Refactor stock feature

app/controllers/carts_controller.rb

 class CartsController < ApplicationController
   include CartsHelper
 
-  before_action :set_cart
-  before_action :set_item, only: [:add_line_item, :update_line_item, :remove_line_item]
-  before_action -> { render_warning_notice('Please specify quantity') },
-                if: :quantity_equal_zero?, only: :add_line_item
-  before_action -> { render_warning_notice('Product is out of stock') },
-                unless: :product_is_out_of_stock?,
-                only: [:add_line_item, :update_line_item]
+  before_action :set_product_item,
+                only: [:add_product_item, :update_product_item, :remove_product_item]
+  before_action :build_empty_quantity_notice, if: :quantity_equal_zero?,
+                only: :add_product_item
   rescue_from ActiveRecord::RecordNotFound, with: :invalid_cart
 
   # GET /cart
   def index
-    @line_items = @cart.get_all_items
+    @product_items = @cart.product_items
   end
 
   # POST /cart/add/1
-  def add_line_item
-    @cart.add(*cart_params.to_h.values)
-
-    respond_to do |format|
-      notice_msg =  { msg: "#{@item.title} was sucessfully added to your cart",
+  def add_product_item
+    if @cart.add_product_item(params[:product_id], params[:product_quantity])
+      respond_to do |format|
+        format.js do
+          @notice = { msg: "#{@product_item.title} was sucessfully added to your cart",
                       type: :success }
-      format.html { redirect_to cart_index_url, notice: notice_msg[:msg] }
-      format.js { @notice = { msg: notice_msg[:msg], type: notice_msg[:type] } }
+        end
+      end
+    else
+      render_warning_notice('Product is out of stock')
     end
+
   end
 
   # PUT/PATCH /cart/update/1
-  def update_line_item
-    @cart.update(*cart_params.to_h.values)
-
-    respond_to do |format|
-      notice_msg = { msg: "#{@item.title} was sucessfully updated",
-                     type: :success }
-
-      format.html { redirect_to cart_index_url, notice: notice_msg[:msg] }
-      format.js { @notice = { msg: notice_msg[:msg], type: notice_msg[:type] }}
+  def update_product_item
+    if @cart.update_product_item(params[:product_id],
+                                 params[:product_quantity])
+      redirect_to cart_index_url, notice: "#{@product_item.title} was sucessfully updated"
+    else
+      redirect_to cart_index_url, notice: "Can not update #{@product_item.title}"
     end
   end
 
   # DELETE /cart/1
-  def remove_line_item
-    @cart.remove_item(params[:id])
-
-    respond_to do |format|
-      notice_msg = "#{@item.title} was sucessfully removed from your cart"
-      format.html { redirect_to cart_index_url, notice: notice_msg }
+  def remove_product_item
+    if @cart.remove_product_item(params[:product_id])
+      redirect_to cart_index_url, notice: "#{@product_item.title} was sucessfully removed from your cart"
+    else
+      redirect_to cart_index_url, notice: "#{@product_item.title} can not remove from your cart"
     end
   end
 
   # DELETE /cart/remove
   def destroy
     destroy_cart_session
-
-    respond_to do |format|
-      format.html { redirect_to root_url }
-    end
+    redirect_to root_url, notice: 'Your cart is empty'
   end
 
   private
 
-  def cart_params
-    params.permit(:id, :product_quantity)
-  end
-
   def invalid_cart
     destroy_cart_session
     redirect_to root_url
   end
 
-  def set_item
-    @item = Product.find(params[:id])
+  def set_product_item
+    @product_item = Product.find(params[:product_id])
   end
 
   def quantity_equal_zero?
     params[:product_quantity].to_i.zero?
   end
 
-  def product_is_out_of_stock?
-    if action_name == 'add_line_item'
-      input_quantity = @cart.get_item_quantity(*cart_params.to_h.values)
-    else
-      input_quantity = params[:product_quantity]
-    end
-    Product.find(params[:id]).is_in_stock?(input_quantity)
+  def build_empty_quantity_notice
+    render_warning_notice('Please specify quantity')
   end
 
   def render_warning_notice(notice)

app/controllers/orders_controller.rb

@@ -2,8 +2,7 @@ class OrdersController < ApplicationController
   include CartsHelper
 
   before_action :authenticate_user!, only: :new
-  before_action :set_cart, only: [:new, :create]
-  before_action :set_line_items, only: :new
+  before_action :set_order_items, only: :new
 
   # GET /orders/new
   def new
@@ -13,27 +12,28 @@ class OrdersController < ApplicationController
 
   # POST /orders
   def create
-    @order = current_user.orders.create!
-    create_line_items_for_order(@order)
+    @order = Order.create(user: current_user)
+    save_order_items(@order)
 
-    respond_to do |format|
+    if @order.present?
       destroy_cart_session
       OrderMailer.send_order_detail_to_user(current_user, @order).deliver_later
-      format.html { redirect_to root_url, notice: 'Your order is successfully created' }
+      redirect_to root_url, notice: 'Your order is successfully created'
+    else
+      redirect_to root_url, notice: 'Your order can not be created'
     end
-  rescue ActiveRecord::RecordNotSaved
-    redirect_to root_url, notice: 'Your order can not be created'
   end
 
-  def create_line_items_for_order(order)
-    @cart.get_all_items.each do |_, attrs|
-      order.line_items.create(product: attrs[:product], quantity: attrs[:quantity])
+  def save_order_items(order)
+    @cart.product_items.values.each do |attrs|
+      order.product_items.create(product: attrs[:product],
+                                 quantity: attrs[:quantity])
     end
   end
 
   private
 
-  def set_line_items
-    @line_items = @cart.get_all_items
+  def set_order_items
+    @order_items = @cart.product_items
   end
 end
\ No newline at end of file

app/helpers/carts_helper.rb

 module CartsHelper
   def set_cart
     session[:cart] ||= {}
-    @cart = Cart.new(session[:cart])
+    @cart ||= Cart.new(Product, session[:cart])
   end
 
   def destroy_cart_session

app/models/order.rb

 class Order < ApplicationRecord
-  has_many :line_items, dependent: :destroy
+  has_many :product_items, dependent: :destroy
   belongs_to :user
 
   def total_price
-    line_items.to_a.sum { |item| item.product.price * item.quantity }
+    product_items.to_a.sum { |item| item.product.price * item.quantity }
   end
 end
\ No newline at end of file

app/models/product.rb

@@ -7,7 +7,7 @@ class Product < ApplicationRecord
   validates :category_id, presence: true
   validates :user_id, presence: true
 
-  def is_in_stock?(required_quantity)
+  def in_stock?(required_quantity)
     quantity >= required_quantity.to_i
   end
 

app/models/line_item.rb → app/models/product_item.rb

-class LineItem < ApplicationRecord
+class ProductItem < ApplicationRecord
   belongs_to :product, optional: true
   belongs_to :order, optional: true
   after_create :update_product_quantity

app/services/cart.rb

 class Cart
-  def initialize(cart_session = {})
+  def initialize(product, cart_session = {})
     @cart = cart_session
+    @product = product
   end
 
-  def add(id, quantity)
-    return if quantity.to_i.zero?
-    if @cart.key?(id.to_s)
-      @cart[id.to_s][:quantity.to_s] += quantity.to_i
+  def product_items
+    product_items = {}
+    @cart.each do |id, attrs|
+      product_items[id] = { product: @product.find(id),
+                            quantity: attrs[:quantity.to_s].to_i }
+    end
+    product_items
+  end
+
+  def add_product_item(product_id, quantity)
+    real_quantity = product_quantity(product_id, quantity)
+    return false unless product_is_in_stock?(product_id, real_quantity)
+    if product_item_exist?(product_id)
+      @cart[product_id.to_s][:quantity.to_s] += real_quantity.to_i
     else
-      @cart[id.to_s] = { quantity: quantity.to_i }
+      @cart[product_id.to_s] = { quantity: real_quantity.to_i }
     end
   end
 
-  def update(id, quantity)
-    return unless @cart.key?(id)
+  def update_product_item(product_id, quantity)
+    return false unless can_update_product_item?(product_id, quantity)
     if quantity.to_i.zero?
-      remove_item(id)
+      remove_product_item(product_id)
     else
-      @cart[id][:quantity.to_s] = quantity.to_i
+      @cart[product_id][:quantity.to_s] = quantity.to_i
     end
   end
 
-  def get_item_quantity(id, new_quantity = 0)
-    return new_quantity.to_i if @cart.empty? || !@cart.key?(id.to_s)
-    old_quantity = @cart[id.to_s][:quantity] || @cart[id.to_s][:quantity.to_s]
+  def remove_product_item(product_id)
+    @cart.tap { |cart| cart.delete(product_id) } if product_item_exist?(product_id)
+  end
+
+  def product_quantity(product_id, new_quantity = 0)
+    return new_quantity.to_i if @cart.empty? || !product_item_exist?(product_id)
+    old_quantity = @cart[product_id.to_s][:quantity] ||
+                   @cart[product_id.to_s][:quantity.to_s]
     new_quantity.to_i + old_quantity
   end
 
-  def get_all_items
-    line_items = {}
-    @cart.each do |id, attrs|
-      line_items[id] = { product: Product.find(id),
-                         quantity: attrs[:quantity.to_s].to_i }
-    end
-    line_items
+  def can_update_product_item?(product_id, quantity)
+    product_is_in_stock?(product_id, quantity) && product_item_exist?(product_id)
+  end
+
+  def product_is_in_stock?(product_id, quantity)
+    @product.find(product_id).in_stock?(quantity)
   end
 
-  def remove_item(id)
-    @cart.tap { |cart| cart.delete(id) } if @cart.key?(id)
+  def product_item_exist?(product_id)
+    @cart.key?(product_id.to_s)
   end
 
   def cal_total_price
-    get_all_items.sum do |_, attrs|
+    product_items.sum do |_product_id, attrs|
       attrs[:product].price * attrs[:quantity]
     end
   end
 
   def cal_total_items
     return 0 if @cart.nil?
-    @cart.sum { |_, attrs| attrs[:quantity] || attrs[:quantity.to_s] }
+    @cart.sum { |_product_id, attrs| attrs[:quantity] || attrs[:quantity.to_s] }
   end
 end
\ No newline at end of file

app/views/carts/_cart_table.html.erb

@@ -10,8 +10,8 @@
   </tr>
   </thead>
   <tbody>
-  <% @line_items.each do |id, line_item| %>
-      <%= render partial: 'line_item', locals: { id: id, line_item: line_item } %>
+  <% @product_items.each do |id, line_item| %>
+      <%= render partial: 'product_item', locals: { id: id, product_item: line_item } %>
   <% end %>
   </tbody>
   <tfoot>

app/views/carts/_line_item.html.erb → app/views/carts/_product_item.html.erb

 <tr>
   <td class="product-action-td">
-    <%= link_to fa_icon('times'), cart_remove_line_item_path(id), method: :delete, data: { confirm: 'Are you sure?' } %>
+    <%= link_to fa_icon('times'), cart_remove_product_item_path(id), method: :delete, data: { confirm: 'Are you sure?' } %>
   </td>
   <td class="product-image-td"></td>
   <td class="product-name-td">
     <h2 class="product-name">
-      <%= link_to line_item[:product].title, product_url(line_item[:product]) %>
+      <%= link_to product_item[:product].title, product_item_url(product_item[:product]) %>
     </h2>
   </td>
-  <td><%= number_to_currency(line_item[:product].price) %></td>
+  <td><%= number_to_currency(product_item[:product].price) %></td>
   <td>
-    <%= form_tag cart_update_line_item_path(id), method: :put do %>
+    <%= form_tag cart_update_product_item_path(id), method: :put do %>
         <div class="qty-holder">
-          <%= number_field_tag :product_quantity, line_item[:quantity], id: nil, class: 'qty-input' %>
+          <%= number_field_tag :product_quantity, product_item[:quantity], id: nil, class: 'qty-input' %>
         </div>
     <% end %>
   </td>
-  <td><%= number_to_currency(line_item[:product].price * line_item[:quantity]) %></td>
+  <td><%= number_to_currency(product_item[:product].price * product_item[:quantity]) %></td>
 </tr>
\ No newline at end of file

app/views/order_mailer/send_order_detail_to_user.html.erb

@@ -75,7 +75,7 @@
                 <th align="center" bgcolor="#EEEEEE" style="border: 1px solid #CCCCCC;">Price</th>
                 <th align="center" bgcolor="#EEEEEE" style="border: 1px solid #CCCCCC;">Total</th>
               </tr>
-              <% @order.line_items.each do |item| %>
+              <% @order.product_items.each do |item| %>
               <tr valign="top">
                 <td align="left" style="border: 1px solid #CCCCCC;">
                   <%= item.product.id %>

app/views/orders/new.html.erb

@@ -28,8 +28,8 @@
             </tr>
             </thead>
             <tbody>
-            <% @line_items.each do |id, line_item| %>
-                <%= render partial: 'line_items/line_item', locals: {id: id, line_item: line_item} %>
+            <% @order_items.each do |id, product_item| %>
+                <%= render partial: 'product_items/product_item', locals: {id: id, product_item: product_item} %>
             <% end %>
             </tbody>
           </table>

app/views/line_items/_line_item.html.erb → app/views/product_items/_product_item.html.erb

