6.2 Iteration A2: Making Prettier Listings 2 Instant Gratification

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  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 10.5.0

Using i18n 0.7.0

Using json 1.8.3

Using minitest 5.8.4

Using thread_safe 0.3.5

Using builder 3.2.2

Using erubis 2.7.0

Using rack 1.5.5

Using mime-types 2.99.1

Using arel 5.0.1.20140414130214

Using bundler 1.11.2

Using coffee-script-source 1.10.0

Using execjs 2.6.0

Using thor 0.19.1

Using hike 1.2.3

Using multi_json 1.11.2

Using tilt 1.4.1

Using sass 3.2.19

Using spring 1.6.4

Using sqlite3 1.3.11

Using rdoc 4.2.2

Using tzinfo 1.2.2

Using rack-test 0.6.3

Using mail 2.6.3

Using coffee-script 2.4.1

Using uglifier 2.7.2

Using sprockets 2.12.4

Using sdoc 0.4.1

Using activesupport 4.1.14.2 from source at `/home/rubys/git/rails`

Using actionview 4.1.14.2 from source at `/home/rubys/git/rails`

Using activemodel 4.1.14.2 from source at `/home/rubys/git/rails`

Using jbuilder 2.4.1

Using actionpack 4.1.14.2 from source at `/home/rubys/git/rails`

Using activerecord 4.1.14.2 from source at `/home/rubys/git/rails`

Using actionmailer 4.1.14.2 from source at `/home/rubys/git/rails`

Using railties 4.1.14.2 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 4.1.14.2 from source at `/home/rubys/git/rails`

Using sass-rails 4.0.5

Using turbolinks 2.5.3

Bundle complete! 10 Gemfile dependencies, 42 gems now installed.

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/20160306174035_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

<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/20160306174035_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 20160306174035_create_products.rb 20160306000001_create_products.rb

== 20160306000001 CreateProducts: migrating ===================================

-- create_table(:products)

   -> 0.0008s

== 20160306000001 CreateProducts: migrated (0.0008s) ==========================

Restart the server.

Get an (empty) list of products

get /products

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

post /products

• product[title] => CoffeeScript
• product[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>
• product[price] => 29.00
• product[image_url] => cs.jpg

get http://localhost:3000/products/1

Verify that the product has been added

get /products

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

rake test

Run options: --seed 29370

# Running:

.......

Finished in 0.444973s, 15.7313 runs/s, 29.2152 assertions/s.

7 runs, 13 assertions, 0 failures, 0 errors, 0 skips

6.2 Iteration A2: Making Prettier Listings 2 Instant Gratification