如何仅使用simple_form显示其父产品的product_variant？

如何解决如何仅使用simple_form显示其父产品的product_variant？

问题是我只希望与此显示页面下拉列表中显示的product_id关联的product_variant。取而代之的是，在下拉列表中，我看到了已在数据库中输入的所有product_variant，而不仅仅是针对产品的那些。

您将如何指定此simple_form product_variants仅应用于@product？

在产品展示页面中

<%= simple_form_for [@product_variant,@order_item] do |f| %>
  <%= f.input :quantity %>
  <%= f.association :product_variant,label_method: :name_of_method %>

  <%= f.button :submit,"Add to cart" %>
<% end %>

当前，用户可以在每个产品的展示页面上选择一个product_variant并将其成功添加到购物车中。

这是我的模特：

OrderItem

  belongs_to :order,optional: true
  belongs_to :cart,optional: true
  belongs_to :product_variant

  accepts_nested_attributes_for :product_variant

ProductVariant

  belongs_to :product
  has_many :order_items

  validates :item,presence: true


  def name_of_method
  "#{item} / #{color} / #{size} / $#{price_in_dollars}"
  end

  def price_in_dollars
   price / 100
 end

Product

  has_many :product_variants,:dependent => :destroy

  has_many :order_items

Cart

  has_many :order_items

＆这是我的路线

  # we want to see multiple products
  resources :products

    resources :product_variants do
      resources :order_items
    end


  resources :selected_variants

  # we want a user to only have one cart
  resource :cart

   # we want our users to order multiple times
  resources :orders

  root "products#index"

这是我的产品控制器，其中def show中有product_variant显示的代码：

class ProductsController < ApplicationController

  def index
    @products = Product.all
  end

  def new
    @product = Product.new
  end

  def create
    @product = Product.new(product_params)
    @product.save
  end

  def show

    @product = Product.friendly.find(params[:id])
    @product_variant = ProductVariant.find_by(params[:product_variant_id])

    # if the product is already in the cart
 @order_item = @current_cart.order_items.find_by(product_variant: @product_variant)

   if @order_item.nil?
     # if it doesn't exist in the cart
     @order_item = @current_cart.order_items.new(product_variant: @product_variant,quantity: 1)
   end

  end

  def edit
  end

  def update
    render "edit"
  end

  def destroy
  end



  def product_params
    Params.require(:product).permit(:title,:description,:price,:cover_image,:image_1,:image_2,:image_3 )
  end



end

这是我相关表格的架构：

  create_table "product_variants",force: :cascade do |t|
    t.string "item"
    t.string "size"
    t.string "color"
    t.integer "price"
    t.integer "product_id",null: false
    t.datetime "created_at",precision: 6,null: false
    t.datetime "updated_at",null: false
    t.index ["product_id"],name: "index_product_variants_on_product_id"
  end

  create_table "products",force: :cascade do |t|
    t.string "title"
    t.string "cover_image"
    t.text "description"
    t.integer "price"
    t.string "image_1"
    t.string "image_2"
    t.string "image_3"
    t.boolean "is_sold_out",default: false
    t.datetime "created_at",null: false
    t.string "slug"
    t.index ["slug"],name: "index_products_on_slug",unique: true
  end

  create_table "order_items",force: :cascade do |t|
    t.integer "cart_id"
    t.integer "product_id"
    t.integer "product_variant_id"
    t.integer "order_id"
    t.integer "quantity"
    t.datetime "created_at",null: false
    t.index ["cart_id"],name: "index_order_items_on_cart_id"
    t.index ["order_id"],name: "index_order_items_on_order_id"
    t.index ["product_id"],name: "index_order_items_on_product_id"
    t.index ["product_variant_id"],name: "index_order_items_on_product_variant_id"
  end

我很乐意提供您认为与解决此问题相关的任何其他代码。

亚伦