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 --dev

      create

      create  README

      create  Rakefile

      create  config.ru

      create  .gitignore

      create  Gemfile

      create  app

      create  app/assets/images/rails.png

      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/mailers

      create  app/models

      create  app/views/layouts/application.html.erb

      create  app/mailers/.gitkeep

      create  app/models/.gitkeep

      create  config

      create  config/routes.rb

      create  config/application.rb

      create  config/environment.rb

      create  config/environments

      create  config/environments/development.rb

      create  config/environments/production.rb

      create  config/environments/test.rb

      create  config/initializers

      create  config/initializers/backtrace_silencers.rb

      create  config/initializers/inflections.rb

      create  config/initializers/mime_types.rb

      create  config/initializers/secret_token.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  doc

      create  doc/README_FOR_APP

      create  lib

      create  lib/tasks

      create  lib/tasks/.gitkeep

      create  lib/assets

      create  lib/assets/.gitkeep

      create  log

      create  log/.gitkeep

      create  public

      create  public/404.html

      create  public/422.html

      create  public/500.html

      create  public/favicon.ico

      create  public/index.html

      create  public/robots.txt

      create  script

      create  script/rails

      create  test/fixtures

      create  test/fixtures/.gitkeep

      create  test/functional

      create  test/functional/.gitkeep

      create  test/integration

      create  test/integration/.gitkeep

      create  test/unit

      create  test/unit/.gitkeep

      create  test/performance/browsing_test.rb

      create  test/test_helper.rb

      create  tmp/cache

      create  tmp/cache/assets

      create  vendor/assets/javascripts

      create  vendor/assets/javascripts/.gitkeep

      create  vendor/assets/stylesheets

      create  vendor/assets/stylesheets/.gitkeep

      create  vendor/plugins

      create  vendor/plugins/.gitkeep

bundle install

Using rake (0.9.2.2)

Using i18n (0.6.0)

Using multi_json (1.0.3)

Using activesupport (3.2.0.beta)

Using builder (3.0.0)

Using activemodel (3.2.0.beta)

Using erubis (2.7.0)

Using journey (1.0.0.20111022124133)

Using rack (1.3.5)

Using rack-cache (1.1)

Using rack-test (0.6.1)

Using hike (1.2.1)

Using tilt (1.3.3)

Using sprockets (2.0.3)

Using actionpack (3.2.0.beta)

Using mime-types (1.17.2)

Using polyglot (0.3.2)

Using treetop (1.4.10)

Using mail (2.3.0)

Using actionmailer (3.2.0.beta)

Using arel (2.2.1)

Using tzinfo (0.3.30)

Using activerecord (3.2.0.beta)

Using activeresource (3.2.0.beta)

Using bundler (1.0.21)

Using coffee-script-source (1.1.2)

Using execjs (1.2.9)

Using coffee-script (2.2.0)

Using rack-ssl (1.3.2)

Using json (1.6.1)

Using rdoc (3.11)

Using thor (0.14.6)

Using railties (3.2.0.beta)

Using coffee-rails (3.2.0.beta)

Using jquery-rails (1.0.16)

Using rails (3.2.0.beta)

Using sass (3.1.10)

Using sass-rails (3.1.1.alpha.0)

Using sqlite3 (1.3.4)

Using uglifier (1.0.4)

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.ru  doc/     Gemfile.lock  log/     Rakefile  script/  tmp/

config/  db/	    Gemfile  lib/	   public/  README    test/    vendor/

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/20111029071111_create_products.rb

      create    app/models/product.rb

      invoke    test_unit

      create      test/unit/product_test.rb

      create      test/fixtures/products.yml

       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/functional/products_controller_test.rb

      invoke    helper

      create      app/helpers/products_helper.rb

      invoke      test_unit

      create        test/unit/helpers/products_helper_test.rb

      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

  # GET /products

  # GET /products.json

  def index

    @products = Product.all

    respond_to do |format|

      format.html # index.html.erb

      format.json { render json: @products }

end

end

  # GET /products/1

  # GET /products/1.json

  def show

    @product = Product.find(params[:id])

    respond_to do |format|

      format.html # show.html.erb

      format.json { render json: @product }

end

end

  # GET /products/new

  # GET /products/new.json

  def new

    @product = Product.new

    respond_to do |format|

      format.html # new.html.erb

      format.json { render json: @product }

end

end

  # GET /products/1/edit

  def edit

    @product = Product.find(params[:id])

end

  # POST /products

  # POST /products.json

  def create

    @product = Product.new(params[:product])

    respond_to do |format|

      if @product.save

        format.html { redirect_to @product,

          notice: 'Product was successfully created.' }

        format.json { render json: @product, status: :created,

          location: @product }

      else

        format.html { render action: "new" }

        format.json { render json: @product.errors,

          status: :unprocessable_entity }

end

end

end

  # PUT /products/1

  # PUT /products/1.json

  def update

    @product = Product.find(params[:id])

    respond_to do |format|

      if @product.update_attributes(params[:product])

        format.html { redirect_to @product,

          notice: 'Product was successfully updated.' }

        format.json { head :no_content }

      else

        format.html { render action: "edit" }

        format.json { render json: @product.errors,

          status: :unprocessable_entity }

end

end

end

  # DELETE /products/1

  # DELETE /products/1.json

  def destroy

    @product = Product.find(params[:id])

    @product.destroy

    respond_to do |format|

      format.html { redirect_to products_url }

      format.json { head :no_content }

end

end

end

edit app/views/products/index.html.erb

<h1>Listing products</h1>

<table>

  <tr>

    <th>Title</th>

    <th>Description</th>

    <th>Image url</th>

    <th>Price</th>

    <th></th>

    <th></th>

    <th></th>

  </tr>

<% @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, confirm: 'Are you sure?',

            method: :delete %></td>

  </tr>

<% end %>

</table>

<br />

<%= link_to 'New Product', new_product_path %>

Add precision and scale to the price

edit db/migrate/20111029071111_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 20111029071111_create_products.rb 20110711000001_create_products.rb

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

-- create_table(:products)

   -> 0.0035s

==  CreateProducts: migrated (0.0036s) ========================================

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 |msg| %>

        <li><%= msg %></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

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

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

Loaded suite /home/rubys/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2.2/lib/rake/rake_test_loader

Started

Finished in 0.003336 seconds.

0 tests, 0 assertions, 0 failures, 0 errors, 0 skips

Test run options: --seed 14342

Loaded suite /home/rubys/.rvm/gems/ruby-1.9.2-p290/gems/rake-0.9.2.2/lib/rake/rake_test_loader

Started

.......

Finished in 0.532832 seconds.

7 tests, 10 assertions, 0 failures, 0 errors, 0 skips

Test run options: --seed 31386

6.2 Iteration A2: Making Prettier Listings 2 Instant Gratification