Agile Web Development with Rails, Edition 4

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

2 Instant Gratification

ArgumentError: assertion message must be String or Proc: <<"Hello from Rails!"> expected but was
<"Internal Server Error">.>(<Test::Unit::Assertions::AssertionMessage>)

Traceback:
  /home/rubys/git/awdwr/edition4/checkdepot.rb:14:in `block in <class:DepotTest>'

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/bin/rails new demo1 --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)

Using abstract (1.0.0)

Using activesupport (3.0.10)

Using builder (2.1.2)

Using i18n (0.5.0)

Using activemodel (3.0.10)

Using erubis (2.6.6)

Using rack (1.2.4)

Using rack-mount (0.6.14)

Using rack-test (0.5.7)

Using tzinfo (0.3.30)

Using actionpack (3.0.10)

Using mime-types (1.16)

Using polyglot (0.3.2)

Using treetop (1.4.10)

Using mail (2.2.19)

Using actionmailer (3.0.10)

Using braintree (2.12.0)

Using activemerchant (1.10.0)

Using arel (2.0.10)

Using activerecord (3.0.10)

Using activeresource (3.0.10)

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 haml (3.1.3)

Using htmlentities (4.3.0)

Using json (1.6.1)

Using rdoc (3.11)

Using thor (0.14.6)

Using railties (3.0.10)

Using rails (3.0.10)

Using jquery-rails (0.2.7)

Using mysql (2.8.1)

Using sqlite3 (1.3.4)

Using test-unit (2.4.0)

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

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

Internal Server Error

wrong number of arguments (2 for 1)

WEBrick/1.3.1 (Ruby/1.9.4/2011-10-18) at localhost:3000

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

Internal Server Error

wrong number of arguments (2 for 1)

WEBrick/1.3.1 (Ruby/1.9.4/2011-10-18) at localhost:3000

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

Internal Server Error

wrong number of arguments (2 for 1)

WEBrick/1.3.1 (Ruby/1.9.4/2011-10-18) at localhost:3000

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

Internal Server Error

wrong number of arguments (2 for 1)

WEBrick/1.3.1 (Ruby/1.9.4/2011-10-18) at localhost:3000

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

Internal Server Error

wrong number of arguments (2 for 1)

WEBrick/1.3.1 (Ruby/1.9.4/2011-10-18) at localhost:3000

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

Internal Server Error

wrong number of arguments (2 for 1)

WEBrick/1.3.1 (Ruby/1.9.4/2011-10-18) at localhost:3000

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

Internal Server Error

wrong number of arguments (2 for 1)

WEBrick/1.3.1 (Ruby/1.9.4/2011-10-18) at localhost:3000

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