Iteration D2.

app/assets/javascripts/line_items.coffee

@@ -0,0 +1,3 @@
+# Place all the behaviors and hooks related to the matching controller here.
+# All this logic will automatically be available in application.js.
+# You can use CoffeeScript in this file: http://coffeescript.org/

app/assets/stylesheets/line_items.scss

@@ -0,0 +1,3 @@
+// Place all the styles related to the LineItems controller here.
+// They will automatically be included in application.css.
+// You can use Sass (SCSS) here: http://sass-lang.com/

app/controllers/line_items_controller.rb

@@ -0,0 +1,74 @@
+class LineItemsController < ApplicationController
+  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
+    @line_item = LineItem.new(line_item_params)
+
+    respond_to do |format|
+      if @line_item.save
+        format.html { redirect_to @line_item, notice: 'Line item was successfully created.' }
+        format.json { render :show, status: :created, location: @line_item }
+      else
+        format.html { render :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, notice: 'Line item was successfully updated.' }
+        format.json { render :show, status: :ok, location: @line_item }
+      else
+        format.html { render :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, notice: 'Line item was successfully destroyed.' }
+      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, :cart_id)
+    end
+end

app/helpers/line_items_helper.rb

@@ -0,0 +1,2 @@
+module LineItemsHelper
+end

app/models/cart.rb

@@ -1,2 +1,3 @@
 class Cart < ApplicationRecord
+  has_many :line_items, dependent: :destroy
 end

app/models/line_item.rb

@@ -0,0 +1,4 @@
+class LineItem < ApplicationRecord
+  belongs_to :product
+  belongs_to :cart
+end

app/models/product.rb

@@ -1,4 +1,8 @@
 class Product < ApplicationRecord
+  has_many :line_items
+
+  before_destroy :ensure_not_referenced_by_any_line_item
+
   validates :title, :description, :image_url, :price, presence: true
   validates :price, numericality: {greater_than_or_equal_to: 0.01}
   validates :title, uniqueness: true, length: { minimum: 5, maximum: 30 }
@@ -6,4 +10,12 @@ class Product < ApplicationRecord
     with: %r{\.(gif|jpg|png)\Z}i,
     message: 'must be URL for GIF, JPG or PNG image.'
   }
+
+  private
+    def ensure_not_referenced_by_any_line_item
+      unless line_items.empty?
+        errors.add(:base, 'Line Items present')
+        throw :abort
+      end
+    end
 end

app/views/line_items/_form.html.erb

@@ -0,0 +1,27 @@
+<%= form_for(line_item) do |f| %>
+  <% if line_item.errors.any? %>
+    <div id="error_explanation">
+      <h2><%= pluralize(line_item.errors.count, "error") %> prohibited this line_item from being saved:</h2>
+
+      <ul>
+      <% line_item.errors.full_messages.each do |message| %>
+        <li><%= message %></li>
+      <% end %>
+      </ul>
+    </div>
+  <% end %>
+
+  <div class="field">
+    <%= f.label :product_id %>
+    <%= f.text_field :product_id %>
+  </div>
+
+  <div class="field">
+    <%= f.label :cart_id %>
+    <%= f.text_field :cart_id %>
+  </div>
+
+  <div class="actions">
+    <%= f.submit %>
+  </div>
+<% end %>

app/views/line_items/_line_item.json.jbuilder

@@ -0,0 +1,2 @@
+json.extract! line_item, :id, :product_id, :cart_id, :created_at, :updated_at
+json.url line_item_url(line_item, format: :json)

app/views/line_items/edit.html.erb

@@ -0,0 +1,6 @@
+<h1>Editing Line Item</h1>
+
+<%= render 'form', line_item: @line_item %>
+
+<%= link_to 'Show', @line_item %> |
+<%= link_to 'Back', line_items_path %>

app/views/line_items/index.html.erb

@@ -0,0 +1,29 @@
+<p id="notice"><%= notice %></p>
+
+<h1>Line Items</h1>
+
+<table>
+  <thead>
+    <tr>
+      <th>Product</th>
+      <th>Cart</th>
+      <th colspan="3"></th>
+    </tr>
+  </thead>
+
+  <tbody>
+    <% @line_items.each do |line_item| %>
+      <tr>
+        <td><%= line_item.product %></td>
+        <td><%= line_item.cart %></td>
+        <td><%= link_to 'Show', line_item %></td>
+        <td><%= link_to 'Edit', edit_line_item_path(line_item) %></td>
+        <td><%= link_to 'Destroy', line_item, method: :delete, data: { confirm: 'Are you sure?' } %></td>
+      </tr>
+    <% end %>
+  </tbody>
+</table>
+
+<br>
+
+<%= link_to 'New Line Item', new_line_item_path %>

app/views/line_items/index.json.jbuilder

@@ -0,0 +1 @@
+json.array! @line_items, partial: 'line_items/line_item', as: :line_item

app/views/line_items/new.html.erb

@@ -0,0 +1,5 @@
+<h1>New Line Item</h1>
+
+<%= render 'form', line_item: @line_item %>
+
+<%= link_to 'Back', line_items_path %>

app/views/line_items/show.html.erb

@@ -0,0 +1,14 @@
+<p id="notice"><%= notice %></p>
+
+<p>
+  <strong>Product:</strong>
+  <%= @line_item.product %>
+</p>
+
+<p>
+  <strong>Cart:</strong>
+  <%= @line_item.cart %>
+</p>
+
+<%= link_to 'Edit', edit_line_item_path(@line_item) %> |
+<%= link_to 'Back', line_items_path %>

app/views/line_items/show.json.jbuilder

@@ -0,0 +1 @@
+json.partial! "line_items/line_item", line_item: @line_item

config/routes.rb

@@ -1,4 +1,5 @@
 Rails.application.routes.draw do
+  resources :line_items
   resources :carts
   root 'store#index', as: 'store_index'
 

db/migrate/20161115211138_create_line_items.rb

@@ -0,0 +1,10 @@
+class CreateLineItems < ActiveRecord::Migration[5.0]
+  def change
+    create_table :line_items do |t|
+      t.references :product, foreign_key: true
+      t.belongs_to :cart, foreign_key: true
+
+      t.timestamps
+    end
+  end
+end

db/schema.rb

@@ -10,13 +10,22 @@
 #
 # It's strongly recommended that you check this file into your version control system.
 
-ActiveRecord::Schema.define(version: 20161115210150) do
+ActiveRecord::Schema.define(version: 20161115211138) do
 
   create_table "carts", force: :cascade do |t|
     t.datetime "created_at", null: false
     t.datetime "updated_at", null: false
   end
 
+  create_table "line_items", force: :cascade do |t|
+    t.integer  "product_id"
+    t.integer  "cart_id"
+    t.datetime "created_at", null: false
+    t.datetime "updated_at", null: false
+    t.index ["cart_id"], name: "index_line_items_on_cart_id"
+    t.index ["product_id"], name: "index_line_items_on_product_id"
+  end
+
   create_table "products", force: :cascade do |t|
     t.string   "title"
     t.text     "description"

test/controllers/line_items_controller_test.rb

@@ -0,0 +1,48 @@
+require 'test_helper'
+
+class LineItemsControllerTest < ActionDispatch::IntegrationTest
+  setup do
+    @line_item = line_items(:one)
+  end
+
+  test "should get index" do
+    get line_items_url
+    assert_response :success
+  end
+
+  test "should get new" do
+    get new_line_item_url
+    assert_response :success
+  end
+
+  test "should create line_item" do
+    assert_difference('LineItem.count') do
+      post line_items_url, params: { line_item: { cart_id: @line_item.cart_id, product_id: @line_item.product_id } }
+    end
+
+    assert_redirected_to line_item_url(LineItem.last)
+  end
+
+  test "should show line_item" do
+    get line_item_url(@line_item)
+    assert_response :success
+  end
+
+  test "should get edit" do
+    get edit_line_item_url(@line_item)
+    assert_response :success
+  end
+
+  test "should update line_item" do
+    patch line_item_url(@line_item), params: { line_item: { cart_id: @line_item.cart_id, product_id: @line_item.product_id } }
+    assert_redirected_to line_item_url(@line_item)
+  end
+
+  test "should destroy line_item" do
+    assert_difference('LineItem.count', -1) do
+      delete line_item_url(@line_item)
+    end
+
+    assert_redirected_to line_items_url
+  end
+end

test/controllers/products_controller_test.rb

@@ -44,6 +44,14 @@ class ProductsControllerTest < ActionDispatch::IntegrationTest
     assert_redirected_to product_url(@product)
   end
 
+  test "can't delete product in cart" do
+    assert_difference('Product.count', 0) do
+      delete product_url(products(:two))
+    end
+
+    assert_redirected_to products_url
+  end
+
   test "should destroy product" do
     assert_difference('Product.count', -1) do
       delete product_url(@product)
@@ -51,4 +59,7 @@ class ProductsControllerTest < ActionDispatch::IntegrationTest
 
     assert_redirected_to products_url
   end
+
+
+
 end

test/fixtures/line_items.yml

@@ -0,0 +1,10 @@
+# Read about fixtures at http://api.rubyonrails.org/classes/ActiveRecord/FixtureSet.html
+# TODO: Warum hat das hier nicht funktioniert wenn das beides in einem eigenen Cart lag?
+
+one:
+  product: two
+  cart: one
+
+two:
+  product: two
+  cart: two

test/models/line_item_test.rb

@@ -0,0 +1,7 @@
+require 'test_helper'
+
+class LineItemTest < ActiveSupport::TestCase
+  # test "the truth" do
+  #   assert true
+  # end
+end