Question

我的目标是使用相同的表单创建新的Order和关联的OrderItem。

模型

class Order < ActiveRecord::Base
  belongs_to :user
  has_many :order_items, dependent: :destroy
  accepts_nested_attributes_for :order_items
  validates_associated :order_items
end

class OrderItem < ActiveRecord::Base
  belongs_to :order
  default_scope -> { order(created_at: :desc) }
end

查看

<% @items.each do |item| %>
  <%= form_for(@order) do |f| %>
    <%= f.hidden_field :user_id, :value => session[:user_id] %>
    <%= f.fields_for :order_items do |oi| %>
      <%= oi.hidden_field :product_id, :value => item.id %>
      <%= oi.hidden_field :price, :value => item.price %>
      <%= oi.number_field :quantity, value: 1, class: 'form-control',     min: 1 %>
    <% end %>  
    <%= f.submit "Buy Now", class: "btn btn-primary" %>
  <% end %>

控制器

def new
  @order = Order.new
  @order.order_items.build
end

def create
  @order = Order.new(order_params)

  if @order.save 
    redirect_to cart_path
  else
    redirect_to root_url
  end
end

private
  def order_params
    params.require(:order).permit(:user_id, :custom_item_id, order_items_attributes: [:product_id, :price, :quantity])
  end

将嵌套表单数据提交到数据库时，会返回错误消息Unpermitted parameter: order_item，并且只保存order数据。

更新＆lt; - 已解决此问题

当我删除“f。”来自<%= f.fields_for的表单正确呈现，order_params包含order_items数据。这很有趣，因为表单助手的RailsGuide包含“f”。 http://guides.rubyonrails.org/form_helpers.html#nested-forms

参数

{"utf8"=>"✓", "authenticity_token"=>"<TOKEN>", "order"=>{"user_id"=>"1", "order_item"=>{"product_id"=>"5", "price"=>"120.0", "quantity"=>"1"}}, "commit"=>"Buy Now"}

数据仍然无法保存到相应的型号中。

更新2 ＆lt; - 已解决此问题

将控制器中的create操作更新为if @order.save!，以下是错误消息：

Validation failed: Order items order can't be blank, Order items product can't be blank, Order items quantity can't be blank, Order items price can't be blank, Order items is invalid

我认为错误出现在这行代码@order.order_items.build(order_params[:order_items_attributes])中，但我不确定我需要改变什么。

更新3 Unpermitted parameter: order_item错误消息

从终端： Processing by OrdersController#create as HTML Parameters: {"utf8"=>"✓", "authenticity_token"=><TOKEN>, "order"=> "user_id"=>"1", "order_item"=>{"product_id"=>"5", "price"=>"120.0", quantity"=>"1"}}, "commit"=>"Buy Now"} User Load (0.5ms) SELECT "users".* FROM "users" WHERE "users"."id" = ? LIMIT 1 [["id", 1]] Unpermitted parameter: order_item (0.2ms) begin transaction SQL (1.4ms) INSERT INTO "orders" ("user_id", "created_at", "updated_at") VALUES (?, ?, ?) [["user_id", 1], ["created_at", "2016-03-18 14:58:21.724246"], ["updated_at", "2016-03-18 14:58:21.724246"]] (14.4ms) commit transaction order_items数据未保存。

Answer 1

首先，在OrderItem中，您的关联似乎不正确。它应该是belongs_to :order而不是belongs_to :order_item_params。

其次，我认为您的表单应该说<%= f.fields_for :order_items do |oi| %>（:order_items而非:order_item）

最后，您不需要在控制器中执行此操作：@order.order_items.build(order_params[:order_items_attributes])

控制器

def create
  @order = Order.new(order_params)
  if @order.save 
    redirect_to cart_path
  else
    redirect_to root#url
  end
end

def order_params
    params.require(:order).permit(:user_id, :custom_item_id, order_items_attributes: [:product_id, :price, :quantity])
end

Answer 2

呈现表单的视图不在另一个控制器中，而不在orders控制器中。视图的show操作不包含order_items的实例变量。这导致了错误消息。谢谢你的帮助。对于寻找嵌套表单资源的人来说，下面是一些有用的资源。

YouTube Video Instructions

API dock for fields_for

Go Rails video for Form Nested Attributes and Fields For in Rails

Active Record Nested Attributes

Rails Guide: Active Record Associations

Rails 4嵌套表单，错误：未允许的参数：order_item

2 个答案:

控制器