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
      create  
      create  README.rdoc
      create  Rakefile
      create  config.ru
      create  .gitignore
      create  Gemfile
      create  app
      create  app/assets/images/.keep
      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/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/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/filter_parameter_logging.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  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
Resolving dependencies...
Using rake (10.0.4) 
Using i18n (0.6.4) 
Using minitest (4.7.3) 
Using multi_json (1.7.2) 
Using atomic (1.1.8) 
Using thread_safe (0.1.0) 
Using tzinfo (0.3.37) 
Using activesupport (4.0.0.beta1) from source at /home/rubys/git/rails 
Using builder (3.1.4) 
Using erubis (2.7.0) 
Using rack (1.5.2) 
Using rack-test (0.6.2) 
Using actionpack (4.0.0.beta1) from source at /home/rubys/git/rails 
Using mime-types (1.23) 
Using polyglot (0.3.3) 
Using treetop (1.4.12) 
Using mail (2.5.3) 
Using actionmailer (4.0.0.beta1) from source at /home/rubys/git/rails 
Using activemodel (4.0.0.beta1) from source at /home/rubys/git/rails 
Using activerecord-deprecated_finders (1.0.1) 
Using arel (4.0.0.20130418133826) from source at /home/rubys/git/arel 
Using activerecord (4.0.0.beta1) from source at /home/rubys/git/rails 
Using bundler (1.3.5) 
Using coffee-script-source (1.6.2) 
Using execjs (1.4.0) 
Using coffee-script (2.2.0) 
Using thor (0.18.1) 
Using railties (4.0.0.beta1) from source at /home/rubys/git/rails 
Using coffee-rails (4.0.0) from source at /home/rubys/git/coffee-rails 
Using hike (1.2.2) 
Using jbuilder (1.0.2) 
Using jquery-rails (2.2.1) 
Using json (1.7.7) 
Using tilt (1.3.7) 
Using sprockets (2.9.3) 
Using sprockets-rails (2.0.0.rc4) from source at /home/rubys/git/sprockets-rails 
Using rails (4.0.0.beta1) from source at /home/rubys/git/rails 
Using rdoc (3.12.2) 
Using sass (3.2.8) 
Using sass-rails (4.0.0.rc1) from source at /home/rubys/git/sass-rails 
Using sdoc (0.3.20) 
Using sqlite3 (1.3.7) 
Using turbolinks (1.1.1) 
Using uglifier (2.0.1) 
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/	 db/	  Gemfile.lock	log/	 Rakefile     test/  vendor/
bin/  config.ru  Gemfile  lib/		public/  README.rdoc  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/controllers/say_controller_test.rb
      invoke  helper
      create    app/helpers/say_helper.rb
      invoke    test_unit
      create      test/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 2013-04-28 09:12:12 -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 2013-04-28 09:12:13 -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 2013-04-28 09:12:14 -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