Question

我正在开发电子商务应用程序，当用户将产品添加到购物车时，我无法弄清楚如何更新产品库存数量。因为我是一个新手，所以我遵循了大部分应用程序的教程。但是，当用户将产品添加到购物车时，本教程不会讨论如何更新产品库存数量。

到目前为止，我已将此方法添加到cart.rb模型

 def upd_quantity
  if cart.purchased_at
   product.decrement!(quantity: params[:stock_quantity])
  end
 end

但我真的被困住了，不知道我在做什么如果有人可以看看这个并告诉我如何将这个功能应用到应用程序，那将是很棒的。

这是指向github repo https://github.com/DadiHall/brainstore

的链接

这就是我现在所拥有的。

cart_item.rb型号

class CartItem
attr_reader :product_id, :quantity

  def initialize product_id, quantity = 1
    @product_id = product_id
    @quantity = quantity
  end

  def increment
    @quantity = @quantity + 1
  end

  def product
    Product.find product_id
  end

  def total_price
    product.price * quantity
  end

  def upd_quantity
   if cart.purchased_at
   product.decrement!(quantity: params[:stock_quantity])
  end
 end

end

cart.rb模型

class Cart
    attr_reader :items

    def self.build_from_hash hash
        items = if hash ["cart"] then 
            hash["cart"] ["items"].map do |item_data|
        CartItem.new item_data["product_id"], item_data["quantity"]
        end

    else
        []
    end

        new items
    end


  def initialize items = []
    @items = items
  end

  def add_item product_id
    item = @items.find { |item| item.product_id == product_id }
    if item
      item.increment
    else
      @items << CartItem.new(product_id)
    end
  end

  def empty?
    @items.empty?
  end

  def count
    @items.length
  end

  def serialize 
    items = @items.map do |item| 
        {
            "product_id" => item.product_id, 
            "quantity" => item.quantity
        }
    end

    {

            "items" => items
    }


  end

  def total_price
    @items.inject(0) { |sum, item| sum + item.total_price }
  end
end

product.rb型号

    class Product < ActiveRecord::Base

        mount_uploader :image, ImageUploader

        validates_presence_of :name, :price, :stock_quantity
        validates_numericality_of :price, :stock_quantity

        belongs_to :designer
        belongs_to :category
        belongs_to :page

        def self.search(query)

         where("name LIKE ? OR description LIKE ?", "%#{query}%", "%#{query}%") 
        end
    end


`cart_controller.rb`

class CartsController < ApplicationController
    before_filter :initialize_cart

    def add
        @cart.add_item params[:id]
        session["cart"] = @cart.serialize
        product = Product.find params[:id]
        redirect_to :back, notice: "Added #{product.name} to cart."
    end

    def show

    end

    def checkout
        @order_form = OrderForm.new user: User.new
        @client_token = Braintree::ClientToken.generate
    end

    def remove
  cart = session['cart']
  item = cart['items'].find { |item| item['product_id'] == params[:id] }
  if item
    cart['items'].delete item
  end
   redirect_to cart_path
  end


end

Answer 1

添加此行： product.update_columns(stock_quantity: product.stock_quantity - 1)

要在CartsController中添加操作吗？

def add
    @cart.add_item params[:id]
    session["cart"] = @cart.serialize
    product = Product.find params[:id]

    product.update_columns(stock_quantity: product.quantity - 1)

    redirect_to :back, notice: "Added #{product.name} to cart."
end

尝试将此产品从购物车中移除：

    def remove
        cart = session['cart']
        item = cart['items'].find { |item| item['product_id'] == params[:id] }

        product = Product.find(item['product_id'])
        product.update_columns(stock_quantity: product.stock_quantity + 1)

        if item
            cart['items'].delete item
        end
      redirect_to cart_path
    end

请注意，这仅适用于您一次添加和删除1个商品/产品的情况。我建议您在删除操作中将“item”重命名为“product”以保持一致性。

根据rails app中的购物车数量更新库存数量？

1 个答案: