将商品添加到购物车

Question

我需要团队项目的帮助。我的任务是“添加到购物车”功能。我被困住了。我需要在产品页面上的每个项目旁边添加一个按钮，单击该按钮时，它会添加该项目并将用户定向到购物车页面。下面我添加了代码以提供更好的理解。

//小车控制器

class CartController < ApplicationController
  def index
    @cart = Prebuilt.all
    render :index
  end

  def show
    @cart = current_cart
   end

  def add_to_cart
    current_cart.add_item(params[:prebuilt_id])
  end

end

//购物车模型

class Cart < ApplicationRecord
  has_many :items

  def add_item(prebuilt_id)
    item = items.where('prebuilt_id', prebuilt_id.first)
    save
  end

end

//商品型号

class Item < ApplicationRecord
  belongs_to :cart
end

//路线

# root to: redirect('/cart')

  get 'cart', to: 'cart#index', as: 'cart';

  post '/add_to_cart/:prebuilt_id' => 'cart#add_to_cart', :as => 'add_to_cart'

  get 'checkout', to: 'pages#checkout', as: 'checkout';

  get 'confirm', to: 'pages#confirm', as: 'confirm';

// 种子.rb

prebuilt1 = Prebuilt.create!(
  name: "Alfred's Artistic Jet",
  description: "Designed by Alfred",
  manufacturer: "Boeing",
  color: "Mixed",
  size: "Large",
  price: 2999999
)

prebuilt2 = Prebuilt.create!(
  name: "Brittany's Barbie Jet",
  description: "Designed by Brittany",
  manufacturer: "Boeing",
  color: "Pink",
  size: "Large",
  price: 4499999
)

prebuilt3 = Prebuilt.create!(
  name: "Peter's Prehistoric Jet",
  description: "Designed by Peter",
  manufacturer: "Airbus",
  color: "Blue",
  size: "Small",
  price: 7999999
)

prebuilt4 = Prebuilt.create!(
  name: "Tianna's Tractor-Themed Jet",
  description: "Designed by Tianna",
  manufacturer: "Airbus",
  color: "Mixed",
  size: "Large",
  price: 1999999
)

// 产品页面

<table class="table table-striped table-hover">

  <thead class="table-dark">
    <tr>
      <th>Name</th>
      <th>Description</th>
      <th>Manufacturer</th>
      <th>Color</th>
      <th>Size</th>
      <th>Price</th>
      <th></th>
    </tr>
  </thead>

  <tbody>
    <% @prebuilts.each do |prebuilt| %>
      <tr>
        <td><%= prebuilt.name %></td>
        <td><%= prebuilt.description %></td>
        <td><%= prebuilt.description %></td>
        <td><%= prebuilt.manufacturer %></td>
        <td><%= prebuilt.color %></td>
        <td><%= prebuilt.size %></td>
        <td><%= prebuilt.price %></td>
        <td class="text-nowrap">
          <%= link_to 'show', prebuilt_path(prebuilt), class: 'btn btn-sm btn-outline-secondary' %>
          <td><%= button_to "add to cart", cart_path(:prebuilt_id => prebuilt), method: :post %></td>
        </td>
      </tr>
    <% end %>
  </tbody>

</table>

// 购物车页面

<table id="line_items">
  <tr>
    <th>Product</th>
    <th>Qty</th>
    <th class="price">Unit Price</th>
    <th class="price">Full Price</th>
  </tr>

  <% for item in @cart %>
    <tr class="<%= cycle :odd, :even %>
       <td><%=h item.name %></td>
    </tr>
   <% end %>
  </tr>
</table>

Answer 1

class CartController < ApplicationController
  def add_to_cart
    current_cart.add_item(params[:prebuilt_id])
    redirect_to cart_path(current_cart.id)
  end
end

项目可能也应该属于 Prebuild

class Item < ApplicationRecord
  belongs_to :cart
  belongs_to :prebuild
end

添加项目就像搜索现有项目并更新它或创建新项目

class Cart < ApplicationRecord
  has_many :items

  def add_item(prebuilt_id)
    item = items.find_by(prebuilt_id: prebuilt_id)
    if item
      item.update(count: item.count + 1)
    else
      items.create(prebuilt_id: prebuilt_id, count: 1)
    end
  end
end

或者如果你没有计数并且每个位置可以只有 1

  def add_item(prebuilt_id)
    items.find_or_create_by(prebuilt_id: prebuilt_id)
  end