random personal notes and reminders related to my funny adventures with Rails

DRY database.yml

# inheritance in yml files:

development: &defaults
  adapter: mysql
  encoding: utf8
  database: acme_development
  username: root

test:
  <<: *defaults
  database: acme_test

cucumber:
  <<: *defaults
  database: acme_cucumber

DRY using modules.rb

# based on: http://handyrailstips.com/tips/14-drying-up-your-ruby-code-with-modules

# in model User:
class User < ActiveRecord::Base
  include SpaceStripper
end


# in model Comment:
class Comment < ActiveRecord::Base
  include SpaceStripper
end


# in lib/space_stripper.rb:
module SpaceStripper
  before_save :strip_spaces_from_name
  def strip_spaces_from_name
    name = self.name.strip
  end
end

DRY views.rdoc

DRY with block helpers:¶ ↑

source: github.com/markevans/block_helpers article: blog.new-bamboo.co.uk/2009/8/14/block-helpers

In Gemfile¶ ↑

gem "block_helpers"

In application_helper.rb¶ ↑

class MyBlockHelper < BlockHelpers::Base
  def hello(name)
    "<div style='background: gray'><i>Hi there #{name}!</i></div>" 
  end

  def to_s
  end

  def display(body)
    raw %(
      <div class="tl">
        <div class="tr">
          <div class="bl">
            <div class="br">
              #{body}
            </div>
          </div>
        </div>
      </div>
    )
  end    

end

In view.html.haml¶ ↑

=my_block_helper do |h|
  Here goes
  = h.hello('Marmaduke')
  hooray!

Result¶ ↑

<div class="tl">
  <div class="tr">
    <div class="bl">
      <div class="br">
        Here goes
          <div style="background: gray"><i>Hi there Marmaduke!</i></div>
        hooray!
      </div>
    </div>
  </div>
</div>

erb2haml.rb

# run this script in the rails project folder, and all erb files will be converted to haml
# erb files are not removed, you'll have to delete the manually

class ToHaml
  def initialize(path)
    @path = path
  end
  
  def convert!
    Dir["#{@path}/**/*.erb"].each do |file|
      `html2haml -rx #{file} #{file.gsub(/\.erb$/, '.haml')}`
    end
  end
end

path = File.join(File.dirname(__FILE__), 'app', 'views')
ToHaml.new(path).convert!

i18n-scoping_routes.rb

# In config/routes.rb :

  scope ':locale', :locale => /en|fr|es|nl/ do
    resources :movies
  end


# In app/controllers/application_controller.rb :

  before_filter :set_locale
  
  def set_locale
    I18n.locale = params[:locale]
  end
  
  def default_url_options(options={})
    logger.debug "default_url_options is passed options: #{options.inspect}\n"
    { :locale => I18n.locale }
  end
  

model_validations.rb

class Product < ActiveRecord::Base

  validates :title, :description, :image_url, :presence => true
  validates :price, :numericality => {:greater_than_or_equal_to => 0.01}
  validates :title, :uniqueness => true

  validates :image_url, :format => {
    :with => %r{\.(gif|jpg|png)$}i,
    :message => 'must be a URL for GIF, JPG or PNG image.'
  }

end

railsapp_generator.sh

# usage: 
# curl https://gist.github.com/raw/772145/railsapp_generator.sh | bash -s {APPNAME}

APP=$1
mkdir $APP
cd $APP
gem install rails --no-rdoc --no-ri
rails new . -T # note: -T switch removes the Test::Unit stuff
rvm gemset create $APP
echo "rvm ruby-1.9.2-p0@$APP" > .rvmrc

echo "export rvm_pretty_print_flag=1" >> .rvmrc
rvm use 1.9.2-p0@$APP

gem install bundler --no-rdoc --no-ri

echo "

#views -------------
gem 'haml-rails'
gem "jquery-rails"
#gem 'compass'
gem 'formtastic'
gem 'will_paginate'
gem 'block_helpers'

#sys ---------------
gem 'capistrano'
gem 'mysql2'
gem 'thin'

#auth --------------
gem 'devise'
gem 'hpricot'          # required by devise
gem 'ruby_parser'      # required by devise

#admin -------------
# gem 'rails_admin', :git => 'git://github.com/sferik/rails_admin.git'

#dev ---------------
group :development, :test do
  gem 'rspec-rails'
  gem 'autotest-rails' # see: https://gist.github.com/365816
  gem 'autotest'  
  gem 'cucumber-rails'
  gem 'database_cleaner'
  gem 'webrat'
  gem 'selenium-client'
  # using test_notifier: https://github.com/fnando/test_notifier
end
" >> Gemfile


"
Autotest.add_hook :initialize do |autotest|
  %w{.git .svn .hg .DS_Store ._* vendor tmp log doc}.each do |exception|
    autotest.add_exception(exception)
  end
end
" >> .autotest


git init .

echo "bundle in 5 seconds"; sleep 1s
echo "bundle in 4 seconds"; sleep 1s
echo "bundle in 3 seconds"; sleep 1s
echo "bundle in 2 seconds"; sleep 1s
echo "bundle in 1 second";  sleep 1s


bundle install

echo "
next steps:
-----------
rails g rspec:install
rails g cucumber:install
rails g formtastic:install
rails g jquery:install 
"

refinery_cms.rb

# source: http://groups.google.com/group/refinery-cms/browse_thread/thread/35f962b53b5bed74#
# The plans for Refinery? You can either install the refinery gem and ask it to generate you an application using: 

