Rails Workshop 2

demo.rb

require 'tempfile'

class Demo
  def initialize(&block)
    instance_eval &block
  end

  def wait_for_enter
    puts "Press enter to continue"
    gets
  end

  def keynote
    puts "Keynote!"
    wait_for_enter
  end

  def run(cmd)
    puts "$ #{cmd}"
    puts `#{cmd}`
    wait_for_enter
  end

  def echo_run(to_print, to_run)
    puts "$ #{to_print}"
    puts `#{to_run}`
    wait_for_enter
  end

  def open(file)
    puts "Check out #{file}"
    `open #{file}`
    wait_for_enter
  end

  def update(file, args)
    if content = get_contents(args)
      puts "updating #{file} with:"
      puts content
      File.delete(file)
      File.open(file, 'w') do |file|
        file.write content
      end
    end
    wait_for_enter
  end

  def write(file, args)
    if content = get_contents(args)
      puts "writing #{file} with:"
      puts content
      File.open(file, 'w') do |file|
        file.write content
      end
    end
    wait_for_enter
  end

  def patch(file, args)
    if content = get_contents(args)
      puts "Applying:"
      puts content
      Tempfile.open('patch') do |patch_file|
        patch_file.write content
        patch_file.flush
        puts `patch -p0 #{file} < #{patch_file.path}`
      end
    end
    wait_for_enter
  end


  private
  def get_contents(args)
    if content = args[:with]
      content
    else
      raise ArguementError, 'Expecting with argument'
    end
  end
end

script.rb

#!/usr/bin/env ruby
require_relative 'demo'
$dir = "blog"

Demo.new do
  puts "Get code from workshop 1"
  puts "I've put our code up in a repository on Github"
  run "git clone git://github.com/skalnik/workshop_blog.git #{$dir}"
  puts "Gives us a simple blog with posts"
  Dir.chdir $dir

  run "bundle install"
  run "rake db:create"
  run "rake db:schema:load"


  puts "Lets add comments"
  puts "We'll need assocations for this"
  keynote

  run "rails generate model Comment author:string email:string body:text post:references"

  puts "And run migrations"
  run "rake db:migrate"

  post_model = <<-CODE
class Post < ActiveRecord::Base
  has_many :comments
end
CODE
  update 'app/models/post.rb', with: post_model

  run "rails generate controller Comments create destroy"
  comments_controller = <<-CODE
class CommentsController < ApplicationController
  def create
    @post = Post.find(params[:post_id])
    @comment = @post.comments.create(params[:comment])
    redirect_to post_url(@post)
  end

  def destroy
    @post = Post.find(params[:post_id])
    @comment = @post.comments.find(params[:id])
    @comment.destroy
    redirect_to post_url(@post)
  end
end
CODE
  update 'app/controllers/comments_controller.rb', with: comments_controller

  routes = <<-CODE
WorkshopBlog::Application.routes.draw do
  resources :posts do
    resources :comments
  end

  root to: 'posts#index'
end
CODE
  update 'config/routes.rb', with: routes
  puts "We won't use all the actions on comments, but lets just keep it simple"

  post_show = <<-CODE
<%= render 'post', :post => @post %>
<%= form_for [post, comment] do |f| %>
  <p>
    <%= f.label :author, 'Name' %><br />
    <%= f.text_field :author %>
  </p>
  <p>
    <%= f.label :email %><br />
    <%= f.text_field :email %>
  </p>
  <p>
    <%= f.label :body %><br />
    <%= f.text_area :body%>
  </p>
<% end %>
<%= link_to 'Home', posts_path %>
CODE
  update 'app/views/posts/show.html.erb', with: post_show

  puts "Lets get some validations on those comments"
  keynote

  comment_validations = <<-DIFF
--- app/models/comment.rb
+++ app/models/comment.rb
@@ -1,3 +1,7 @@
 class Comment < ActiveRecord::Base
   belongs_to :post
+
+  validates_presence_of :body, :author
+  validates :email, :presence => true,
+                    :format   => { :with => /^[^@]+@[^@]+$/ }
 end
DIFF
  patch 'app/models/comment.rb', with: comment_validations

  post_validations = <<-DIFF
--- app/models/post.rb
+++ app/models/post.rb
@@ -1,2 +1,3 @@
 class Post < ActiveRecord::Base
+  validates_presence_of :title, :author, :body
 end
DIFF
  patch 'app/models/post.rb', with: post_validations

  puts "Lets add some basic authentication"
  posts_controller_authentication = <<-DIFF
--- app/controllers/posts_controller.rb
+++ app/controllers/posts_controller.rb
@@ -1,6 +1,9 @@
 class PostsController < ApplicationController
   before_filter :find_post, :only => [:show, :edit, :update, :destroy]

+  http_basic_authenticate_with :name => 'skalnik', :password => 'sekret',
+                               :except => [:index, :show]
+
   def index
     @posts = Post.all
   end
DIFF
  patch 'app/controllers/posts_controller.rb', with: posts_controller_authentication

  comments_controller_authentication = <<-DIFF
--- app/controllers/comments_controller.rb
+++ app/controllers/comments_controller.rb
@@ -1,4 +1,5 @@
 class CommentsController < ApplicationController
+  http_basic_authenticate_with :name => 'skalnik', :password => 'sekret'
   def create
     @post = Post.find(params[:post_id])
     @comment = @post.comments.create(params[:comment])
DIFF
  patch 'app/controllers/comments_controller.rb', with: comments_controller_authentication
end

def finish_up
  puts "All done!"
  clean_up
end

def clean_up
  puts "Cleaning up!"
  puts `rm -rf #{$dir}`
end

at_exit { Dir.chdir '..'; finish_up }