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

</\d+ (test|run)s, \d+ assertions, 0 failures, 0 errors/> was expected to be =~
<"<pre class=\"stderr\">Expected string default value for '--rc'; got false (boolean)</pre>">.

Traceback:
  /home/rubys/git/awdwr/edition4/checkdepot.rb:70:in `block (3 levels) in <class:DepotTest>'
  /home/rubys/git/awdwr/edition4/checkdepot.rb:69:in `each'
  /home/rubys/git/awdwr/edition4/checkdepot.rb:69:in `block (2 levels) in <class:DepotTest>'
  /home/rubys/git/rails/actionpack/lib/action_dispatch/testing/assertions/selector.rb:305:in `assert_select'
  /home/rubys/git/awdwr/edition4/checkdepot.rb:67:in `block in <class:DepotTest>'

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
Expected string default value for '--rc'; got false (boolean)
      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  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 12.0.0
Using i18n 0.8.4
Using json 1.8.6
Using minitest 5.3.3
Using thread_safe 0.3.6
Using builder 3.2.3
Using erubis 2.7.0
Using rack 1.5.5
Using mime-types-data 3.2016.0521
Using arel 5.0.1.20140414130214
Using bundler 1.15.1
Using thor 0.19.4
Using hike 1.2.3
Using multi_json 1.12.1
Using tilt 1.4.1
Using sqlite3 1.3.13
Using sass 3.2.19
Using execjs 2.7.0
Using coffee-script-source 1.12.2
Using turbolinks-source 5.0.3
Using rdoc 4.3.0
Using spring 1.7.2
Using tzinfo 1.2.3
Using rack-test 0.6.3
Using mime-types 3.1
Using sprockets 2.12.4
Using uglifier 3.2.0
Using coffee-script 2.4.1
Using turbolinks 5.0.1
Using sdoc 0.4.2
Using activesupport 4.1.16 from source at `/home/rubys/git/rails`
Using mail 2.6.5
Using actionview 4.1.16 from source at `/home/rubys/git/rails`
Using activemodel 4.1.16 from source at `/home/rubys/git/rails`
Using jbuilder 2.6.4
Using actionpack 4.1.16 from source at `/home/rubys/git/rails`
Using activerecord 4.1.16 from source at `/home/rubys/git/rails`
Using actionmailer 4.1.16 from source at `/home/rubys/git/rails`
Using railties 4.1.16 from source at `/home/rubys/git/rails`
Using sprockets-rails 2.3.3
Using coffee-rails 4.0.1
Using jquery-rails 3.1.4
Using rails 4.1.16 from source at `/home/rubys/git/rails`
Using sass-rails 4.0.5
Bundle complete! 10 Gemfile dependencies, 44 gems now installed.
Use `bundle info [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/20170603074026_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
      create      app/views/products/_product.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
<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/20170603074026_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 20170603074026_create_products.rb 20170603000001_create_products.rb
== 20170603000001 CreateProducts: migrating ===================================
-- create_table(:products)
   -> 0.0014s
== 20170603000001 CreateProducts: migrated (0.0014s) ==========================
 

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: 10, cols: 60 %>
  </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: Seven Mobile Apps in Seven Weeks

Description: <p> <em>Native Apps, Multiple Platforms</em> Answer the question “Can we build this for ALL the devices?” with a resounding YES. This book will help you get there with a real-world introduction to seven platforms, whether you’re new to mobile or an experienced developer needing to expand your options. Plus, you’ll find out which cross-platform solution makes the most sense for your needs. </p>

Image url: 7apps.jpg

Price: 29.0

Edit | Back

Verify that the product has been added

get /products

Listing products

Title Description Image url Price
Seven Mobile Apps in Seven Weeks <p> <em>Native Apps, Multiple Platforms</em> Answer the question “Can we build this for ALL the devices?” with a resounding YES. This book will help you get there with a real-world introduction to seven platforms, whether you’re new to mobile or an experienced developer needing to expand your options. Plus, you’ll find out which cross-platform solution makes the most sense for your needs. </p> 7apps.jpg 29.0 Show Edit Destroy

New Product

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

rake test
Run options: --seed 18727
 
# Running:
 
.......
 
Finished in 0.303122s, 23.0930 runs/s, 42.8871 assertions/s.
 
7 runs, 13 assertions, 0 failures, 0 errors, 0 skips

6.2 Iteration A2: Making Prettier Listings 2 Instant Gratification