#    $ refinerycms /path/to/my/app 

# or you can plug it into an existing Rails application by putting this in your Gemfile: 

    gem 'refinerycms', :git => 'git://github.com/resolve/refinerycms.git', :branch => 'master' 

# Then run: 

#    $ bundle install 
#    $ rails generate refinerycms 
#    $ rake db:migrate 
#    $ rake db:seed # (optional) 

seeds_example.rb

# usage: rake db:seed

#---
# Excerpted from "Agile Web Development with Rails, 4rd Ed.",
# published by The Pragmatic Bookshelf.
# Copyrights apply to this code. It may not be used to create training material, 
# courses, books, articles, and the like. Contact us if you are in doubt.
# We make no guarantees that this code is fit for any purpose. 
# Visit http://www.pragmaticprogrammer.com/titles/rails4 for more book information.
#---
# encoding: utf-8
Product.delete_all
Product.create(:title => 'Web Design for Developers',
  :description => 
    %{<p>
        <em>Web Design for Developers</em> will show you how to make your
        web-based application look professionally designed. We'll help you
        learn how to pick the right colors and fonts, avoid costly interface
        and accessibility mistakes -- your application will really come alive.
        We'll also walk you through some common Photoshop and CSS techniques
        and work through a web site redesign, taking a new design from concept
        all the way to implementation.
      </p>},
  :image_url =>   '/images/wd4d.jpg',    
  :price => 42.95)
# . . .
Product.create(:title => 'Programming Ruby 1.9',
  :description =>
    %{<p>
        Ruby is the fastest growing and most exciting dynamic language
        out there. If you need to get working programs delivered fast,
        you should add Ruby to your toolbox.
      </p>},
  :image_url => '/images/ruby.jpg',
  :price => 49.50)
# . . .

Product.create(:title => 'Rails Test Prescriptions',
  :description => 
    %{<p>
        <em>Rails Test Prescriptions</em> is a comprehensive guide to testing
        Rails applications, covering Test-Driven Development from both a
        theoretical perspective (why to test) and from a practical perspective
        (how to test effectively). It covers the core Rails testing tools and
        procedures for Rails 2 and Rails 3, and introduces popular add-ons,
        including Cucumber, Shoulda, Machinist, Mocha, and Rcov.
      </p>},
  :image_url => '/images/rtp.jpg',
  :price => 43.75)

various notes.rdoc

Advanced find_or_create¶ ↑

It does not work for protected attributes, but you can pass those in a block, eg.

user = User.find_or_create_by_screen_name( 
  :screen_name => "atog", 
  :name => "Koen Van der Auwera"
) {|u| u.admin = true }

.gitconfig:¶ ↑

# in home directory:

user

name = {FIRSTNAME LASTNAME} email = {EMAIL}

in Capfile:¶ ↑

set :keep_releases, 3

in .rvmrc:¶ ↑

rvm ruby-1.9.2-p0@ubuapp
export rvm_pretty_print_flag=1

Notes to self inside code¶ ↑

# TODO = Things you still need to do.
# OPTIMIZE = Code you need to clean-up, refactor etc.
# FIXME = Mark a bug or method that needs to be fixed.

then, use:

$ rake notes

Writing migrations quicker¶ ↑

rails generate migration add_quantity_to_line_item quantity:integer

The two patterns that Rails matches on is add_XXX_to_TABLE and remove_XXX_from_TABLE where the value of XXX is ignored: what matters is the list of column names and types that appear after the migration name.

The only thing Rails can’t tell is what a reasonable default is for this column. In many cases a null value would do, but let’s make it the value one for existing carts by modifying the migration before we apply it: media.pragprog.com/titles/rails4/code/depot_g/db/migrate/20100301000004_add_quantity_to_line_item.rb

Testing¶ ↑

the standard set of Test::Unit assertions:

assert(boolean, message=nil)
assert_block(message="assert_block failed.") do ... end
assert_equal(expected, actual, message=nil)
assert_in_delta(expected_float, actual_float, delta, message="")
assert_instance_of(klass, object, message="")
assert_kind_of(klass, object, message="")
assert_match(pattern, string, message="")
assert_nil(object, message="")
assert_no_match(regexp, string, message="")
assert_not_equal(expected, actual, message="")
assert_not_nil(object, message="")
assert_not_same(expected, actual, message="")
assert_nothing_raised(*args) do ... end
assert_nothing_thrown(message="") do ... end
assert_operator(object1, operator, object2, message="")
assert_raise(expected_exception_klass, message="") do ... end
assert_respond_to(object, method, message="")
assert_same(expected, actual, message="")
assert_send(send_array, message="")
assert_throws(expected_symbol, message="") do ... end

running 1 test:

$ ruby -Itest test/unit/article_test.rb

Example¶ ↑

gist.github.com/358401

Cheat sheet¶ ↑

nubyonrails.com/articles/ruby-rails-test-rails-cheat-sheet