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/bin/rails new depot --skip-bundle --dev

      create

      create  README

      create  Rakefile

      create  config.ru

      create  .gitignore

      create  Gemfile

      create  app

      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  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/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  log

      create  log/server.log

      create  log/production.log

      create  log/development.log

      create  log/test.log

      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  public/images

      create  public/images/rails.png

      create  public/stylesheets

      create  public/stylesheets/.gitkeep

      create  public/javascripts

      create  public/javascripts/application.js

      create  public/javascripts/controls.js

      create  public/javascripts/dragdrop.js

      create  public/javascripts/effects.js

      create  public/javascripts/prototype.js

      create  public/javascripts/rails.js

      create  script

      create  script/rails

      create  test

      create  test/fixtures

      create  test/functional

      create  test/integration

      create  test/performance/browsing_test.rb

      create  test/test_helper.rb

      create  test/unit

      create  tmp

      create  tmp/sessions

      create  tmp/sockets

      create  tmp/cache

      create  tmp/pids

      create  vendor/plugins

      create  vendor/plugins/.gitkeep

bundle install

Using rake (0.9.2.2)

Using abstract (1.0.0)

Using activesupport (3.0.15)

Using builder (2.1.2)

Using i18n (0.5.0)

Using activemodel (3.0.15)

Using erubis (2.6.6)

Using rack (1.2.5)

Using rack-mount (0.6.14)

Using rack-test (0.5.7)

Using tzinfo (0.3.33)

Using actionpack (3.0.15)

Using mime-types (1.19)

Using polyglot (0.3.3)

Using treetop (1.4.10)

Using mail (2.2.19)

Using actionmailer (3.0.15)

Using arel (2.0.10)

Using activerecord (3.0.15)

Using activeresource (3.0.15)

Using bundler (1.1.3)

Using json (1.7.3)

Using rdoc (3.12)

Using thor (0.14.6)

Using railties (3.0.15)

Using rails (3.0.15)

Using sqlite3 (1.3.6)

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/20120629162929_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  stylesheets

      create    public/stylesheets/scaffold.css

Break lines for formatting reasons

edit app/controllers/products_controller.rb

class ProductsController < ApplicationController

  # GET /products

  # GET /products.xml

  def index

    @products = Product.all

    respond_to do |format|

      format.html # index.html.erb

      format.xml  { render :xml => @products }

end

end

  # GET /products/1

  # GET /products/1.xml

  def show

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

    respond_to do |format|

      format.html # show.html.erb

      format.xml  { render :xml => @product }

end

end

  # GET /products/new

  # GET /products/new.xml

  def new

    @product = Product.new

    respond_to do |format|

      format.html # new.html.erb

      format.xml  { render :xml => @product }

end

end

  # GET /products/1/edit

  def edit

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

end

  # POST /products

  # POST /products.xml

  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.xml  { render :xml => @product, :status => :created,

          :location => @product }

      else

        format.html { render :action => "new" }

        format.xml  { render :xml => @product.errors,

          :status => :unprocessable_entity }

end

end

end

  # PUT /products/1

  # PUT /products/1.xml

  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.xml  { head :ok }

      else

        format.html { render :action => "edit" }

        format.xml  { render :xml => @product.errors,

          :status => :unprocessable_entity }

end

end

end

  # DELETE /products/1

  # DELETE /products/1.xml

  def destroy

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

    @product.destroy

    respond_to do |format|

      format.html { redirect_to(products_url) }

      format.xml  { head :ok }

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/20120629162929_create_products.rb

class CreateProducts < ActiveRecord::Migration

  def self.up

    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

  def self.down

    drop_table :products

end

end

Apply the migration

rake db:migrate

mv 20120629162929_create_products.rb 20110711000001_create_products.rb

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

-- create_table(:products)

   -> 0.0019s

==  CreateProducts: migrated (0.0020s) ========================================

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

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: /images/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>	/images/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-1.8.7-p352/gems/rake-0.9.2.2/lib/rake/rake_test_loader

Started

Finished in 0.212602 seconds.

1 tests, 1 assertions, 0 failures, 0 errors

Loaded suite /home/rubys/.rvm/gems/ruby-1.8.7-p352/gems/rake-0.9.2.2/lib/rake/rake_test_loader

Started

.......

Finished in 0.348707 seconds.

7 tests, 10 assertions, 0 failures, 0 errors

6.2 Iteration A2: Making Prettier Listings 2 Instant Gratification