Agile Web Development with Rails, Edition 4

Agile Web Development with Rails, Edition 4

6.1 Iteration A1: Creating the Products Maintenance Application Table of Contents

2 Instant Gratification

We start with a simple "hello world!" demo application and in the process verify that everything is installed correctly.

Create the application

bundle exec /home/rubys/git/rails/railties/bin/rails new demo1 --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 active_utils (1.0.1) 
Using braintree (2.12.0) 
Using json (1.6.1) 
Using money (3.7.1) 
Using activemerchant (1.18.1) 
Using arel (2.2.1) 
Using tzinfo (0.3.30) 
Using activerecord (3.2.0.beta) 
Using activeresource (3.2.0.beta) 
Using bcrypt-ruby (3.0.1) 
Using bundler (1.0.21) 
Using highline (1.6.2) 
Using net-ssh (2.2.1) 
Using net-scp (1.0.4) 
Using net-sftp (2.0.5) 
Using net-ssh-gateway (1.1.0) 
Using capistrano (2.9.0) 
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 rdoc (3.11) 
Using thor (0.14.6) 
Using railties (3.2.0.beta) 
Using coffee-rails (3.2.0.beta) 
Using haml (3.1.3) 
Using htmlentities (4.3.0) 
Using jquery-rails (1.0.16) 
Using mysql2 (0.3.7) 
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 test-unit (2.4.0) 
Using uglifier (1.0.4) 
Using will_paginate (3.0.2) 
Your bundle is complete! Use `bundle show [gemname]` to see where a bundled gem is installed.

See what files were created

ls -p
app/	 config.ru  doc/     lib/  public/   README   test/  vendor/
config/  db/	    Gemfile  log/  Rakefile  script/  tmp/

Create a simple controller

rails generate controller Say hello goodbye
      create  app/controllers/say_controller.rb
       route  get "say/goodbye"
       route  get "say/hello"
      invoke  erb
      create    app/views/say
      create    app/views/say/hello.html.erb
      create    app/views/say/goodbye.html.erb
      invoke  test_unit
      create    test/functional/say_controller_test.rb
      invoke  helper
      create    app/helpers/say_helper.rb
      invoke    test_unit
      create      test/unit/helpers/say_helper_test.rb
      invoke  assets
      invoke    coffee
      create      app/assets/javascripts/say.js.coffee
      invoke    scss
      create      app/assets/stylesheets/say.css.scss
edit app/controllers/say_controller.rb
class SayController < ApplicationController
  def hello
  end
 
  def goodbye
  end
 
end

Start the server.

Attempt to fetch the file - note that it is missing

get /say/hello

Say#hello

Find me in app/views/say/hello.html.erb

Replace file with a simple hello world

edit app/views/say/hello.html.erb
<h1>Hello from Rails!</h1>

This time it works!

get /say/hello

Hello from Rails!

Add a simple expression

edit app/views/say/hello.html.erb
<h1>Hello from Rails!</h1>
<p>
  It is now <%= Time.now %>
</p>
get /say/hello

Hello from Rails!

It is now 2011-10-29 03:10:59 -0400

Evaluate the expression in the controller.

edit app/controllers/say_controller.rb
class SayController < ApplicationController
  def hello
    @time = Time.now
  end
  def goodbye
  end
 
end

Reference the result in the view.

edit app/views/say/hello.html.erb
<h1>Hello from Rails!</h1>
<p>
  It is now <%= @time %>
</p>
get /say/hello

Hello from Rails!

It is now 2011-10-29 03:10:59 -0400

Replace the goodbye template

edit app/views/say/goodbye.html.erb
<h1>Goodbye!</h1>
<p>
  It was nice having you here.
</p>
get /say/goodbye

Goodbye!

It was nice having you here.

Add a link from the hello page to the goodbye page

edit app/views/say/hello.html.erb
<h1>Hello from Rails!</h1>
<p>
  It is now <%= @time %>
</p>
<p>
  Time to say
  <%= link_to "Goodbye", say_goodbye_path %>!
</p>
get /say/hello

Hello from Rails!

It is now 2011-10-29 03:11:00 -0400

Time to say Goodbye!

Add a link back to the hello page

edit app/views/say/goodbye.html.erb
<h1>Goodbye!</h1>
<p>
  It was nice having you here.
</p>
<p>
  Say <%= link_to "Hello", say_hello_path %> again.
</p>
get /say/goodbye

Goodbye!

It was nice having you here.

Say Hello again.

6.1 Iteration A1: Creating the Products Maintenance Application Table of Contents