Question

我在向购物车添加商品时遇到问题，而不是更新商品（如果已存在），则会创建重复商品。我知道我需要通过验证来检查order_item是否存在，但我不确定如何或在何处进行。

    class ApplicationController < ActionController::Base
  # Prevent CSRF attacks by raising an exception.
  # For APIs, you may want to use :null_session instead.
  protect_from_forgery with: :exception
  helper_method :current_order
  helper_method :current_buylist_order

  def current_order
    if !session[:order_id].nil?
      Order.find(session[:order_id])
    else
      Order.new
    end
  end
  end




class OrderItemsController < ApplicationController
  def create
    @order = current_order
    @order_item = @order.order_items.new(order_item_params)
    @order.save
    session[:order_id] = @order.id
  end

  def update
    @order = current_order
    @order_item = @order.order_items.find(params[:id])
    @order_item.update_attributes(order_item_params)
    @order_items = @order.order_items
  end

  def destroy
    @order = current_order
    @order_item = @order.order_items.find(params[:id])
    @order_item.destroy
    @order_items = @order.order_items
  end
private
  def order_item_params
    params.require(:order_item).permit(:quantity, :card_id)
  end
end

class CartsController < ApplicationController
  def show
    @order_items = current_order.order_items
  end
end

    class Order < ActiveRecord::Base
  belongs_to :order_status
  has_many :order_items
  before_create :set_order_status
  before_save :update_subtotal

  def subtotal
    order_items.collect { |oi| oi.valid? ? (oi.quantity * oi.unit_price) : 0 }.sum
  end

private

  def set_order_status
    self.order_status_id = 1
  end

  def update_subtotal
    self[:subtotal] = subtotal
  end 
end

class OrderItem < ActiveRecord::Base
  belongs_to :card
  belongs_to :order

  validates :quantity, presence: true, numericality: { only_integer: true, greater_than: 0 }
  validate :card_present
  validate :order_present

  before_save :finalize

  def unit_price
    if persisted?
      self[:unit_price]
    else
      card.price
    end
  end

  def total_price
    unit_price * quantity
  end

private
  def card_present
    if card.nil?
      errors.add(:card, "is not valid or is not active.")
    end
  end

  def order_present
    if order.nil?
      errors.add(:order, "is not a valid order.")
    end
  end

  def finalize
    self[:unit_price] = unit_price
    self[:total_price] = quantity * self[:unit_price]
  end
end

Answer 1

在您OrderItemsController中，在create和update方法中，您使用行@order_item = @order.order_items.new(order_item_params)，每次调用其中一个方法时，都会初始化新项。您需要更改这些方法，因此只有当具有相同参数的项目尚不存在时，它们才会创建新项目。请查看first_or_initialize或first_or_create方法。或者使用一个简单的条件（例如，如果订单中的商品增加数量为1，则创建新商品）

Answer 2

在订单项控制器中的create方法下，有一个代码检查现有产品，然后如果您多次添加到购物车中，则增加数量。您也可以使用jQuery禁用按钮。

在order_items_controller中的create方法下

require "active_record/connection_adapters/postgresql_adapter"

module ActiveRecord
 module ConnectionAdapters
   class PostgreSQLAdapter
     NATIVE_DATABASE_TYPES.merge!(
       timestamp: { name: "timestamptz" }
     )
   end
 end
end

添加和更新数量的额外方法

@product_id = params['order_item']['product_id']
@order.order_items.each do |oi|
  if oi.product_id.to_s == @product_id
      updater(oi.id,params['order_item']['quantity']) and return
  end
end

Answer 3

对我有用的是：

def create
    @order = current_order
   if OrderItem.where("card_id = ? AND order_id = ?", 
             params[:order_item][:card_id], @order.id.to_s).empty?
      @order_item = OrderItem.new(order_item_params)
      @order_item.order = current_order
      @order_item.save
   else
      @order_item = OrderItem.where("card_id = ? AND order_id = ?", 
             params[:order_item][:card_id], @order.id.to_s).first
      quantity = @order_item.quantity += params[:order_item][:quantity].to_i
      @order_item.update(quantity: quantity)
   end
end

增加车轨中的重复物品4

3 个答案: