Agile Web Development with Rails, Edition 4

6.2 Iteration A2: Making Prettier Listings 2 Instant Gratification

6.1 Iteration A1: Creating the Products Maintenance Application

This section mostly covers database configuration options for those users that insist on using MySQL. SQLite3 users will skip most of it.

Create the application.

bundle exec /home/rubys/git/rails/railties/bin/rails new depot --skip-bundle
      create  
      create  README.rdoc
      create  Rakefile
      create  config.ru
      create  .gitignore
      create  Gemfile
      create  app
      create  app/assets/javascripts/application.js
      create  app/assets/stylesheets/application.css
      create  app/controllers/application_controller.rb
      create  app/helpers/application_helper.rb
      create  app/views/layouts/application.html.erb
      create  app/assets/images/.keep
      create  app/mailers/.keep
      create  app/models/.keep
      create  app/controllers/concerns/.keep
      create  app/models/concerns/.keep
      create  bin
      create  bin/bundle
      create  bin/rails
      create  bin/rake
      create  bin/setup
      create  config
      create  config/routes.rb
      create  config/application.rb
      create  config/environment.rb
      create  config/secrets.yml
      create  config/environments
      create  config/environments/development.rb
      create  config/environments/production.rb
      create  config/environments/test.rb
      create  config/initializers
      create  config/initializers/assets.rb
      create  config/initializers/backtrace_silencers.rb
      create  config/initializers/cookies_serializer.rb
      create  config/initializers/filter_parameter_logging.rb
      create  config/initializers/inflections.rb
      create  config/initializers/mime_types.rb
      create  config/initializers/session_store.rb
      create  config/initializers/wrap_parameters.rb
      create  config/locales
      create  config/locales/en.yml
      create  config/boot.rb
      create  config/database.yml
      create  db
      create  db/seeds.rb
      create  lib
      create  lib/tasks
      create  lib/tasks/.keep
      create  lib/assets
      create  lib/assets/.keep
      create  log
      create  log/.keep
      create  public
      create  public/404.html
      create  public/422.html
      create  public/500.html
      create  public/favicon.ico
      create  public/robots.txt
      create  test/fixtures
      create  test/fixtures/.keep
      create  test/controllers
      create  test/controllers/.keep
      create  test/mailers
      create  test/mailers/.keep
      create  test/models
      create  test/models/.keep
      create  test/helpers
      create  test/helpers/.keep
      create  test/integration
      create  test/integration/.keep
      create  test/test_helper.rb
      create  tmp/cache
      create  tmp/cache/assets
      create  vendor/assets/javascripts
      create  vendor/assets/javascripts/.keep
      create  vendor/assets/stylesheets
      create  vendor/assets/stylesheets/.keep
bundle install --local
Resolving dependencies...
Using rake 10.3.2
Using i18n 0.7.0.dev from source at /home/rubys/git/i18n
Using json 1.8.1
Using minitest 5.4.0
Using thread_safe 0.3.4
Using tzinfo 1.2.1
Using activesupport 4.2.0.alpha from source at /home/rubys/git/rails
Using builder 3.2.2
Using erubis 2.7.0
Using actionview 4.2.0.alpha from source at /home/rubys/git/rails
Using rack 1.6.0.alpha from source at /home/rubys/git/rack
Using rack-test 0.6.2
Using actionpack 4.2.0.alpha from source at /home/rubys/git/rails
Using mime-types 2.3
Using mail 2.6.1
Using actionmailer 4.2.0.alpha from source at /home/rubys/git/rails
Using activemodel 4.2.0.alpha from source at /home/rubys/git/rails
Using arel 6.0.0.20140505020427 from source at /home/rubys/git/arel
Using activerecord 4.2.0.alpha from source at /home/rubys/git/rails
Using bundler 1.6.5
Using coffee-script-source 1.7.1
Using execjs 2.2.1
Using coffee-script 2.3.0
Using thor 0.19.1
Using railties 4.2.0.alpha from source at /home/rubys/git/rails
Using coffee-rails 4.0.1 from source at /home/rubys/git/coffee-rails
Using hike 1.2.3
Using multi_json 1.10.1
Using jbuilder 2.1.3
Using jquery-rails 3.1.1
Using tilt 1.4.1
Using sprockets 2.12.1
Using sprockets-rails 2.1.2 from source at /home/rubys/git/sprockets-rails
Using rails 4.2.0.alpha from source at /home/rubys/git/rails
Using rdoc 4.1.1
Using sass 3.3.12
Using sass-rails 5.0.0.dev from source at /home/rubys/git/sass-rails
Using sdoc 0.4.0
Using spring 1.1.3
Using sqlite3 1.3.9
Using turbolinks 2.2.2
Using uglifier 2.5.3
Your bundle is complete!
Use `bundle show [gemname]` to see where a bundled gem is installed.

Look at the files created.

ls -p
app/  config/	 db/	  Gemfile.lock	log/	 Rakefile     test/  vendor/
bin/  config.ru  Gemfile  lib/		public/  README.rdoc  tmp/

Generate scaffolding for a real model, modify a template, and do our first bit of data entry.

Generating our first model and associated scaffolding

rails generate scaffold Product title:string description:text image_url:string price:decimal
      invoke  active_record
      create    db/migrate/20140731104031_create_products.rb
      create    app/models/product.rb
      invoke    test_unit
      create      test/models/product_test.rb
      create      test/fixtures/products.yml
      invoke  resource_route
       route    resources :products
      invoke  scaffold_controller
      create    app/controllers/products_controller.rb
      invoke    erb
      create      app/views/products
      create      app/views/products/index.html.erb
      create      app/views/products/edit.html.erb
      create      app/views/products/show.html.erb
      create      app/views/products/new.html.erb
      create      app/views/products/_form.html.erb
      invoke    test_unit
      create      test/controllers/products_controller_test.rb
      invoke    helper
      create      app/helpers/products_helper.rb
      invoke      test_unit
      create        test/helpers/products_helper_test.rb
      invoke    jbuilder
      create      app/views/products/index.json.jbuilder
      create      app/views/products/show.json.jbuilder
      invoke  assets
      invoke    coffee
      create      app/assets/javascripts/products.js.coffee
      invoke    scss
      create      app/assets/stylesheets/products.css.scss
      invoke  scss
      create    app/assets/stylesheets/scaffolds.css.scss

Break lines for formatting reasons

edit app/controllers/products_controller.rb
class ProductsController < ApplicationController
  before_action :set_product, only: [:show, :edit, :update, :destroy]
 
  # GET /products
  # GET /products.json
  def index
    @products = Product.all
  end
 
  # GET /products/1
  # GET /products/1.json
  def show
  end
 
  # GET /products/new
  def new
    @product = Product.new
  end
 
  # GET /products/1/edit
  def edit
  end
 
  # POST /products
  # POST /products.json
  def create
    @product = Product.new(product_params)
 
    respond_to do |format|
      if @product.save
        format.html { redirect_to @product,
          notice: 'Product was successfully created.' }
        format.json { render :show, status: :created,
          location: @product }
      else
        format.html { render :new }
        format.json { render json: @product.errors,
          status: :unprocessable_entity }
      end
    end
  end
 
  # PATCH/PUT /products/1
  # PATCH/PUT /products/1.json
  def update
    respond_to do |format|
      if @product.update(product_params)
        format.html { redirect_to @product,
          notice: 'Product was successfully updated.' }
        format.json { render :show, status: :ok, location: @product }
      else
        format.html { render :edit }
        format.json { render json: @product.errors,
          status: :unprocessable_entity }
      end
    end
  end
 
  # DELETE /products/1
  # DELETE /products/1.json
  def destroy
    @product.destroy
    respond_to do |format|
      format.html { redirect_to products_url,
          notice: 'Product was successfully destroyed.' }
      format.json { head :no_content }
    end
  end
 
  private
    # Use callbacks to share common setup or constraints between actions.
    def set_product
      @product = Product.find(params[:id])
    end
 
    # Never trust parameters from the scary internet, only allow the white
    # list through.
    def product_params
      params.require(:product).permit(:title, :description, :image_url, :price)
    end
end
edit app/views/products/index.html.erb
<p id="notice"><%= notice %></p>
 
<h1>Listing Products</h1>
 
<table>
  <thead>
    <tr>
      <th>Title</th>
      <th>Description</th>
      <th>Image url</th>
      <th>Price</th>
      <th colspan="3"></th>
    </tr>
  </thead>
 
  <tbody>
    <% @products.each do |product| %>
      <tr>
        <td><%= product.title %></td>
        <td><%= product.description %></td>
        <td><%= product.image_url %></td>
        <td><%= product.price %></td>
        <td><%= link_to 'Show', product %></td>
        <td><%= link_to 'Edit', edit_product_path(product) %></td>
        <td><%= link_to 'Destroy', product,
            method: :delete, data: { confirm: 'Are you sure?' } %></td>
      </tr>
    <% end %>
  </tbody>
</table>
 
<br>
 
<%= link_to 'New Product', new_product_path %>

Add precision and scale to the price

edit db/migrate/20140731104031_create_products.rb
class CreateProducts < ActiveRecord::Migration
  def change
    create_table :products do |t|
      t.string :title
      t.text :description
      t.string :image_url
      t.decimal :price, precision: 8, scale: 2
 
      t.timestamps
    end
  end
end

Apply the migration

rake db:migrate
mv 20140731104031_create_products.rb 20140731000001_create_products.rb
== 20140731000001 CreateProducts: migrating ===================================
-- create_table(:products)
   -> 0.0009s
== 20140731000001 CreateProducts: migrated (0.0009s) ==========================
 

Restart the server.

Get an (empty) list of products

get /products

Listing Products

Title Description Image url Price

New Product

Show (and modify) one of the templates produced

edit app/views/products/_form.html.erb
<%= form_for(@product) do |f| %>
  <% if @product.errors.any? %>
    <div id="error_explanation">
      <h2><%= pluralize(@product.errors.count, "error") %>
      prohibited this product from being saved:</h2>
 
      <ul>
      <% @product.errors.full_messages.each do |message| %>
        <li><%= message %></li>
      <% end %>
      </ul>
    </div>
  <% end %>
 
  <div class="field">
    <%= f.label :title %><br>
    <%= f.text_field :title %>
  </div>
  <div class="field">
    <%= f.label :description %><br>
    <%= f.text_area :description, rows: 6 %>
  </div>
  <div class="field">
    <%= f.label :image_url %><br>
    <%= f.text_field :image_url %>
  </div>
  <div class="field">
    <%= f.label :price %><br>
    <%= f.text_field :price %>
  </div>
  <div class="actions">
    <%= f.submit %>
  </div>
<% end %>

Create a product

get /products/new

New Product





Back
post /products
You are being redirected.
get http://localhost:3000/products/1

Product was successfully created.

Title: CoffeeScript

Description: <p> CoffeeScript is JavaScript done right. It provides all of JavaScript's functionality wrapped in a cleaner, more succinct syntax. In the first book on this exciting new language, CoffeeScript guru Trevor Burnham shows you how to hold onto all the power and flexibility of JavaScript while writing clearer, cleaner, and safer code. </p>

Image url: cs.jpg

Price: 29.0

Edit | Back

Verify that the product has been added

get /products

Listing Products

Title Description Image url Price
CoffeeScript <p> CoffeeScript is JavaScript done right. It provides all of JavaScript's functionality wrapped in a cleaner, more succinct syntax. In the first book on this exciting new language, CoffeeScript guru Trevor Burnham shows you how to hold onto all the power and flexibility of JavaScript while writing clearer, cleaner, and safer code. </p> cs.jpg 29.0 Show Edit Destroy

New Product

And, just to verify that we haven't broken anything

rake test
Run options: --seed 17028
 
# Running:
 
.......
 
Finished in 0.422260s, 16.5774 runs/s, 30.7867 assertions/s.
 
7 runs, 13 assertions, 0 failures, 0 errors, 0 skips

6.2 Iteration A2: Making Prettier Listings 2 Instant Gratification