建中使用它时出现此错误.

I have a product/model called orthosis_specification and for some reason I am getting this error when I use it in a fields_for creation.

迁移 -

class CreateOrders < ActiveRecord::Migration
  def change
    create_table :orders do |t|
      t.datetime :order_date
      t.datetime :date_required
      t.boolean :correct
      t.references :user, index: true, foreign_key: true
      t.references :practitioner, index: true, foreign_key: true
      t.references :product, polymorphic: true
      t.references :shipping_address, index: true, foreign_key: true
      t.references :invoice_address, index: true, foreign_key: true
      t.timestamps null: false
    end
  end
end

订单控制器 -

  def new
    @order = Order.new
    @order.build_patient
    @order.build_product #Also tried: @order.build_orthosis_specification
  end

订单模型 -

class Order < ActiveRecord::Base
  has_one :patient
  belongs_to :product, polymorphic: true
  accepts_nested_attributes_for :patient,
                                reject_if: proc { |attributes| attributes['first_name'].blank? },
                                allow_destroy: true
  accepts_nested_attributes_for :product,
                                reject_if: proc { |attributes| attributes['transfer_name'].blank? },
                                allow_destroy: true

  def to_s
    name
  end
end

矫形器规格模型 -

class OrthosisSpecification < ActiveRecord::Base
    has_one :order, :as => :product, class_name: 'Order'
end

订单视图 -

  <%= form_for(@order) do |f| %>
  <% if @order.errors.any? %>
  <% end %>

<%= f.fields_for :orthosis_specification do |fa| %>

实际错误信息 -

undefined method `build_orthosis_specification' for #<Order:0x007f8950e29970>

矫形器规范迁移 -

class CreateOrthosisSpecifications < ActiveRecord::Migration
  def change
    create_table :orthosis_specifications do |t|
      t.string :transfer_name
      t.string :modifications
      t.string :primary_mods
      t.string :top_opening
      t.string :side_opening
      t.string :chape_position
      t.string :scan_file
    end
  end
end

任何帮助将不胜感激，谢谢！

Any help would be massively appreciated, thanks!

推荐答案

多态关联不会生成 build_xxx 方法.只有当您知道要创建的产品类型时，您才能创建新产品:

Polymorphic associations don't generate the build_xxx methods. You can create a new product only if you know what kind of product you want to create :

#Creating a new OrthosisSpecification product associated with @order :
@order.product = OrthosisSpecification.new

文档:http://api.rubyonrails.org/classes/ActiveRecord/关联/ClassMethods.html

这篇关于多态关联未定义方法`build_product'的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！