Rails Workshop

demo.rb

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 = args[:with]
      puts "updating #{file} with:"
      puts content
      File.delete(file)
      File.open(file, 'w') do |file|
        file.write content
      end
    else
      raise ArguementError, 'Expecting with argument'
    end
    wait_for_enter
  end

  def write(file, args)
    if content = args[:with]
      puts "writing #{file} with:"
      puts content
      File.open(file, 'w') do |file|
        file.write content
      end
    else
      raise ArguementError, 'Expecting with argument'
    end
    wait_for_enter
  end

  def self.finish_up
    puts "All done!"
    wait_for_ener
    clean_up
  end

  def self.clean_up
    puts "Cleaning up!"
    `rm -rf blog`
  end

  at_exit { `cd ..`; finish_up }
end

script.rb

#!/usr/bin/env ruby
require_relative 'demo'

Demo.new do
  puts "Install Rails"
  puts "Latest version is 3.2.1"
  run "gem install rails"

  puts "Generate app named blog"
  run "rails new blog"
  puts "That made bunch of files"
  puts "The Rails skeleton"
  puts "It also installed dependencies"

  Dir.chdir "blog"
  puts "We actually have a running app"
  echo_run('rails server', 'rails server -d')
  open 'http://0.0.0.0:3000'

  puts "Lets generate a model named post"
  puts "Has a string as title and text as body"
  run "rails generate model Post title:string body:text"

  open 'app/models/post.rb'
  puts "It's empty!? Dynamic from table!"

  open 'db/migrate/*create_posts.rb'
  puts "Title, check"
  puts "Body, check"
  puts "Timestamps? Automatic!"

  puts "So what's a model do for us?"
  keynote

  puts "Lets setup our database and run migrations"
  run "rake db:migrate"

  puts "rails console"
  puts <<-CONSOLE
>> # Persistence:
>> first_post = Post.new(:title => 'First post!', :body => \"Welcome to my new blog!\nI hope you enjoy your stay!\")
>> first_post.new_record?
>> first_post.save
>> Post.count
>> first_post.new_record?
>> first_post.body = 'New post body!'
>> first_post.save
>> # Database Access:
>> Post.find(1)
>> Post.first
>> Post.all
>> # Behavior:
>> class Post
>>   def to_newspaper_format
>>     \"\#{title}\n\#{created_at}\n\n\#{body}\"
>>   end
>> end
>> puts first_post.to_newspaper_format
CONSOLE
  wait_for_enter

  # Generate controller with all our actions
  run "rails generate controller Posts index show edit update new create destroy"

  puts "What's a controller do for us?"
  keynote

  posts_controller = <<-CODE
class PostsController < ApplicationController
  def index
    @posts = Post.all
  end

  def new
    @post = Post.new
  end

  def create
    @post = Post.new(params[:post])

    if @post.save
      redirect_to @post
    else
      render :action => 'new'
    end
  end

  def show
    @post = Post.find(params[:id])
  end

  def edit
    @post = Post.find(params[:id])
  end

  def update
    @post = Post.find(params[:id])

    if @post.update_attributes(params[:post])
      redirect_to @post
    else
      render :action => 'edit'
    end
  end

  def destroy
    @post = Post.find(params[:id])
    @post.destroy

    redirect_to posts_url
  end
end
CODE
  update 'app/controllers/posts_controller.rb', with: posts_controller


  puts "What about the views?"
  keynote

  posts_index = <<-CODE
<h1>Posts</h1>
<p>
  <%= link_to 'New Post', new_post_path %>
</p>
<% @posts.each do |post| %>
  <h3><%= post.title %></h3>
  <p class="date"><%= post.created_at %></p>
  <p><%= post.body %></p>
  <p><%= link_to 'Edit', edit_post_path(post) %></p>
<% end %>
CODE
  update 'app/views/posts/index.html.erb', with: posts_index

  puts "We want RESTful routes"
  routes = <<-CODE
Blog::Application.routes.draw do
  resources :posts

  root :to => "posts#index"
end
CODE
  update 'config/routes.rb', with: routes
  run "rm public/index.html"

  posts_new = <<-CODE
<h1>Create Post</h1>
<%= form_for @post do |f| %>
  <p>
    <%= f.label :title %> <br/>
    <%= f.text_field :title %>
  </p>
  <p>
    <%= f.label :body %><br/>
    <%= f.text_area :body %>
  </p>
  <%= f.submit %>
<% end %>
CODE
  update 'app/views/posts/new.html.erb', with: posts_new

  posts_edit = <<-CODE
<h1>Editing Post</h1>
<%= render 'form', { post: @post } %>
CODE
  update 'app/views/posts/edit.html.erb', with: posts_edit

  posts_form_partial = <<-CODE
<%= form_for post do |f| %>
  <p>
    <%= f.label :title %> <br/>
    <%= f.text_field :title %>
  </p>
  <p>
    <%= f.label :body %><br/>
    <%= f.text_area :body %>
  </p>
  <%= f.submit %>
<% end %>
CODE
  write 'app/views/posts/_form.html.erb', with: posts_form_partial

  posts_new = <<-CODE
<h1>Create Post</h1>
<%= render 'form', { post: @post } %>
CODE
  update 'app/views/posts/new.html.erb', with: posts_new

  puts "Cool! We have some posts now. Lets add comments"
  run "rails generate model Comment name:string body:text post:references"
  run "rails generate controller Comments create destroy"

  open 'app/models/comment.rb'
  open 'db/migrate/*create_comments.rb'
  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

  routes = <<-CODE
Blog::Application.routes.draw do
  resources :posts do
    resources :comments
  end
end
CODE
  update 'config/routes.rb', with: routes

  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

  posts_show = <<-CODE
<h1><%= @post.title %></h1>
<p><%= @post.created_at %></p>
<p><%= @post.body %></p>
<br/>
<% @post.comments.each do |comment| %>
  <p>
    Commenter: <%= comment.name %>
  </p>
  <p>
    <%= comment.body %>
  </p>
  <p>
    <%= link_to 'Delete', [comment.post, comment], :confirm => 'Are you sure?',
                                                   :method  => :delete %>
  </p>
<% end %>
<br/>
<%= form_for [@post, @post.comments.build] do |f| %>
  <p>
    <%= f.label :name %> <br/>
    <%= f.text_field :name %>
  </p>
  <p>
    <%= f.label :comment %><br/>
    <%= f.text_area :comment %>
  </p>
  <%= f.submit %>
<% end %>
<p>
<%= link_to 'Posts', posts_path %>,
<%= link_to 'New Post', new_post_path %>
</p>
CODE
  update 'app/views/posts/show.html.erb', with: posts_show
end