@@ -2,10 +2,10 @@
   <td class="product-image-td"></td>
   <td class="product-name-td">
     <h2 class="product-name">
-      <%= link_to line_item[:product].title, product_url(line_item[:product]) %>
+      <%= link_to product_item[:product].title, product_url(product_item[:product]) %>
     </h2>
   </td>
-  <td><%= number_to_currency(line_item[:product].price) %></td>
-  <td><%= line_item[:quantity]%></td>
-  <td><%= number_to_currency(line_item[:product].price * line_item[:quantity]) %></td>
+  <td><%= number_to_currency(product_item[:product].price) %></td>
+  <td><%= product_item[:quantity]%></td>
+  <td><%= number_to_currency(product_item[:product].price * product_item[:quantity]) %></td>
 </tr>
\ No newline at end of file

app/views/products/_product.html.erb

@@ -26,7 +26,7 @@
           </p>
         </div>
         <div class="product-actions">
-          <%= form_tag cart_add_line_item_path(product.id), remote: true do %>
+          <%= form_tag cart_add_product_item_path(product.id), remote: true do %>
               <div class="product-detail-qty">
                 <%= number_field_tag :product_quantity, 1, min: 0, class: 'vertical-spinner' %>
               </div>

config/routes.rb

@@ -4,12 +4,15 @@ Rails.application.routes.draw do
   resources :categories
   resources :products
   resources :orders, only: [:new, :create, :show]
-  resources :line_items
+  resources :product_items
   scope 'cart' do
     get '/', to: 'carts#index', as: 'cart_index'
-    post '/add/:id', to: 'carts#add_line_item', as: 'cart_add_line_item'
-    put '/update/:id', to: 'carts#update_line_item', as: 'cart_update_line_item'
-    delete '/remove/:id', to: 'carts#remove_line_item', as: 'cart_remove_line_item'
+    post '/add/:product_id', to: 'carts#add_product_item',
+                             as: 'cart_add_product_item'
+    put '/update/:product_id', to: 'carts#update_product_item',
+                               as: 'cart_update_product_item'
+    delete '/remove/:product_id', to: 'carts#remove_product_item',
+                                  as: 'cart_remove_product_item'
     delete '/remove', to: 'carts#destroy', as: 'cart_destroy'
   end
   devise_for :users

db/migrate/20170612023836_create_line_items.rb → db/migrate/20170612023836_create_product_items.rb

-class CreateLineItems < ActiveRecord::Migration[5.1]
+class CreateProductItems < ActiveRecord::Migration[5.1]
   def change
-    create_table :line_items do |t|
+    create_table :product_items do |t|
       t.integer :quantity, default: 1
       t.references :product, index: true
       t.references :order, index: true

db/schema.rb

@@ -17,21 +17,21 @@ ActiveRecord::Schema.define(version: 20170615035827) do
     t.text "description"
   end
 
-  create_table "line_items", force: :cascade, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8" do |t|
-    t.integer "quantity", default: 1
-    t.bigint "product_id"
-    t.bigint "order_id"
+  create_table "orders", force: :cascade, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8" do |t|
+    t.bigint "user_id"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
-    t.index ["order_id"], name: "index_line_items_on_order_id"
-    t.index ["product_id"], name: "index_line_items_on_product_id"
+    t.index ["user_id"], name: "index_orders_on_user_id"
   end
 
-  create_table "orders", force: :cascade, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8" do |t|
-    t.bigint "user_id"
+  create_table "product_items", force: :cascade, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8" do |t|
+    t.integer "quantity", default: 1
+    t.bigint "product_id"
+    t.bigint "order_id"
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
-    t.index ["user_id"], name: "index_orders_on_user_id"
+    t.index ["order_id"], name: "index_product_items_on_order_id"
+    t.index ["product_id"], name: "index_product_items_on_product_id"
   end
 
   create_table "products", force: :cascade, options: "ENGINE=InnoDB DEFAULT CHARSET=utf8" do |t|

lib/cart.rb

-
-class Cart
-  def abc
-    'hi'
-  end
-end
\ No newline at end of file