将购物车分配给用户

Question

我正在尝试构建一个分配给用户的购物车。现在发生的情况是，当一个项目被添加到购物车时，它是为每个用户添加的。似乎每个用户都在使用同一个购物车，我无法让用户添加到其他用户的购物车。我怎样才能让每个用户都有一个独特的购物车并且只能添加到他们的购物车中？

这是我所拥有的：

class CartsController < ApplicationController
  before_action :set_cart, only: [:show, :edit, :update, :destroy]
  before_action :logged_in_user, only: [:create, :edit, :update, :destroy, :show]
  rescue_from ActiveRecord::RecordNotFound, with: :invalid_cart

  # GET /carts
  # GET /carts.json
  def index
    @carts = Cart.all
  end

  # GET /carts/1
  # GET /carts/1.json
  def show
  end

  # GET /carts/new
  def new
    @cart = Cart.new
  end

  # GET /carts/1/edit
  def edit
  end

  # POST /carts
  # POST /carts.json
  def create
    @cart = Cart.new(cart_params)
    respond_to do |format|
      if @cart.save
        format.html { redirect_to @cart, notice: 'Cart was successfully created.' }
        format.json { render action: 'show', status: :created, location: @cart }
      else
        format.html { render action: 'new' }
        format.json { render json: @cart.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /carts/1
  # PATCH/PUT /carts/1.json
  def update
    respond_to do |format|
      if @cart.update(cart_params)
        format.html { redirect_to @cart, notice: 'Cart was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: 'edit' }
        format.json { render json: @cart.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /carts/1
  # DELETE /carts/1.json
  def destroy
    @cart.destroy if @cart.id == session[:cart_id]
    session[:cart_id] = nil
    respond_to do |format|
      format.html { redirect_to store_url, notice: "Your cart is currently empty" }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_cart
      @cart = Cart.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def cart_params
      params[:cart]
    end

    def invalid_cart
      logger.error "Attempt to access invalid cart #{params[:id]}"
      redirect_to store_url, notice: "Invalid Cart"
    end
end

current_cart.rb

module CurrentCart
  extend ActiveSupport::Concern

  private
    def set_cart
      @cart = Cart.find(session[:cart_id])
      rescue ActiveRecord::RecordNotFound
        @cart = Cart.create
        session[:cart_id] = @cart.id
    end
end

line_item_controller.rb

class LineItemsController < ApplicationController
  include CurrentCart
  before_action :set_cart, only: [:new, :create]
  before_action :set_line_item, only: [:show, :edit, :update, :destroy]


  # GET /line_items
  # GET /line_items.json
  def index
    @line_items = LineItem.all
  end

  # GET /line_items/1
  # GET /line_items/1.json
  def show
  end

  # GET /line_items/new
  def new
    @line_item = LineItem.new
  end

  # GET /line_items/1/edit
  def edit
  end

  # POST /line_items
  # POST /line_items.json
  def create
    product = Product.find(params[:product_id])
    @line_item = @cart.add_product(product: product)
    respond_to do |format|
      if @line_item.save
        format.html { redirect_to @line_item.cart, notice: 'Line item was successfully created.' }
        format.json { render action: 'show', status: :created, location: @line_item }
      else
        format.html { render action: 'new' }
        format.json { render json: @line_item.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /line_items/1
  # PATCH/PUT /line_items/1.json
  def update
    respond_to do |format|
      if @line_item.update(line_item_params)
        format.html { redirect_to @line_item.cart, notice: 'Line item was successfully updated.' }
        format.json { head :no_content }
      else
        format.html { render action: 'edit' }
        format.json { render json: @line_item.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /line_items/1
  # DELETE /line_items/1.json
  def destroy
    @line_item.destroy
    respond_to do |format|
      format.html { redirect_to line_items_url }
      format.json { head :no_content }
    end
  end

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_line_item
      @line_item = LineItem.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def line_item_params
      params.require(:line_item).permit(:product_id )
    end
end

Answer 1

您应该执行以下操作，而不是 CurrentCart.rb 中的 Cart.create 和 Cart.find：

def set_cart
  @cart = current_user.carts.find_by(id: session[:cart_id]) || current_user.carts.create
  session[:cart_id] = @cart.id
end

find_by 如果找不到它不会抛出错误；它只是返回 nil，所以你不必担心救援。