ruby-on-rails - 购物车，可以使用 Devise 的 session 功能吗？

Question

我正在编写一个电子商务网站，我需要实现购物车功能。我希望客户无需事先注册就可以将产品添加到他们的购物车中，所以我想我可以通过 session 来实现这一点。

这可以在 Devise gem 中完成还是我必须实现我自己的 session 模型才能使其工作？

Answer 1

您需要处理自己的 session 数据 - 并不意味着您需要 session model尽管。
我们已经实现了你正在寻找的东西。它使用 session 模型工作，但使用我为您推荐的相同基本功能:

#app/models/cart_session.rb
class CartSession

    #Initalize Cart Session
    def initialize(session)
        @session = session
        @session[:cart] ||= {}
    end

    #Cart Count
    def cart_count
        if (@session[:cart][:products] && @session[:cart][:products] != {})
            @session[:cart][:products].count
        else
            0
        end
    end

    #Cart Contents
    def cart_contents
        products = @session[:cart][:products]

        if (products && products != {})

            #Determine Quantities
            quantities = Hash[products.uniq.map {|i| [i, products.count(i)]}]

            #Get products from DB
            products_array = Product.find(products.uniq)

            #Create Qty Array
            products_new = {}
            products_array.each{
                |a| products_new[a] = {"qty" => quantities[a.id.to_s]}
            }

            #Output appended
            return products_new

        end

    end

    #Qty & Price Count
    def subtotal
        products = cart_contents

        #Get subtotal of the cart items
        subtotal = 0
        unless products.blank?
            products.each do |a|
                subtotal += (a[0]["price"].to_f * a[1]["qty"].to_f)
            end
        end

        return subtotal

    end

    #Build Hash For ActiveMerchant
    def build_order

        #Take cart objects & add them to items hash
        products = cart_contents

        @order = []
        products.each do |product|
            @order << {name: product[0].name, quantity: product[1]["qty"], amount: (product[0].price * 100).to_i }
        end

        return @order
    end

    #Build JSON Requests
    def build_json
        session = @session[:cart][:products]
        json = {:subtotal => self.subtotal.to_f.round(2), :qty => self.cart_count, :items => Hash[session.uniq.map {|i| [i, session.count(i)]}]}
        return json
    end

  
end

session
根据 Rails documentation :

Most applications need to keep track of certain state of a particularuser. This could be the contents of a shopping basket or the user idof the currently logged in user. Without the idea of sessions, theuser would have to identify, and probably authenticate, on everyrequest. Rails will create a new session automatically if a new useraccesses the application. It will load an existing session if the userhas already used the application.

据我所知， session 是为每个用户存储数据的小型 cookie 文件。这些是不明确的(为每个用户创建 - 无论他们是否登录)，这意味着我会将它们用于您的购物车
我们使用 Sessions通过存储原始数据来创建购物车数据 id session 中购物车产品的

设计
关于设计的说明 - 您要问的与设计 gem 无关。 Devise 是一个身份验证系统，这意味着它会处理用户是否有权访问您的应用程序；它不处理购物车数据
虽然 Devise 将数据存储在 sessions ，您需要定义自己的 session您购物车的数据。我们使用 cart 来做到这一点具有上述型号代码的 Controller :

#config/routes.rb
get 'cart' => 'cart#index', :as => 'cart_index'
post 'cart/add/:id' => 'cart#add', :as => 'cart_add'
delete 'cart/remove(/:id(/:all))' => 'cart#delete', :as => 'cart_delete'

#app/controllers/cart_controller.rb
class CartController < ApplicationController
    include ApplicationHelper

    #Index
    def index
        @items = cart_session.cart_contents
        @shipping = Shipping.all
    end

    #Add
    def add
        session[:cart] ||={}
        products = session[:cart][:products]

        #If exists, add new, else create new variable
        if (products && products != {})
            session[:cart][:products] << params[:id]
        else
            session[:cart][:products] = Array(params[:id])
        end

        #Handle the request
        respond_to do |format|
            format.json { render json: cart_session.build_json }
            format.html { redirect_to cart_index_path }
        end
    end

    #Delete
    def delete
        session[:cart] ||={}
        products = session[:cart][:products]
        id = params[:id]
        all = params[:all]

        #Is ID present?
        unless id.blank?
            unless all.blank?
                products.delete(params['id'])
            else
                products.delete_at(products.index(id) || products.length)
            end
        else
            products.delete
        end

        #Handle the request
        respond_to do |format|
            format.json { render json: cart_session.build_json }
            format.html { redirect_to cart_index_path }
        end
    end

end